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The chemistry of (P,C)-cyclometalated complexes derived from naphthyl phosphines [Np(P,C)M] is presented and analysed in this review. The three main synthetic approaches, namely P-chelation assisted C–H activation, oxidative addition and transmetalation, are described and compared. If a naphthyl framework inherently predisposes a phosphorus atom and transition metal to interact, a rigid metallacycle may induce some strain and distortion, as apparent from the survey of the single-crystal X-ray diffraction structures deposited in the Cambridge Structural Database (77 entries with metals from groups 7 to 11). Generally, the Np(P,C)-cyclometalation imparts high thermal and chemical robustness to the complexes, and a variety of stoichiometric reactions have been reported. In most cases, the metalacyclic structure is retained, but protodecyclometalation and ring-expansion have been sparingly observed. [Np(P,C)M] complexes have also proved to be competent and actually competitive catalysts in several transformations, and they act as key intermediates in some others. In addition, interesting phosphorescence properties have been occasionally pointed out. [ABSTRACT FROM AUTHOR]

Transition metal coordination chemistry and catalysis are rife with phosphine ligands. One of the rather less studied members of the phosphine ligand family are phosphine aldehydes. We have synthesised 3-(diphenylphosphino)propanal (PCHO) with a slight modification of the known procedure and studied its complexation behaviour with palladium(II) and platinum(II). The catalytic activity of the palladium(II) phosphine aldehyde complexes was investigated in Cu-free Sonogashira and Suzuki–Miyaura cross-coupling reactions. Furthermore, the homogeneous nature of the catalytically active species was confirmed. [ABSTRACT FROM AUTHOR]

This invited Team Profile was created by the Gessner and Gooßen research groups at Ruhr‐University Bochum (Germany). They recently published a series of articles in Angewandte Chemie on the application of ylide‐substituted phosphines (YPhos) in palladium‐catalyzed coupling reactions. Owing to their inherently strong sigma‐donating ability and their modular synthesis, YPhos ligands can be tailored to fit the demands of various catalytic transformations. In the most recent article, machine learning methods were applied to identify a YPhos catalyst that enables the previously elusive Hiyama coupling of aryl chlorides. "Computer‐Driven Development of Ylide Functionalized Phosphines for Palladium‐Catalyzed Hiyama Couplings", J. F. Goebel, J. Löffler, Z. Zeng, J. Handelmann, A. Hermann, I. Rodstein, T. Gensch, V. H. Gessner, L. J. Gooßen, Angew. Chem. Int. Ed. 2023, e202216160; Angew. Chem. 2023, e202216160. [ABSTRACT FROM AUTHOR]

This invited Team Profile was created by the Gessner and Gooßen research groups at Ruhr‐University Bochum (Germany). They recently published a series of articles in Angewandte Chemie on the application of ylide‐substituted phosphines (YPhos) in palladium‐catalyzed coupling reactions. Owing to their inherently strong sigma‐donating ability and their modular synthesis, YPhos ligands can be tailored to fit the demands of various catalytic transformations. In the most recent article, machine learning methods were applied to identify a YPhos catalyst that enables the previously elusive Hiyama coupling of aryl chlorides. "Computer‐Driven Development of Ylide Functionalized Phosphines for Palladium‐Catalyzed Hiyama Couplings", J. F. Goebel, J. Löffler, Z. Zeng, J. Handelmann, A. Hermann, I. Rodstein, T. Gensch, V. H. Gessner, L. J. Gooßen, Angew. Chem. Int. Ed. 2023, e202216160; Angew. Chem. 2023, e202216160. [ABSTRACT FROM AUTHOR]

Ylide‐functionalized phosphines (YPhos) have recently proven to be strongly donating ligands that enable high catalyst activities in gold(I)‐mediated transformations. We now report on a calorimetric study dealing with the [Au(YPhos)Cl] system and assess YPhos‐Au bond dissociation enthalpies (BDE). Comparison with other commonly used phosphines confirmed the high binding strengths of the YPhos ligands. Furthermore, the values of the reaction enthalpies were shown to correlate with the electronic properties of the ligands measured via the Tolman electronic parameter or the calculated molecular electrostatic potential at phosphorus. Notably, the reaction enthalpies can conveniently be derived by computational methods, thus making these easy‐to‐obtain descriptors for ligand donor property quantification. [ABSTRACT FROM AUTHOR]

The construction of diaryl alkanes from aromatic aldehydes or ketones with electron-deficient arenes is achieved in the presence of trivalent phosphine under electrochemical conditions. Reductive coupling between electron-deficient arenes and the carbonyl groups of aldehydes or ketones occurs at the cathode to yield diaryl alcohols. At the anode, the trivalent phosphine reagent may undergo single-electron oxidation to generate its radical cation, which reacts with the diaryl alcohols to form dehydroxylated products. [ABSTRACT FROM AUTHOR]

A palladium-catalysed aromative benzylic allylation and allenylation of benzyl chlorides with allyl and allenyl pinacolborates is described for the first time. The reactions proceed smoothly in the presence of a bidentate phosphine ligand to afford normal cross-coupling products in good yields. This novel synthetic procedure exhibits good tolerance for various electron-withdrawing and -donating functional groups linked to aromatic rings and is also well tolerant of sensitive functional groups such as NO2, CF3, CN, and COOMe. The utilisation of a bidentate ligand and heating are essential to transformation. The DFT calculation results reveal that wide-bite-angle bidentate ligands are beneficial to the formation of an η1-benzyl-η1-allylpalladium intermediate and that the normal coupling is thermodynamically favourable. [ABSTRACT FROM AUTHOR]

