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New chiral BINOL‐based phosphate counterions have been synthesized, fully characterized, and employed in the enantioselective gold‐catalyzed dearomatization of β‐naphthols with allenamides. A range of densely functionalized C1‐allylated naphthalenones were realized under mild conditions and high levels of chemo‐, regio‐ and stereoselectivity (ee up to 95 %). [ABSTRACT FROM AUTHOR]

Ferrocene with its aromaticity and facile redox properties is an attractive moiety to be incorporated into functional moieties. Medicinal applications of ferrocene are well known and ferrocene itself shows cytotoxic and antianemic properties. In this article, we will describe the synthesis and the structure analysis of two pseudopeptides containing a ferrocene moiety as N‐terminal group. After purification, Fc‐l‐Phe‐d‐Oxd‐OBn [l‐Phel‐phenylalanine; d‐Oxd(4R,5S)‐4‐Methyl‐5‐carboxy‐oxazolidin‐2‐one] appears as bright brown solid that spontaneously forms brown needles. The X‐ray diffraction of the crystals shows the presence of strong π interactions between the ferrocenyl moiety and the phenyl rings, while no NH•••OC hydrogen bonds are formed. This result is confirmed by FT‐IR and 1H NMR analysis. In contrast, both FT‐IR and 1H NMR analysis suggest that Fc‐(l‐Phe‐d‐Oxd)2‐OBn forms a turn conformation stabilized by intramolecular NH•••OC hydrogen bonds in solution. Chiroptical spectroscopies (ECD and VCD) substantially confirmed the absence of a well‐defined folded structure. The presence of the Fc moiety is responsible for specific ECD signals, one of which displayed pronounced temperature dependence and is directly related with the helicity assumed by the Fc core. Solid‐state ECD spectra were recorded and rationalized on the basis of the X‐ray geometry and quantum‐mechanical calculations. [ABSTRACT FROM AUTHOR]

A novel gold(I)-catalyzed protocol for the synthesis of 4H-1,3-dioxin-3-ones is presented. The protocol exploits a metal induced cascade sequence involving a [3,3]-sigmatropic rearrangement followed by regioselective O-annulation reactions. A wide range of oxygen-based heterocyclic scaffolds (21 examples) were achieved in excellent yield (up to 80%) and a detailed computational investigation as well as deuterium-labelling investigations enabled all the plausible reaction pathways to be mapped and the rationalization of the recorded regioselectivity. [ABSTRACT FROM AUTHOR]

The TBD (1,3,5‐triazabicyclodec‐5‐ene) assisted three‐component carbonylation of pyridine‐2‐methanamines is documented by means of CO2 as a benign CO surrogate. The redox‐neutral methodology enables the realization of densely functionalized imidazo‐pyridinones in high yields (up to 93 %) and excellent chemoselectivity. Combined computational and experimental investigations revealed an unprecedented RCOCl/TBD concerted electrophilic activation of carbon dioxide. [ABSTRACT FROM AUTHOR]

The "self-adaptability" of galvanostatic electrolysis was shown to assist a multistage unprecedented chemo- and diastereoselective electrochemically promoted cyclodimerization of chalcones. The process, all involving the reductive events, delivered densely functionalized cyclopentanes featuring five contiguous stereocenters (25 examples, yields of up to 95%, dr values up to >20 : 1). Dedicated and combined experimental as well as electrochemical investigation revealed the key role of a dynamic kinetic resolution of the aldol intermediate for the reaction mechanism. [ABSTRACT FROM AUTHOR]

The first asymmetric organocatalytic strategy enabling access to both five- and six-membered -nitro-spirocarboxylic oxindoles containing up to six consecutive stereogenic centers is developed. [ABSTRACT FROM AUTHOR]

The [2+2]-cycloaddition between indoles and allenamide gives access to methylenecyclobutanes representing competent buildings block in organic synthesis which are especially attractive in future synthesis of indole based alkaloids. [ABSTRACT FROM AUTHOR]

