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The geometrical control of atom transfer radical addition (ATRA) reactions to alkynes poses significant challenges. Herein, we present a uniform solution by developing a stereodivergent synthetic method for both isomers of the resulting alkene products, starting from the same materials. The synthesis of the thermodynamically more stable isomer utilizes the strategy of uphill catalysis while the accumulation of the less stable isomer is facilitated by a manganese-catalyzed iodo-abstraction/radical rebound process, taking advantage of its reversibility. Various substituted alkyl iodides can be used to provide easy access to both isomers of iodoalkene products with valuable functional groups such as CF3, CF2H, CN, ester, or amide at the allylic position. [ABSTRACT FROM AUTHOR]

Direct dithiolation of alkenes with thiols has been rarely reported. Herein, a simple cobalt-catalyzed aerobic approach has been developed to realize this transformation. With the aid of HFIP, diverse vicinal dithioethers including symmetric and unsymmetric ones could be obtained from readily available substrates. Gram-scale synthesis and late-stage modification of complex molecules highlight the practicability of this approach. [ABSTRACT FROM AUTHOR]

The iridium-catalysed enantioselective [3+2] annulation of ortho-ketoarylboron compounds with conjugated dienes proceeded to give chiral indanol derivatives bearing an all-carbon quaternary stereogenic center in high yields with high enantioselectivity. Chiral phosphoramidite–olefin ligands were effective for the high reactivity and enantioselectivity. [ABSTRACT FROM AUTHOR]

Two CoII-coordination polymers were controllably obtained by the solvothermal reaction of C3 symmetric 5-bromo-1,3-benzenedicarboxylic acid (Br-1,3-H2BDC), 4,4′,4′′-(2,4,6-trimethylbenzene-1,3,5-triyl)tripyridine (4-TMTBT) ligand, and CoII salts. Co-CP-1 displayed a 3D net based on a mononuclear CoII center linked by Br-1,3-BDC2− and 4-TMTBT mixed ligands. Co-CP-2 featured a 3D network based on a trinuclear Co3(μ3-OH)(HCOO)(COO)4 unit and Br-1,3-BDC2− and 4-TMTBT ligands, which could be regarded as a new (3,7)-connected topology net. Interestingly, the two Co-CPs showed good catalytic activities for the alkene oxyalkylation reaction. In particular, Co-CP-2 exhibited higher catalytic performance and could be recycled at least for four cycles without loss of activity and structural integrity. [ABSTRACT FROM AUTHOR]

C(sp3) centers adjacent to (hetero) aryl groups are widely present in physiologically active molecules. Metal‐hydride‐catalyzed hydroalkylation of alkenes represents an efficient means of forging C(sp3)−C(sp3) bonds, boasting advantages as a wide source of substrates, mild reaction conditions, and facile selectivity manipulation. Nevertheless, the hydroalkylation of vinylarenes encounters constraints in terms of substrate scope, necessitating the employment of activated alkyl halides or alkenes containing chelating groups, remains a challenge. In this context, we report a general nickel‐hydride‐catalyzed hydroalkylation protocol for vinylarenes. Remarkably, this system enables α‐selective hydroalkylation of both aryl and heteroaryl alkenes under an extra ligand‐free condition, demonstrating excellent coupling efficiency and selectivity. Furthermore, through the incorporation of chiral bisoxazoline ligands, we have achieved regio‐ and enantioselective hydroalkylation of vinylpyrroles, thereby facilitating the synthesis of α‐branched alkylated pyrrole derivatives. [ABSTRACT FROM AUTHOR]

Given the pivotal role of β‐(het)arylethylamine moiety in bioactive molecules, the direct amino(het)arylation of alkenes occupies a privileged position in the construction of (het)arylethylamine derivatives. Herein we devise chiral sulfoximines as novel bifunctional reagents which exhibit remarkable efficiency in the challenging asymmetric alkene aminohetarylation reaction, particularly in terms of reactivity and stereo‐control. The chiral reagents can be conveniently accessed in gram scale, and efficiently generate N‐centered radicals under mild photochemical conditions. The transformation proceeds through enantioselective 1,4‐hetaryl migration, ensuring precise chirality transfer from sulfur‐ to carbon‐centers, rendering wide applicability to both aromatic and aliphatic alkenes. Furthermore, the method is straightforward to operate and does not require transition metals or photosensitizers, making it an attractive and practical option. [ABSTRACT FROM AUTHOR]

Two recent high‐profile publications reported the formation of Heck‐type arylated alkenes catalysed by MeDalPhosAuCl/AgOTf (J. Am. Chem. Soc. 2023, 145, 8810) and their cyclisation to tetralines (Angew. Chem. Int. Ed. 2023, e202312786). It was claimed that these were the first demonstrations in gold catalysis of alkene insertion into Au‐aryl bonds, β‐H elimination and chain‐walking by Au−H dications. We show here that in fact this chemistry is a two‐stage process. Only the first step, the production of an alkyl triflate ester as the primary organic product by the well‐known alkene heteroarylation sequence, involves gold. The subsequent formation of Heck‐type olefins and their cyclisation to tetralines represent classical H+‐triggered carbocationic chemistry. These steps proceed in the absence of gold with identical results. Literature claims of new gold reactivity such as chain walking by the putative [LAuH]2+ dication have no basis in fact. [ABSTRACT FROM AUTHOR]