Catalytic enantioselective coupling of 1,1‐disubstituted allenes and aldehydes through regiodivergent oxidative cyclization followed by stereoselective protonation or reductive elimination promoted by chiral phosphine‐Co complexes is presented. Such processes represent unprecedented and unique reaction pathways for Co catalysis that enable catalytic enantioselective generation of metallacycles with divergent regioselectivity accurately controlled by chiral ligands, affording a wide range of allylic alcohols and homoallylic alcohols that are otherwise difficult to access without the need of pre‐formation of stoichiometric amounts of alkenyl‐ and allyl‐metal reagents in up to 92 % yield, >98 : 2 regioselectivity, >98 : 2 dr and >99.5 : 0.5 er. [ABSTRACT FROM AUTHOR]

In the absence of strong ancillary ligands such as phosphines or N‐heterocyclic carbenes, palladium salts are selective for C−OTf cleavage in the room‐temperature Suzuki couplings of chloroaryl triflates in acetonitrile. Similar "ligand‐free" conditions in DMSO also promote triflate‐selective Suzuki coupling of bromoaryl triflates. This triflate selectivity complements the typical preference for reaction of bromides in prior reports of Suzuki couplings using phosphine ligands. DFT calculations and additional experimental evidence are consistent with triflate‐selective oxidative addition taking place at homogeneous, possibly mononuclear, anionic palladium supported by a solvent molecule. [ABSTRACT FROM AUTHOR]

The chlorination of 1,2‐diphosphinobenzene with PCl5 to 1,2‐bis(dichlorophosphino)benzene was performed with high yields (93 %) despite the high number of P−H functions. The method was further applied to other phosphanes, enabling the first synthesis and complete characterization of 1,2,4‐tris(dichlorophosphino)benzene (89 % yield) and 1,2,4,5‐tetrakis(dichlorophosphino)benzene (91 % yield), valuable precursors for example for binuclear complexes, coordination polymers, organic wires, or metal–organic frameworks. The application of the chlorophosphanes in base induced ring closure reactions with primary amines is demonstrated. [ABSTRACT FROM AUTHOR]

Bulky ylide‐substituted phosphines have recently found application as potent ligands in homogeneous catalysis. The attempted synthesis of the ylide‐substituted fluorenylphosphine YPhP(Cy)Flu [YPh=Cy3P(Ph)C; Flu=9‐methylfluorenyl] now resulted in the unexpected elimination of 9‐methylenefluorene during the deprotonation step of the intermediary α‐phosphino phosphonium salt to yield the secondary ylide‐substituted phosphine YPhP(Cy)H. This phosphine underwent formal H2 elimination under basic conditions to form a cyclic phosphonium ylide with a P−C−P−C four‐membered ring via deprotonation of one cyclohexyl group of the PCy3 moiety. Upon coordination to transition metals the secondary ylidylphosphine forms a neutral phosphide ligand by shift of the proton into the ylide‐backbone and formation of zwitterionic metal complexes. [ABSTRACT FROM AUTHOR]

Metal complexes feature a wide range of available geometries, diversified lability, controllable hydrolytic stability, and easily available rich redox activity. These characteristics, combined with the specific properties of coordinated organic molecules, result in many different mechanisms of biological action, making each of the myriads of the classes of metal coordination compounds unique. This focused review presents combined and systematized results of the studies of a group of copper(I) (pseudo)halide complexes with aromatic diimines and tris(aminomethyl)phosphines of a general formula [CuX(NN)PR3], where X = I− or NCS−, NN = 2,2′-bipyridyl, 1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline or 2,2′-biquinoline, and PR3 = air-stable tris(aminomethyl)phosphines. The structural and electronic properties of the phosphine ligands and luminescent complexes are discussed. The complexes with 2,9-dimethyl-1,10-phenanthroline, apart from being air- and water-stable, exhibit a very high in vitro antimicrobial activity against the Staphylococcus aureus and Candida albicans. Moreover, some of these complexes also show a strong in vitro antitumor activity against human ovarian carcinoma cell lines: MDAH 2774 and SCOV 3, CT26 (mouse colon carcinoma), and A549 (human lung adenocarcinoma) cell lines. The tested complexes are moderately able to induce DNA lesions through free radical processes, however the trends do not reflect observed differences in biological activity. [ABSTRACT FROM AUTHOR]

We report a proximity-driven crosslinking strategy featuring bioorthogonal cyclopropenones. These motifs react with phosphines to form electrophilic ketene-ylides. Such intermediates can be trapped by neighboring proteins to form covalent adducts. Successful crosslinking was achieved using a model split reporter, and the rate of crosslinking could be tuned using different phosphine triggers. We further demonstrated that the reaction can be performed in cell lysate. Based on these features, we anticipate that cyclopropenones will enable unique studies of protein-protein and other biomolecule interactions.

Secondary phosphines are important building blocks in organic chemistry as their reactive P—H bond enables construction of more elaborate molecules. In particular, they can be used to construct tertiary phosphines that have widespread applications as organocatalysts, and as ligands in metal-complex catalysis. We report here a practical synthesis of the bulky secondary phosphine synthon 2,2,6,6-tetramethylphosphinane (TMPhos). Its nitrogen analogue tetramethylpiperidine, known for over a century, is used as a base in organic chemistry. We obtained TMPhos on a multigram scale from an inexpensive air-stable precursor, ammonium hypophosphite. TMPhos is also a close structural relative of di-tert-butylphosphine, a key component of many important catalysts. Herein we also describe the synthesis of key derivatives of TMPhos, with potential applications ranging from CO2 conversion to cross-coupling and beyond. The availability of a new core phosphine building block opens up a diverse array of opportunities in catalysis. Di-tert-butylphosphine is an important substituent in many phosphine ligands, however, its heterocyclic analogues have not yet been isolated. Here, the authors report the synthesis and isolation of 2,2,6,6-tetramethylphosphinane on a gram scale starting from ammonium hypophosphite, and its facile use as a building block in ligand construction. [ABSTRACT FROM AUTHOR]