The site-selective dearomatization of naphthols is realized in a straightforward manner through a gold(I)-catalyzed [3,3]-sigmatropic rearrangement/allene functionalization cascade sequence. The method employs readily available naphthylpropargyl ethers as starting materials. A range of densely functionalized dihydrofurylnaphthalen-2(1 H)-ones are obtained in high yields (up to 98 %) and extremely mild reaction conditions (reagent grade solvent, air, 10 minute reaction time). A complete theoretical elucidation of the reaction machinery is also proposed, providing a rationale for important issues such as regio- and chemoselectivity. [ABSTRACT FROM AUTHOR]

Metallodrugs represent a combination of multifunctionalities that are present concomitantly and can act differently on diverse biotargets. Their efficacy is often related to the lipophilic features exhibited both by long carbo-chains and the phosphine ligands. Three Ru(II) complexes containing hydroxy stearic acids (HSAs) were successfully synthesized in order to evaluate possible synergistic effects between the known antitumor activity of HSA bio-ligands and the metal center. HSAs were reacted with [Ru(H)2CO(PPh3)3] selectively affording O,O-carboxy bidentate complexes. The organometallic species were fully characterized spectroscopically using ESI-MS, IR, UV-Vis, and NMR techniques. The structure of the compound Ru-12-HSA was also determined using single crystal X-ray diffraction. The biological potency of ruthenium complexes (Ru-7-HSA, Ru-9-HSA, and Ru-12-HSA) was studied on human primary cell lines (HT29, HeLa, and IGROV1). To obtain detailed information about anticancer properties, tests for cytotoxicity, cell proliferation, and DNA damage were performed. The results demonstrate that the new ruthenium complexes, Ru-7-HSA and Ru-9-HSA, possess biological activity. Furthermore, we observed that the Ru-9-HSA complex shows increased antitumor activity on colon cancer cells, HT29. [ABSTRACT FROM AUTHOR]

The article titled "Front Cover: Structure-Based Design and in-Flow Synthesis of Aromatic Endoperoxides Acting as Oxygen Releasing Agents" in the European Journal of Organic Chemistry discusses a new method for synthesizing aromatic endoperoxides (EPOs) that can release oxygen to relieve hypoxia. Through computational calculations and crystallographic data, three novel EPOs were designed to bind and release singlet oxygen under green light irradiation, regenerating the parent compound. The authors, Marco Agnes, Adelaide Santagata, Daniele Veclani, Alessandro Venturini, Magda Monari, Paolo Dambruoso, and Ilse Manet, provide more information in their research article. [Extracted from the article]

The Boulton–Katritzky reaction represents one of the most popular and efficient strategies used to realize azole-into-azole conversions. For example, under different experimental conditions, it allows the rearrangement of Z -arylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazoles ( 1 ) into 2-aryl-4-benzoylamino-5-phenyl-2 H -1,2,3-triazoles ( 2 ) in very high yields. Moreover, we have recently realized this conversion also by UV-photostimulation. Now we have enlarged the scope of the reaction irradiating with visible or UV light an acetonitrile solution of some Z -arylhydrazones ( 1a – e ) in the presence of catalytic amounts of Ru(bpy) 2 Cl 2 . We have observed the unexpected formation of the 1-aryl-5-benzoylamino-3-phenyl-1,2,4-triazoles ( 3a – e ) eventually together with the expected 2a – d in high yields. [ABSTRACT FROM AUTHOR]

A new [Au(I)] catalyzed intramolecular hydrocarboxylation of allenes is presented as a valuable synthetic route to oxazino-indolones. The use of 3,5-(CF3)2–C6H3–ImPyAuSbF6 as the optimal catalyst (5 mol%) was necessary to guarantee (i) wide tolerance of functional groups, (ii) mild reaction conditions (r.t., 16 h), and (iii) high yields (up to 90%). Preliminary attempts towards an enantioselective version (81 : 19 er) are also documented by means of a new family of chiral C1-symmetric ImPyAuCl complexes. [ABSTRACT FROM AUTHOR]

A carboxylative Ni-catalyzed tandem C–C σ-bond activation of cyclobutanones followed by CO2-electrophilic trapping is documented as a direct route to synthetically valuable 3-indanone-1-acetic acids. The protocol shows an adequate functional group tolerance and useful chemical outcomes (yield up to 76%) when AlCl3 is adopted as an additive. Manipulations of the targeted cyclic scaffolds and a mechanistic proposal based on experimental evidence complete the investigation. [ABSTRACT FROM AUTHOR]