Combination of a phosphinidene precursor, B(C6F5)3 and 4-ethynyltoluene afforded the FLP addition product, Et2N(C14H10)PC(Tol)＝CH (B(C6F5)3) 2. Compound 2 reacted with halides, pseudo-halides or Me3SiSPh to provide a facile route to the salts of anionic phosphines while reaction with PEt3 gave the zwitterion Et3PCH＝C(SiMe3)P(NEt2)C(Tol)＝CHB(C6F5)38. This latter species reacted with an alkyne to give a phosphine donor with both olefin-linked cationic and anionic substituents. [ABSTRACT FROM AUTHOR]

The electronic features of gold‐aluminyl complexes have been thoroughly explored. Their similarity with Group 14 dimetallenes and other metal‐aluminyl complexes suggests that their reactivity with small molecules beyond carbon dioxide could be accessed. In this work, the reactivity of the [tBu3PAuAl(NON)] (NON=4,5‐bis(2,6 diisopropylanilido)‐2,7‐ditert‐butyl‐9,9‐dimethylxanthene) complex towards water, ammonia, sulfur dioxide and nitrous oxide is computationally explored. The reaction mechanisms computed for each substrate strongly suggest that all activation processes are in principle experimentally feasible. Electronic structure analysis highlights that, in all cases, the reactivity is driven by the presence of the poorly polarized electron‐sharing gold‐aluminyl bond, which induces a radical‐like reactivity of the complex towards all the substrates. A flat topology of the potential energy surface (PES) has been found for the reaction with N2O, where two almost isoenergetic transition states can be located along the same reaction coordinate with different geometries, suggesting that the N2O binding mode may not be a good indicator of the nature of N2O activation in a cooperative bimetallic reactivity. In addition, the catalytic potentialities of these complexes have been explored in the framework of nitrous oxide reduction. The study reveals that the [tBu3PAuAl(NON)] complex might be an efficient catalyst towards oxidation of phosphines (and boranes) via N2O reduction. These findings underline recurring trends in the novel chemistry of gold‐aluminyl complexes and call for experimental feedbacks. [ABSTRACT FROM AUTHOR]

Precise control of molecule‐electrode interface is essential for molecular devices. Herein, new ruthenium acetylide molecular wires with long‐legged phosphine ligands to form a sterically controlled molecule‐electrode interface are designed. The sharpened Raman signals ascribed to acetylene stretching are observed for the self‐assembled monolayers (SAMs) of the molecular wires with the biphenyl‐ (2Au) and tert‐butylbiphenyl‐substituted long‐legged dppe‐type ligands (3Au), suggesting that steric hindrance causes formation of uniform SAMs. Scanning tunneling microscope break‐junction (STM‐BJ) study of 3Au reveals narrow conductance features compared with those of 1Au bearing the parent dppe ligands, indicating formation of a uniform molecular junction. Furthermore, the effective electronic interactions between the molecule and electrodes are unique to the long‐legged derivatives, as revealed by the surface‐enhanced Raman scattering study. Thus, the bulky long‐legged strategy turns out to provide a design concept for a well‐defined molecule‐electrode interface. [ABSTRACT FROM AUTHOR]

A chiral Brønsted acid‐catalysed asymmetric hydrophosphinylation of 2‐vinylazaarenes by secondary phosphine oxides is described. A variety of P‐chiral 2‐azaaryl‐ethylphosphine oxides are synthesized with high yields and ees, of which both the substituents of phosphines and azaarenes can be flexibly modulated, underscoring an exceptionally broad scope of substrates. These adducts are valuable to asymmetric metal catalysis since the resultant P‐chiral tertiary phosphines from the reduction of them are verified as a kind of effective C1‐symmetric chiral 1,5‐hybrid P,N‐ligands. Importantly, this catalysis platform enables the generic and efficient kinetic resolution of P‐chiral secondary phosphine oxides. It thus provides an expedient approach to access the enantiomers of the P‐chiral tertiary phosphine oxides derived from asymmetric hydrophosphinylation, further improving the utility of the method. [ABSTRACT FROM AUTHOR]

Thiourea‐based iminophosphorane (BIMP) organocatalysts featuring SPhos‐ or BIDIME phosphine units have been developed and successfully applied in the asymmetric addition of nitromethane to N‐Boc‐protected trifluoromethyl aryl ketimines. α‐Trifluoromethyl β‐nitroamines were obtained in 40–82% isolated yields and 80–95% enantioselectivities. A careful evaluation of the catalytic activity of BIMPs indicates that the catalysts derived from the combination via Staudinger reaction of a chiral 1,2‐amino alcohol‐derived thiourea‐organoazide with electron‐rich phosphines, promote the aza‐Henry reaction on fluorinated ketimines with the highest enantioselectivity, leading to the amine featuring a tetrasubstituted stereocenter in up to 95% ee. The reaction was performed also on gram scale, without loss of enantioselectivity. [ABSTRACT FROM AUTHOR]

A highly selective, efficient and practical method for synthesizing primary alcohols was presented. By using cheap Fe(BF4)2 ⋅ 6H2O and /tris[2‐(diphenylphosphino)phenyl]phosphine (L1) as catalysts with formic acid as hydrogen source, a variety of primary alcohols bearing versatile functional groups could be obtained from both alkyl‐ and aryl‐substituted epoxides under mild conditions. [ABSTRACT FROM AUTHOR]

The chemistry of the rhenium trihydrido complex [ReH3(PPh3)4] (1) has been reinvestigated. An improved synthesis and the solid‐state structure of the compound as well as several reactions are reported. The solid‐state structure of 1 is similar to that of [TcH3(PPh3)4] having a capped‐octahedral coordination sphere. The PPh3 ligands surround the Re atom in a trigonal‐pyramidal mode with a short apical Re−P bond (2.300(2) Å) and three longer basal bonds (2.429(2)–2.449(2) Å). Reactions of 1 with monodentate phosphines such as PMe3 or PBu3 give the mono‐substituted complexes [ReH3(PPh3)3(PMe3)] (2) and [ReH3(PPh3)3(PBu3)] (3) under retention of the apical PPh3 ligand and substitution of one of the basal PPh3 ligands. The stability of the phosphine trihydride complexes decreases in the order PPh3>PMe3>PBu3. Treatment of [ReH3(PPh3)4] with trityl hexafluorophosphate in CH3CN does not result in a hydride abstraction, but gives the tetrahydrido cation [ReH4(NCCH3)(PPh3)3]+ (4), while reactions with nitriles give unstable azavinylidene complexes of the composition [ReH2(PPh3)3(NC(H)R)] (5). They are formed by an insertion of the nitrile into a Re−H bond. The solid‐state structure of the methyl derivative [ReH2(PPh3)3(NC(H)CH3)] (5 a) was determined showing a linear Re−N−C unit with rhenium−nitrogen and nitrogen−carbon double bonds, while the N=CH−C bond is clearly bent with an angle of 124°. Two previously unknown polymorphs of [ReH5(PPh3)3] were isolated from reactions of 1 with HOC6H3(CH3)2 and thiourea after prolonged heating in toluene and characterized by IR spectroscopy and X‐ray diffraction. [ABSTRACT FROM AUTHOR]

In these studies, we designed and investigated cyto- and genotoxic potential of five ruthenium cyclopentadienyl complexes bearing different phosphine and phosphite ligands. All of the complexes were characterized with spectroscopic analysis (NMR, FT-IR, ESI-MS, UV-vis, fluorescence and XRD (for two compounds)). For biological studies, we used three types of cells – normal peripheral blood mononuclear (PBM) cells, leukemic HL-60 cells and doxorubicin-resistance HL-60 cells (HL-60/DR). We compared the results obtained with those obtained for the complex with maleimide ligand CpRu(CO)2(η1-N-maleimidato) 1, which we had previously reported. We observed that the complexes CpRu(CO)(PPh3)(η1-N-maleimidato) 2a and CpRu(CO)(P(OEt)3)(η1-N-maleimidato) 3a were the most cytotoxic for HL-60 cells and non-cytotoxic for normal PBM cells. However, complex 1 was more cytotoxic for HL-60 cells than complexes 2a and 3a (IC50 = 6.39 μM vs. IC50 = 21.48 μM and IC50 = 12.25 μM, respectively). The complex CpRu(CO)(P(OPh)3)(η1-N-maleimidato) 3b is the most cytotoxic for HL-60/DR cells (IC50 = 104.35 μM). We found the genotoxic potential of complexes 2a and 3a only in HL-60 cells. These complexes also induced apoptosis in HL-60 cells. Docking studies showed that complexes 2a and CpRu(CO)(P(Fu)3)(η1-N-maleimidato) 2b have a small ability to degrade DNA, but they may cause a defect in DNA damage repair mechanisms leading to cell death. This hypothesis is corroborated with the results obtained in the plasmid relaxation assay in which ruthenium complexes bearing phosphine and phosphite ligands induce DNA breaks. [ABSTRACT FROM AUTHOR]

Diphosphine ligands containing {(−HC=N) imine group} demonstrating aliphatic and aromatic framework such as ethane and azobenzene exhibit different nonlinear optical (NLO) properties. In this study, two different ligands N,N′‐Bis‐(2‐diphenylphosphinobenzyaldehyde)‐ethane‐1,2‐diamine (A) and N,N′‐Bis‐(2‐diphenylphosphinobenzyaldehyde)‐4,4 azodianiline (B) have been synthesized with a percentage yield of 60–70 % and further characterized by spectroscopic analysis. Comparative study of computational analysis using Gaussian software with DFT method and hybrid functional B3LYP together with basis set 6‐31G++(d,p) has shown good agreement of less than 5 % deviation errors. From previous study, derivatives of these compounds have shown good NLO properties contributing by many factors such as conjugation, electron withdrawing groups (EWG), electron donating groups (EDG), metal mass, highest occupied molecular orbital‐lowest unoccupied orbital (HOMO‐LUMO) and band gap. The evaluation shows that both ligands have high NLO properties established on the value of βtot at 1064 nm wavelength. Studies indicate that ligand B showed highest NLO property with the βtot value of 11.1534×10−30 esu followed by ligand A 10.3786×10−30 esu due to increased conjugation in the system. This is supported by the high dipole moment 5.501404 μ (D) of ligand B. These ligands can be further modified by the addition of the metals to form complexes in order to improve NLO properties with the βtot value of complex A 24.0638×10−30 esu followed by complex B with the βtot value 526.9826×10−30 esu. [ABSTRACT FROM AUTHOR]