Abstract: In this paper a new family of imines [N,N′-bis(2-pyridylmethylidene)-1,2-(R,S)-cyclohexanediamine (ligand 1); N,N′-bis(2-pyridylmethylidene)-1,2-(R,S)-cyclohexanediamine (ligand 3)] and amines [N,N′-bis(2-pyridylmethylene)-1,2-(R,R + S,S)-cyclohexanediamine (ligand 2); N,N′-bis(2-pyridylmethylene)-1,2-(R,S)-cyclohexanediamine (ligand 4)] pyridine-based chiral ligands and their chiral nitrate Eu(III) complexes is presented. Combination of structural and spectroscopic evidences in the solid state, reveals that the Eu(III) ion environment is characterized by a low symmetry for all the complexes. The 5D0 → 7F0 Eu(III) emission intensity reflects the degree of distortion of the metal surroundings, that is higher in the case of cis isomer of amine-based complex. This new family of Eu(III) chiral complexes are promising candidates for applications in the sensing field as probes in solution of the nitrate anion and of chiral molecules. [Copyright &y& Elsevier]

Abstract: The recent booming of gold catalysis has demonstrated that unprecedented transformations can be realized in a highly selective manner. Moreover, due to the growing availability of chiral organic ligands, gold-catalysis can be considered as one of most dynamic hot spots in asymmetric synthesis. However, in this context, the use of non-activated olefinic C–C double bonds is still largely unexplored due to the intrinsic inertness of Ct to allenes and alkynes) in taking part in nucleophilic additions assisted by π-electrophilic activations. Allylic alcohols have been demonstrated to be feasible “surrogates” of non-activated alkenes for the enantioselective allylic alkylation of indoles catalyzed by chiral gold(I) complexes. In this investigation, a full account addressing efficiency and substrate scope of such a process is presented. [ABSTRACT FROM AUTHOR]

Abstract: A combined catalytic and crystallographic investigation on the effectiveness of chiral diamino-bithiophene (2) and the corresponding diimino molecules (1) as chiral ligands for Pd(II) catalyzed transformations is presented. In particular, a systematic X-ray characterization of the [Pd]-pre-catalytic species provided valuable rationales for the different behavior of the two classes of ligands, underlining the key role played by sterical as well as electronic factors in controlling the oxidative addition of the starting racemic allylcarbonate to the chiral Pd(0) intermediate. Moreover, the versatility of the synthetic strategy for the preparation of enantiopure oligothienyl systems allowed us to synthesize a new type of mixed thiophene/pyridine ligands (2d) that have been effectively employed in asymmetric allylic alkylations (AAA). [Copyright &y& Elsevier]

A dehydrogenative functionalization of styryl carbon‐carbon double bonds with triflamide is described via dual visible‐light photoredox/cobaloxime catalysis. A range of allylic triflamides (20 examples) were isolated in moderate to good yields (up to 88%) under stoichiometric acceptorless conditions. Dedicated labelling, as well as spectroscopic experiments, enabled to shed light on the concatenated photo‐ and chemo‐catalytic cycles. [ABSTRACT FROM AUTHOR]

A novel asymmetric nickel‐based procedure has been developed in which CO2 fixation is achieved as a second step of a truncated Heck coupling. For this, a new chiral ligand has been prepared and shown to achieve enantiomeric excesses up to 99 %. The overall process efficiently furnishes chiral 2,3‐dihydrobenzofuran‐3‐ylacetic acids, an important class of bioactive products, from easy to prepare starting materials. A combined experimental and computational effort revealed the key steps of the catalytic cycle and suggested the unexpected participation of Ni(I) species in the coupling event. [ABSTRACT FROM AUTHOR]