Pd‐catalyzed nucleophilic fluorination reactions are important methods for the synthesis of fluoroarenes and fluoroalkenes. However, these reactions can generate a mixture of regioisomeric products that are often difficult to separate. While investigating the Pd‐catalyzed fluorination of cyclic vinyl triflates, we observed that the addition of a substoichiometric quantity of TESCF3 significantly improved the regioselectivity of the reaction. Herein, we report a combined experimental and computational study on the mechanism of this transformation focusing on the role of TESCF3. The poor regioselectivity of the reaction in the absence of additives results from the formation of LPd‐cyclohexyne complexes (L=biaryl monophosphine ligand). When TESCF3 is added to the reaction mixture, the generation of the Pd‐cyclohexyne complexes is diminished by an unexpected pathway involving the dearomatization of the ligand by nucleophilic attack from a trifluoromethyl anion (CF3−). [ABSTRACT FROM AUTHOR]

The packing states of luminescent molecules can be affected by external stimuli, leading to changes in the emission energy. Compared with the traditional organics and metal−organic frameworks, closely packed coordination polymers (CPs) have more transition types and better stabilities, respectively. However, little attention is paid to the closely packed CPs in the field of piezochromism, and much less to the corresponding optical mechanism. For studying the effect of molecular structure and the energy transfer on piezochromism, ten [Cu2I2] cluster‐based CPs with bridging aromatic ligands and terminal triphenylphosphine ligands are constructed to explore the pressure‐dependent luminescence, especially the influences of bridging ligand length, supramolecular interactions, and halogen atoms on the wavelength shift for luminescent piezochromism. In these CPs, the conformational and structural flexibilities can be effectively increased by lengthening the bridging ligand and addition of pendent methyl groups in the phosphine ligands, respectively, resulting in more obvious piezochromism. In addition, the XLCT/MLCT ratios are efficiently modulated by adjusting the flexibility of halogen electron cloud, which further affects the piezochromic property. Upon the combined effect of multiple flexibilities, a closely packed CP with a large wavelength shift (77 nm) and reversible piezochromism is found. [ABSTRACT FROM AUTHOR]

Phosphines bearing guanidine substituents at the backbone are attractive hybrid ligands that have not yet received adequate attention. This paper describes group 11 metal complexes of a guanidine-substituted triphenylphosphine, viz., N′′-[2-(diphenylphosphino)phenyl]-N,N′-diisopropylguanidine (1). Reactions of 1 with Cu(I) and Ag(I) precursors yielded the P,N-chelate complexes [M(1-κ2P,N)2]X, where M/X = Cu/BF4, Cu/Br, Ag/SbF6 and Ag/Br. Conversely, reacting 1 and the hydrochloride 1·HCl with [AuCl(SMe2)] produced the corresponding phosphine complexes [AuCl(1-κP)] and [AuCl(1H-κP)]Cl, which were further converted into [{μ(P,N)-1}2Au2][SbF6]2 and [AuCl(1H-κP)][SbF6], respectively, by reacting with Ag[SbF6]. These compounds and the bis-phosphine complex [Au(1-κP)2][SbF6] were studied as precatalysts in the Au-mediated cyclisation of N-propargylbenzamide and the addition of benzoic acid across terminal alkynes. Of the Au(I)-1 complexes studied, the complex [{μ(P,N)-1}2Au2][SbF6]2 was particularly attractive as a stable and well-defined, silver-free precatalyst, which can be conveniently activated in situ by the addition of a protic acid (either as an additive or a substrate). [ABSTRACT FROM AUTHOR]

The synthesis of novel phosphine palladium PEPPSI and dimer complexes bearing RuPhos, SPhos and XPhos phosphines is reported. The crystal structures of XPhos Pd PEPPSI with pyridine, SPhos Pd PEPPSI with 3-chloropyridine as throw-away ligands and the RuPhos palladium dimer were obtained and compared with previously reported congeners. The catalytic activity of these novel complexes was examined via a C–N coupling reaction involving 4-chloroanisole and morpholine. RuPhos complex 2b proved most active, leading to 97% yield with a low (0.2 mol%) catalyst loading, while phosphine palladium dimers showed significantly lower catalytic activity. However, the addition of 3-pentanone as an activator/stabilizer significantly improved the yields of phosphine dimers and PEPPSI complexes when the reactions were performed in THF. [ABSTRACT FROM AUTHOR]

The syntheses of the first B9‐connected carboranylphosphines (B9‐Phos) featuring two carboranyl moieties as well as access to B9‐Phos ligands with bulky electron‐donating substituents, previously deemed unattainable, is reported. The electrochemical properties of the B9‐Phos ligands were investigated, revealing the ability of the mesityl derivatives to form stabilized phosphoniumyl radical cations. The B9‐Phos ligands display an extremely electron‐releasing character surpassing that of alkyl phosphines and commonly used N‐heterocyclic carbenes. This is demonstrated by their very small Tolman electronic parameters (TEPs) as well as extremely low P−Se coupling constants. Cone angles and buried volumes attest to the high steric demand exerted by the (di)carboranyl phosphines. The dicarboranyl phosphine AuI complexes show superior catalytic performance in the hydroamination of alkynes compared to the monocarboranyl phosphine analogs. [ABSTRACT FROM AUTHOR]

As concentration of nitrous oxide (N2O) keeps growing steeply in the atmosphere, upgrading this anthropogenic greenhouse gas as a potential oxygen transfer agent constitutes a real challenge to limit global warming and ozone layer depletion. Decomposition of N2O is mainly described under highly energy‐consuming thermal activation, owing to its high stability and large activation barrier, making it kinetically inert. Herein, we demonstrate the controlled photocatalytic upgrading of N2O as an oxygen atom donor, releasing only dinitrogen (N2) as a benign co‐product. The doped Ag@TiO2 photocatalyst specifically activates N2O for controlled oxidation of phosphines avoiding mineralization, under mild conditions (room temperature, 1 atm, λ=365 nm), as a proof‐of‐concept of the valorization of N2O as an oxygen transfer agent. The catalytic system is active and selective in various organic solvents, as well as innovatively in water, depending on the phosphine structure. [ABSTRACT FROM AUTHOR]