The site‐selective allylative and allenylative dearomatization of indoles with alcohols was performed under carbocatalytic regime in the presence of graphene oxide (GO, 10 wt % loading) as the promoter. Metal‐free conditions, absence of stoichiometric additive, environmentally friendly conditions (H2O/CH3CN, 55 °C, 6 h), broad substrate scope (33 examples, yield up to 92 %) and excellent site‐ and stereoselectivity characterize the present methodology. Moreover, a covalent activation model exerted by GO functionalities was corroborated by spectroscopic, experimental and computational evidences. Recovering and regeneration of the GO catalyst through simple acidic treatment was also documented. [ABSTRACT FROM AUTHOR]

The site-selective thio-allylation of electron-deficient 1,2-dienes is documented under scandium catalysis. The methodology enables the realization of α-β unsaturated, β-thio, γ-allyl carboxylic acid derivatives via a one-pot Lewis acid promoted Michael addition/[3,3]-sigmatropic rearrangement sequence (20 examples) in high yields (up to 95%). Full rationalization of the reaction mechanism and stereochemical outcome is provided via DFT simulations. [ABSTRACT FROM AUTHOR]

Electrophilic amination of diastereomeric 4‐methoxycarbonyl pyrrolidin‐2‐ones allowed to prepare both diastereomers of an amino acid bearing a quaternary chiral center, a key intermediate to antibiotic 8‐methoxyquinolone carboxylic acid. Within this synthesis, novel atropisomers, exceedingly stable at room temperature, were isolated and characterized, which were subsequently converted into the desired products by a novel reductive N–N bond cleavage reaction. Within the synthesis of both the diastereomers of an amino acid bearing a quaternary chiral center, novel N–N atropisomers, which are exceedingly stable at room temperature, were isolated and characterized, and subsequently converted into the desired products by a novel reductive N–N bond cleavage reaction. [ABSTRACT FROM AUTHOR]

Different synthetic procedures lead to different coordination polymers (CPs) based either on the trinuclear triangular [Cu 3 ( μ 3 -OH)( μ -pz) 3 ] 2+ or on the mononuclear [Cu(Hpz) 3 ] 2+ (Hpz = pyrazole) secondary building units (SBUs), bridged by the flexible glutarate (Glu) dianion. The mononuclear complex [Cu(HGlu) 2 (Hpz) 4 ] was also obtained as byproduct. One of the CPs based on the trinuclear SBU displays a relevant porosity due to three intersecting channels, accounting for about 40% of the solvent accessible void space. [ABSTRACT FROM AUTHOR]

The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of O-alkylation, but a polar ones in the case of classic C-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards O-alkylation. Further support of this was obtained by diffractometric analysis of four distinct bis(heteroaryl)ketones. Keywords: bis(2-benzothiazolyl)ketone; Grignard reagents; vinylmagnesium bromide; C-alkylation; O-alkylation Abstract: The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of O-alkylation, but a polar ones in the case of classic C-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards O-alkylation. Further support of this was obtained by diffractometric analysis of four distinct bis(heteroaryl)ketones. [ABSTRACT FROM AUTHOR]

The use of a new copper(I) coordination polymer (CP) as additive in transparent composite films of 190 nm of thickness for ultraviolet (UV) shielding is presented. The luminescent 1-D Cu(I) CP was easily synthesized through a self-assembly process between Cu(I) iodide and 2,6-bis(1H-benzotriazol-1-ylmethyl)pyridine (L). The CP, [Cu2(μ − I)2(μ − L)2]n, was structurally characterized by infrared, UV–visible diffuse reflectance and photoluminescence spectroscopy, elemental and thermogravimetric analyses, single-crystal and powder X-ray diffraction, and relativistic density functional theory calculations. The CP was dispersed and immobilized into a polymeric matrix in the presence of Sudan I, yielding a composite material that exhibits a reduction of 49% of the UV transmittance at 350 nm. Thus, the use of a new Cu(I) CP in polymeric composite films appears as a novel approach toward ultrathin and transparent UV shielding films, which have potential applications as protection layers of paints and coatings that tend to degrade when exposed to UV radiation. [ABSTRACT FROM AUTHOR]

The azo-coupling reactions between 4-nitrobenzenediazonium tetrafluoroborate and a series of benzene derivatives bearing at least one electron-donating hydroxy or methoxy substituent have been studied. Depending on the nucleophile and its relative ratio with the diazonium salt, it was possible to obtain mono- and disubstituted products as well as a trisubstituted product for phloroglucinol. The reactions between 3,5-diaminoanisole or 3,5-diaminophenol derivatives and 2 equiv. of diazonium salt gave the monosubstituted product in the first case and a diadduct in the second case; X-ray diffraction analysis revealed a highly symmetric structure for the latter. The different behaviors of hydroxy- and methoxy-substituted compounds was particularly evident for phloroglucinol and 1,3,5-trimethoxybenzene and may be rationalized on the basis of the different electronic effects of the substituents. The propensities of the aromatic rings to undergo H/D exchange reactions were investigated for a series of substrates, and a comparison of the results obtained provided new insights into this phenomenon and permitted a better explanation of the findings reported here; a new particular interaction competes with the formation of a proton–phloroglucinol σ complex. [ABSTRACT FROM AUTHOR]

The reaction of some saturated and unsaturated aliphatic copper(II) monocarboxylates, Cu(RCOO) 2 [R = C 6 H 5 CH 2 (phenylacetate, Phac), CH 2 CHCH 2 (vinylacetate, Vnac), C 6 H 5 CH CH (3- trans -phenylacrylate, Phacr), C 6 H 5 (CH 2 ) 2 (3-phenylpropionate, Phpr), c -C 6 H 11 ( ciclo –hexylcarboxylate, c -Hexc), CH 3 (CH 2 ) 10 (laurate, Lau), CH 3 (CH 2 ) 12 (myristate, Myr), (CH 3 ) 3 C (pivalate, Piv)] with pyrazole (Hpz) and water in protic solvents, yielded trinuclear triangular derivatives based on the [Cu 3 ( μ 3 -OH)( μ -pz) 3 ] fragment whose double positive charge is balanced by two coordinated carboxylate ions, actually [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Phac) 2 ], 1 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Vnac) 2 (Hpz)], 2 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Phacr) 2 ], 3 , [{Cu 3 ( μ 3 -OH)( μ -pz) 3 (Phpr) 2 (Hpz)}{Cu 3 ( μ 3 -OH)( μ -pz) 3 (Phpr) 2 (Hpz)(H 2 O)}]· x H 2 O· y MeOH, 4 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 ( c -Hexc) 2 ], 5 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Lau) 2 ], 6 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Myr) 2 ], 7 , [Cu 3 ( μ 3 -OH)( μ -pz) 3 (Piv) 2 (HPz)(HPiv) 2 ], 8 . This behavior is consistent with some previously observed features and evidences that the basicity of carboxylate ions is the key for the deprotonation of Hpz and water, leading to the formation of pz − and OH − ions, which are determinant for the self-assembly of the trinuclear triangular species. Single crystal XRD determinations evidenced that in compounds 1 , 2 and 5 the trinuclear moieties further self-assemble generating monodimensional coordination polymers or, in one case (compound 4 ), a dodecanuclear discrete assembly. [ABSTRACT FROM AUTHOR]

A series of dinuclear iron(III)I complexes supported by thioether-triphenolate ligands have been prepared to attain highly Lewis acidic catalysts. In combination with tetrabutylammonium bromide (TBAB) they are highly active catalysts in the synthesis of cyclic organic carbonates through the coupling of carbon dioxide to epoxides with the highest initial turnover frequencies reported to date for the conversion of propylene oxide to propylene carbonate for iron-based catalysts (5200 h−1; 120 °C, 2 MPa, 1 h). In particular, these complexes are shown to be highly selective catalysts for the coupling of carbon dioxide to internal oxiranes affording the corresponding cyclic carbonates in good yield and with retention of the initial stereochemical configuration. A density functional theory (DFT) investigation provides a rational for the relative high activity found for these Fe(III) complexes, showing the fundamental role of the hemilabile sulfur atom in the ligand skeleton to promote reactivity. Notably, in spite of the dinuclear nature of the catalyst precursor only one metal center is involved in the catalytic cycle. [ABSTRACT FROM AUTHOR]