A new series of cationic heterodinuclear complexes, [M1M2Cl2(meso‐dpmppp)(RNC)2]PF6 (M1=Ni, M2=Rh, R=tBu (1 a); M1=Pd, M2=Rh, R=tBu (2 a), Xyl (2 b); M1=Pt, M2=Rh, R=tBu (3 a), Xyl (3 b); M1=Pd, M2=Ir, R=tBu (4 a)), supported by a tetradentate phosphine ligand, meso‐Ph2PCH2P(Ph)(CH2)3P(Ph)CH2PPh2 (meso‐dpmppp), were synthesized by stepwise reactions of meso‐dpmppp with NiCl2 ⋅ 6H2O or MCl2(cod) (M=Pd, Pt), forming mononuclear metalloligands of [M1Cl2(meso‐dpmppp)], and with [M2Cl(cod)]2 (M2=Rh, Ir) and RNC (R=tBu, Xyl) in the presence of [NH4][PF6]. The related neutral PdRh complex, [PdRhCl3(meso‐dpmppp)(XylNC)] (5), was also prepared. The structures of 1–5 were determined by X‐ray analyses to contain two square planar d8 metal centers with face‐to‐face arrangement, where meso‐dpmppp supports M1 and M2 metal ions in cis/trans‐P,P coordination mode, combining cis‐{M1P2Cl2} and trans‐{M2P2(CNR)2} units. Complexes 1–4 showed an intence characteristic absorption around 422–464 nm derived from RhI→RNC MLCT transition (HOMO→LUMO+1), which are influenced by changing M1 (NiII, PdII, PtII) metal ions since HOMO composed of dσ* orbitals appreciably destabilized by changing M1 from Ni to Pd, and Pt. The electronic structures of 1 a–4 a were investigated on the basis of DFT calculations and NBO analyses to show weak but noticeable d8–d8 metallophilic interaction as empirical dispersion energy of 0.9–1.5 kcal/mol without M1–M2 covalent bonding interaction. In addition, 1–5 were utilized as catalysts for hydrosilylation of styrene, and the NiRh complex 1 a was found to show higher activity and chemo‐ and regioselectivity compared with 2–5. [ABSTRACT FROM AUTHOR]

In the synthesis of InP‐based quantum dots (QDs), the environmentally friendly carboxylic‐free phosphor precursor tris(dimethylamino)phosphine ((DMA)3P) has been frequently used to replace tris (trimethylsilyl)phosphine (TMS)3P, in order to prevent the InP cores from oxidation and avoid the dangerous etching with hydrofluoric acid. However, the InP‐based QDs synthesized with (DMA)3P still perform poorly in quantum dot light‐emitting diodes (QLEDs) due to oxidation by other carboxylic sources. In this work, based on the synthesis with (DMA)3P, ZnCl2 precursor instead of zinc carboxylate is used for shell growing, and oleylamine is used as solvent instead of oleic acid, so that there is no oxidizing agent such as carboxylic groups during the whole synthesis process. As a result, highly efficient InP/ZnSe/ZnSeS/ZnS QDs with gradient varying shells are obtained, whose full width at half‐maximum (≈41 nm) and photoluminescence quantum yield (≈96%) are narrowest and highest among the reported ones, respectively. The QLEDs based on InP QDs synthesized with (DMA)3P achieve breakthrough efficiency of 12.39%. Especially, high efficiency and high brightness are achieved at the same time. This work opens a new avenue in the synthesis of high‐quality and environmental friendly InP‐based QDs. [ABSTRACT FROM AUTHOR]

Organoruthenium pyrithione (1-hydroxypyridine-2-thione) complexes have been shown in our recent studies to be a promising family of compounds for development of new anticancer drugs. The complex [(η6-p-cymene)Ru(pyrithionato)(pta)]PF6 contains phosphine ligand pta (1,3,5-triaza-7-phosphaadamantane) as a functionality that improves the stability of the complex and its aqueous solubility. Here, we report our efforts to find pta alternatives and discover new structural elements to improve the biological properties of ruthenium anticancer drugs. The pta ligand was replaced by a selection of phosphine, phosphite, and arsine ligands to identify new functionalities, leading to improvement in inhibitory potency towards enzyme glutathione S-transferase. In addition, cytotoxicity in breast, bone, and colon cancers was investigated. [ABSTRACT FROM AUTHOR]

Three protocols that involve the cleavage of the Au−P bond in Au‐substituted phosphines (AuPhos) have been demonstrated, namely i) direct demetallation with a strong anionic base; ii) protonation followed by demetallation with a neutral base; iii) oxidation‐triggered metal migration. Specifically, direct demetallation of (CAAC)AuPPh2 (1 a) (CAAC=cyclic (alkyl)(amino)carbene) with KP(TMS)2 or LiC(N2)TMS yields (CAAC)AuPTMS2 (2) or (CAAC)AuC(N2)TMS (3), respectively. Treatment of (NHC)AuPPh2 (1 b) (NHC=N‐heterocyclic carbene) with HOTf followed by the corresponding neutral phosphine gives scarce examples of aurophosphonium salts [(NHC)AuPHAd2][OTf] (5) and [((NHC)Au)2PPh2][OTf] (6). Oxidation of 1 a or 1 b with Se affords LAuSeP(Se)Ph2 (L=CAAC, 7 a; NHC, 7 b). [ABSTRACT FROM AUTHOR]

The reactivity of alkynylphosphines with Lewis acidic boranes has been well established in recent years thanks to the advent of frustrated Lewis pairs (FLPs), often leading to a 1,1‐carboboration reaction and the formation of an intramolecular phosphinoborane FLP. Our group recently discovered that introduction of an ionizable group in the γ‐position of an alkynylphosphine result in an unexpected rearrangement reaction to yield zwitterionic allenic‐phosphonium borate products which are produced via a transient 3‐coordinate phosphonium allenylidene. Herein, we describe how substituent effects on the γ‐carbon impact this reactivity and explore how bis(alkynyl)phosphines behave under similar reaction conditions. [ABSTRACT FROM AUTHOR]

Cu(I) from tetrakis(acetonitrile)copper(I) hexafluorophosphate ([Cu(MeCN)4]PF6) was complexed with five structurally related phosphines containing N-heterocycles. The interactions between the resulting complexes and some N-nitrosamines were studied using X-ray crystallography as well as emission spectroscopy. Upon complexation, three phosphine ligands bridge two Cu(I) centers to give paddlewheel type structures that displayed a range of emission wavelengths spanning the visible region. N-Nitrosodimethylamine (NDMA) was shown to coordinate to one of the two copper centers in some of the paddlewheel complexes in the solid state and this interaction also quenches their emissions in solution. The influence of the weakly coordinating anion on crystal and spectroscopic properties of one of the paddlewheel complexes was also examined using tetrakis(acetonitrile)copper(I) perchlorate ([Cu (MeCN)4]ClO4) as an alternative Cu(I) source. Similarly, copper(II) perchlorate hexahydrate (Cu (ClO4)2·6H2O) was used for complexation to observe the impact of metal oxidation state on the two aforementioned properties. Lastly, the spectroscopic properties of the complex between Ph2P(1- Isoquinoline) and Cu(I) was shown to exhibit solvent dependence when the counterion is ClO4 -. These Cu(I) complexes are bench stable solids and may be useful materials for developing a fluorescence based detection method for N-nitrosamines. [ABSTRACT FROM AUTHOR]

A scalable synthetic route to both primary arylphosphines ArPH2 and aryldichlorophosphines ArPCl2 is reported. The C–P bond formation was performed in a highly regiospecific manner through electrophilic substitution of selected aromatic hydrocarbons (ArH) with phosphorus pentasulfide. The resultant perthiophosphonic anhydrides Ar2 P2 S4 were then reacted with LiAlH4 to give primary phosphines ArPH2. Subsequent reaction of ArPH2 with phosgene solution gives dichlorophosphines ArPCl2. Each reaction step requires minimum purification and uses commercially available and economical precursors. The scope of the reaction was shown to include alkoxy and phenoxy substituted benzenes as well as naphthalene and fluorene as starting materials. [ABSTRACT FROM AUTHOR]

A rare study into the catalytic hydrophosphination of allenes is reported. Employing an Fe(II) β-diketiminate pre-catalyst, the reaction of HPPh2 proceeds with a range of aryl- and alkylallenes. For arylallenes the E -vinyl product forms as the major species, while the 1,1-disubstituted alkene is formed in a larger ratio than the Z -vinyl product (e.g., 6:3:1 as E /1,1/ Z). The use of H2 PPh results in good yields of the 1,1-disubstituted alkene, where the resultant secondary phosphine product does not undergo further reaction. We postulate a catalytic cycle based on spectroscopic data. Employing an [Fe(salen)]2-µ-oxo pre-catalyst leads to phosphine dehydrocoupling rather than hydrophosphination. [ABSTRACT FROM AUTHOR]

We report herein on the phosphine-catalyzed Z -selective carbofluorination of alkynoates bearing an N-heteroarene unit, by using acyl fluorides as bifunctional reagents. This reaction proceeds through a pentacoordinate fluorophosphorane(V) intermediate, resulting in the formation of a C–F bond by a ligand coupling process. The Z -selectivity is attributed to the thermodynamic stabilization of a Z -isomer by orbital interactions between lone pair electrons of an N-heteroarene and the π* orbital of a carbonyl group. [ABSTRACT FROM AUTHOR]

A family of planar chiral indene-fused ferrocenes were prepared through an intramolecular asymmetric C–H arylation in excellent yields (up to 99%) with excellent enantioselectivities (up to 99% ee). They were thereafter successfully transformed to chiral ferrocenyl phosphines, featuring both planar and central chiralities, in good yields (up to 83%) and excellent diastereoselectivities (up to 99% de) through highly diastereoselective phosphination. This protocol offers a general method for planar and central chiral ferrocenyl phosphines. The potential applications of the newly developed ligands were demonstrated by a Pd-catalyzed enantioselective allylic alkylation reaction, in which high enantioselectivity (92% ee) and good yield (89%) were obtained. [ABSTRACT FROM AUTHOR]

Transformation of multifunctional materials with control over site-selectivity and chemical diversity remains challenging. Herein, we present a metal-free, one-pot strategy for the defluorophosphorylation of polyfluoroalkyl peroxides that enables expedient construction of structurally diverse phosphoryl-containing heterocyclic libraries. By judicious choice of reaction conditions, C3,4-diphosphoryl furans and C4-monophosphoryl furans can be easily accessed. In addition, synthetic derivatization of the obtained organophosphorus heteroarenes to value-added monodentate and bidentate phosphines has been demonstrated. Mechanistic studies revealed that regioselective defluorophosphorylation allows divergent product formation in two reaction modes. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

This paper provides insight into the various studies that have been carried out to date on liquid crystalline materials based on copper(I) complexes. Although the study of copper(I) complexes with respect to their liquid crystalline property is quite limited, metallomesogens prepared with different structural components and ligands from groups such as azamacrocycles, alkythiolates, ethers, isocyanides, phenanthroline, Schiff bases, pyrazolates, phosphines, biquinolines, and benzoylthioureas are reported and summarized in this review. A special section is dedicated to the discussion of emission properties of copper(I) metallomesogens. [ABSTRACT FROM AUTHOR]