A platform is described for the first time for the facile synthesis of oligo- and polythiophene-S-oxides and the corresponding -S,S-dioxides in short times, mild conditions, high yields. Employing ultrasound assistance, brominated thiophenes are selectively mono- or dioxygenated at room temperature. These building blocks are then combined with metalated thiophenes via microwave-assisted cross-coupling reactions through a 'Lego-like' strategy to afford unprecedented oligo/polythiophene-S-oxides and mixed -S-oxides/-S,S-dioxides. It is demonstrated that depending on the number, type, and sequence alternation of nonoxygenated, monooxygenated, and dioxygenated thiophene units a very wide property-function tuning can be achieved spanning from frontier orbital energies and energy gaps, to charge transport characteristics and supramolecular H-bonding interactions with specific proteins inside live cells. [ABSTRACT FROM AUTHOR]

The site-selective α-allylic alkylation of enones with alcohols via gold-triggered formation of nucleophilic allenoates by means of [3,3]-sigmatropic rearrangements of propargylic carboxylates is reported. A range of α-alkylated enones is obtained in high yields in the presence of the gold complex [JohnPhosAu(ACN)]SbF6 (2 mol%) as the promoting agent. Examples of allylation/Friedel-Crafts alkylation sequences are also provided, delivering densely functionalized dihydroindenes and dihydrobenzo[7]annulenes in a one-pot procedure in moderate yields. The role of the Brønsted acidity (i.e., pivalic acid) delivered during the reaction course in assisting the formation of carbocationic intermediates is documented. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of twenty new pentamethylcyclopentadienyl-rhodium and iridium complexes containing N^N and N^O-chelating chloroquine analogue ligands are described. The in vitro antimalarial activity of the new ligands as well as the complexes was evaluated against the chloroquine sensitive (CQS) NF54 and the chloroquine resistant (CQR) Dd2 strains of Plasmodium falciparum. The antimalarial activity was found to be good to moderate; although all complexes are less active than artesunate, some of the ligands and complexes showed better activity than chloroquine (CQ). In particular, rhodium complexes were found to be considerably more active than iridium complexes against the CQS NF54 strain. Salicylaldimine Schiff base ligands having electron-withdrawing groups (F, Cl, Br, I and NO2) in para position of the salicyl moiety and their rhodium complexes showed good antiplasmodial activity against both the CQS-NF54 and the CQR-Dd2 strains. The crystal structures of (η5-pentamethylcyclopentadienyl){N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethyl)ethane-1,2-diamine)} chlororhodium(iii) chloride and (η5-pentamethylcyclopentadienyl){(4-chloro-2-(((2-((7-chloroquinolin-4-yl)amino)ethyl)imino)methyl)phenolate)}chlororhodium(iii) chloride are reported. The crystallization of the amino-pyridyl complex (η5-pentamethylcyclopentadienyl){(N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethyl)ethane-1,2-diamine)}chloroiridium(iii) chloride in acetone resulted in the formation of the imino-pyridyl derivative (η5-pentamethylcyclopentadienyl){(N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethylene)ethane-1,2-diamine)}chloroiridium(iii) chloride, the crystal structure of which is also reported. [ABSTRACT FROM AUTHOR]

Alkynyl(triphenylphosphine)gold(i) complexes carrying variously substituted propargylic amines have been synthesized and fully characterized in solution and solid state. High levels of toxicity (i.e. micromolar range) were recognized for a series of cancer cell lines with particular emphasis on HT29, IGROV1, HL60 and I407. In particular the lead compound 3ab was identified as the most active compound in all cell lines (IC50: 1.7–7.9 μM). [ABSTRACT FROM AUTHOR]

The gold-catalyzed synthesis of methylidene 2,3-cyclobutane-indoles is documented through a combined experimental/computational investigation. Besides optimizing the racemic synthesis of the tricyclic indole compounds, the enantioselective variant is presented to its full extent. In particular, the scope of the reaction encompasses both aryloxyallenes and allenamides as electrophilic partners providing high yields and excellent stereochemical controls in the desired cycloadducts. The computational (DFT) investigation has fully elucidated the reaction mechanism providing clear evidence for a two-step reaction. Two parallel reaction pathways explain the regioisomeric products obtained under kinetic and thermodynamic conditions. In both cases, the dearomative CC bond-forming event turned out to be the rate-determining step. [ABSTRACT FROM AUTHOR]