A convenient synthesis of functionalized β-phosphorus-substituted tetraorganosilanes containing hydrolysis-resistant organosilicon moieties comprises radical addition of bis(trimethylsiloxy)phosphine to substituted vinyl- and divinylsilanes. The reaction proceeds regioselectively to form new silicon-containing ethyl phosphonites, the subsequent functionalization of which affords target different-structure tetraorganosilanes. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

The simplest diphosphene HPPH and isomeric diphosphinyldene PPH2 features prototype phosphorus‐phosphorus multiple bonding properties that have been of long‐standing interest in main‐group chemistry. Herein, we report the observation of cis‐HPPH, trans‐HPPH, and PPH2 among the respective laser photolysis products of phosphine (PH3) and diphosphine (P2H4) in solid N2‐ and Ar‐matrices at 10 K. The identification of these P2H2 isomers with matrix‐isolation IR and UV/Vis spectroscopy is supported by D‐isotope labeling and the quantum chemical calculations at the CCSD(T)‐F12a/cc‐pVTZ‐F12 level using configuration‐selective vibrational configuration interaction theory (VCI). Bonding analyses suggest that the two conformers of HPPH contain standard PP double bonds, whereas, PPH2 resembles P2 in having partial PP triple bond due to the H2P←P π bonding interaction. [ABSTRACT FROM AUTHOR]

We carried out trials on the commercial applications of nitrogen in different industrial structures, using phosphine-susceptible and -resistant populations of three stored product beetle species, the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), and the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Twelve different trials were conducted in total, five in chambers and seven in large silos in Greece, following different temperatures and exposure times. In most of our trials, complete mortality was recorded, with the exception of two silos in which survival was recorded for T. castaneum and O. surinamensis, while S. oryzae was classified as the most susceptible species. Moreover, low or no progeny production was recorded for most of the trials. Our results indicate that nitrogen, through the reduction in the oxygen level, could be used for the control of stored product insects that are resistant to phosphine, and can be further utilized in resistance management strategies. [ABSTRACT FROM AUTHOR]

Reaction of the divalent M(OTf)2 (M = Sn, Pb; OTf = CF3SO3) with soft phosphine and arsine ligands, L, where L = o-C6H4(ER2)2 (E = P, R = Me or Ph; E = As, R = Me), MeC(CH2ER2)3 (E = P, R = Ph; E = As, R = Me), PhP(CH2CH2PPh2)2 or P(CH2CH2PPh2)3, affords complexes of stoichiometry M(L)(OTf)2 as white powders, which have been characterised via elemental analysis, 1H, 19F{1H}, 31P{1H} and 119Sn NMR spectroscopy, with the expected 31P–119Sn and 31P–207Pb couplings clearly evident. The crystal structures of nine of these pnictine complexes are reported, in each case revealing retention of one or both OTf anions, which gives rise to a diverse range of coordination environments including monomers, as well as varying degrees of oligomerisation to form weakly associated (OTf-bridged) dimers, trimers and polymers. 19F{1H} NMR spectra indicate that the OTf is essentially anionic (dissociated) in solution. Anion metathesis of [M(OTf)2{MeC(CH2PPh2)3}] with Na[BArF] (BArF = B{3,5-(CF3)2C6H3}4) yields the corresponding [M{MeC(CH2PPh2)3}][BArF]2 salts, the crystal structures of all three (M = Ge, Sn, Pb) reveal pyramidal dications with discrete [BArF]− anions providing charge balance. Density functional theory (DFT) calculations on these [M{MeC(CH2PPh2)3}]2+ (M = Ge, Sn, Pb) dications using the B3LYP-D3 functional show the presence of a directional lone pair, which is a mixture of valence s and pz character, with the valence p-orbital character decreasing down group 14. Natural bond orbital (NBO) analysis also shows that the natural charge at the metal centre increases and the charge on the P centre decreases upon going down group 14. [ABSTRACT FROM AUTHOR]

Palladium‐catalyzed couplings of silicon enolates with aryl electrophiles are of great synthetic utility, but often limited to expensive bromide substrates. A comparative experimental study confirmed that none of the established ligand systems allows to couple inexpensive aryl chlorides with α‐trimethylsilyl alkylnitriles. In contrast, ylide functionalized phosphines (YPhos) led to encouraging results. A statistical model was developed that correlates the reaction yields with ligand features. It was employed to predict catalyst structures with superior performance. With this cheminformatics approach, YPhos ligands were tailored specifically to the demands of Hiyama couplings. The newly synthesized ligands displayed record‐setting activities, enabling the elusive coupling of aryl chlorides with α‐trimethylsilyl alkyl nitriles. The preparative utility of the catalyst system was demonstrated by the synthesis of pharmaceutically meaningful α‐aryl alkylnitriles, α‐arylcarbonyls and biaryls. [ABSTRACT FROM AUTHOR]

A direct electrochemical phosphine-mediated deoxygenative [3 + 2] cycloaddition strategy for oxazole synthesis is described, employing naturally abundant and inexpensive carboxylic acids as starting materials. This method is performed in a green and sustainable catalytic system, and avoids the use of transition metals and toxic oxidants. Good functional group tolerance, the success of gram-scale experiments and the late-stage modification of drug molecules greatly highlight the potential applicability of our method. Mechanistic studies suggest that an acyloxyphosphonium ion is generated as a key intermediate via anodic oxidation, followed by nucleophilic substitution and cycloaddition with isocyanide. [ABSTRACT FROM AUTHOR]