Ten rhenium carbonyl complexes-[Re(H)(CO)( 1a)], [Re(µ-H)(CO)( 1a)], [Re(CO)( 2a)], [Re(CO)( 2a)], [Re(CO)( 2b)], [{Re(CO)}( 2b)], [Re(CO)( 2b)], [Re(CO)( 1b)], [Re(µ-H)(CO)( 2b)] and [Re(µ-H)(CO)( 2b)]-containing different bidentate chiral phosphine ligands of the Josiphos ( 1a, 1b) and Walphos ( 2a, 2b) families have been synthesized and fully characterized ( 1a: ( R)-1-{( S)-2-[Bis[3,5-bis(trifluoromethyl)phenyl]phosphino]ferrocenyl}ethyldi(3,5-xylyl)phosphine, 1b: ( R)-1-{( S)-2-[Di(2-furyl)phosphino]ferrocenyl}ethyldi-tert-butylphosphine, 2a: ( R)-1-{( R)-2-[2-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]phenyl]ferrocenyl}ethylbis[3,5-bis(trifluoromethyl)phenyl]phosphine and 2b: ( R)-1-{( R)-2-[2-(Diphenylphosphino)phenyl]ferrocenyl}ethyldicyclohexylphosphine). The phosphine-substituted clusters were tested for hydrogenation of tiglic acid [ trans-2-methyl-2-butenoic acid]. The catalytic reactions gave reasonable conversion rates (15-88 %) under relatively mild conditions but relatively moderate enantiomeric excesses (8-57 %) were observed. The crystal structures of [ReH(CO)( 1a)], [Re(CO)( 2a)], [{Re(CO)}( 2b)] and [Re(µ-H)(CO)( 2b)] are presented. [ABSTRACT FROM AUTHOR]

The highly enantioselective synthesis of densely functionalized 2,3-indoline-cyclobutanes by means of chiral gold catalysis is presented. Intermolecular formal [2+2]-cycloaddition reactions between substituted indoles and allenamides enabled direct access to methylenecyclobutane-fused indolines, featuring two consecutive quaternary stereogenic centers with excellent stereochemical control (dr ＞ 20 : 1, ee up to 99%). [ABSTRACT FROM AUTHOR]

New organoruthenium [(η 6 -arene)Ru II (L)Cl]Cl ( 1 : arene = p -cymene, L = L 1 ; 2 : arene = p -cymene, L = L 2 ; 3 : arene = benzene, L = L 1 ; 4 : arene = benzene; L = L 2 ; L 1 = bis(3,5-dimethylpyrazolyl)parabenzoic acid, L 2 = bis(3,5-dimethylpyrazolyl)metabenzoic acid) have been synthesized and characterized by analytical and spectroscopic methods. The molecular structure of [(η 6 - p -cymene)RuCl(L 1 )]Cl ( 1 ) was determined by single crystal X-ray diffraction studies. Preliminary in vitro binding studies of 1 – 4 with CT DNA were carried out by employing various biophysical techniques which revealed their avid DNA binding via non-covalent binding mode viz; partial intercalation of the η 6 -arene group as well as electrostatic surface interaction through one oxygen atom of the phosphate backbone of the DNA helix; however, complexes 1 and 3 display higher binding propensity in comparison to 2 and 4 , as quantified by K b . The interaction was further analysed by HPLC technique. The results of the cleavage experiments of pBR322 DNA with 1 and 3 displayed significantly good cleavage at 20–40 μM, following the oxidative pathway. These findings have revealed that the hydrophobic arene, and the chloride leaving group have important roles in the novel mechanism of recognition of DNA by (η 6 -arene)ruthenium(II) complexes, and will aid the design of more effective anticancer complexes, as well as new site-specific DNA reagents. Furthermore, the anticancer activity of the complexes 1 and 3 on 15 cell lines of different histological origin has been studied. It has been observed that 1 exhibits higher cytotoxicity than 3 , and the cells undergo apoptotic cell death. [ABSTRACT FROM AUTHOR]