Comprehensive Summary A copper‐catalyzed cyanation/diarylmethylation of formamides has been developed for the synthesis of α‐cyano functionalized tetra‐substituted olefins by utilizing para‐quinone methides (p‐QMs) and trimethylcyanosilane as functionalization sources. Various kinds of p‐QMs and formamides are well tolerated, delivering the desired products with 72%—94% yields, demonstrating broad functional group tolerance. Notably, the reaction does not require noble metals and proceeds regioselectively under mild conditions. Based on step‐by‐step control experiments, Hammett studies and DFT calculation, a plausible mechanism is proposed. [ABSTRACT FROM AUTHOR]

Reaction of neutral olefin complexes of ruthenium and molybdenum with GaTMP (TMP = 2,2,6,6-tetramethylpiperidinyl) by substitution leads to the formation of respective five- and six-coordinated homoleptic products. [Ru(GaTMP)5] (1) and [Mo(GaTMP)6] (2) were isolated and characterized. Core structure geometries were analyzed using continuous shape measure, and the complexes were subjected to DFT calculations unveiling competing π-interactions between the transition metal center and the amido substituent with the unoccupied pπ orbitals of the gallium. [ABSTRACT FROM AUTHOR]

Porphyrins belong to a peculiar class of natural molecules involved in many different biological processes of paramount importance, from photosynthesis in green plants, to the oxygen binding and transportation in breathing and to the oxidation reactions catalyzed by the enzymatic family of cytochromes P450. This versatility is due to the tight structure/properties relationship of these macrocycles. Many different synthetic strategies have been used to modify the porphyrin core by connecting electro- and photo-active moieties in both meso- and beta-pyrrole positions. Among them all, C–C bond formation still remains one of the most useful approaches to ensure fine control over the chemical–physics properties of porphyrins. In this work we successfully tested the catalytic system Pd(dba)2/AsPh3 in the Heck cross-coupling reaction between β-monobrominated tetraphenylporphyrin and ferrocenyl-alkene derivatives, avoiding the use of excess alkene and Ni(II) or Zn(II) porphyrinate complexes. The preferential formation of the alpha- versus trans-isomer was observed when vinylferrocene was used as the starting alkene, compared to styrene and 4-ferrocenylstyrene, either at lower (60 °C) or higher (90 °C) reaction temperature. Subsequent electrochemical and photochemical studies on ferrocene–porphyrin dyads pointed out the importance of the type of β-C–C bond between the two chromophores in modulating/affecting the electron-transfer processes. Such studies can be useful for the realization of highly sensible fluorescent-redox switches or even in the development of highly efficient ferrocene/porphyrin-based chemodynamic therapy agents. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first catalytic asymmetric total synthesis of (+)‐propolisbenzofuran B, enabled by a highly enantioselective rhodium‐catalyzed hydrogenation of a tetrasubstituted olefin, was described. Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)‐mediated regioselective benzofuran formation and Dieckmann condensation, as well as C‐H oxidations, involving a visible light‐induced Fe(III)‐catalyzed benzylic C(sp3)‐H oxidation. Additionally, the absolute configuration was confirmed by X‐ray analysis of a carbonate intermediate. [ABSTRACT FROM AUTHOR]

The single-sited metallocene catalyst has attracted significant attention due to its high activity and application in olefin polymerization industry. In this work, we introduced a strategy of in situ modification of metallocene catalyst with pyrene through π–π stacking to study the effect in olefin polymerization. After activated by MMAO, the pyrene-modified metallocene catalyst exhibited high activities (up to 1333 kg mol−1 h−1) in ethylene polymerization, which was 1.9 times higher than that of the pyrene free catalyst system. This could be because the electron-donating ability of cyclopentene to the transition metal was enhanced through π–π interaction of pyrene with cyclopentene. The copolymerization of ethylene and 1-hexene was also studied. The pyrene-modified metallocene catalyst system performs with higher activity in the copolymerization with a lower monomer incorporation ratio. Density functional theory (DFT) calculations indicated the formation of π–π interaction between the Zr center with pyrene molecule leading to the increase in steric hindrance and electron density. [ABSTRACT FROM AUTHOR]

The trans‐addition of intermetallic σ‐bonds (E−E′; E E'=Si, B, Se, P, Sn, etc.) across alkynes has emerged as an exceptionally atom‐economical means of constructing multi‐substituted alkenes, which readily transform into densely functionalized and biologically active compounds. Compared to the widely studied cis‐E−E' additions, trans‐E−E' additions remain a more challenging and underdeveloped area. In this article, recent advances in trans‐E−E' additions are summarized, encompassing various interelement compounds such as Si−Si, B−B, Si−B, P−B, Se−B, and B−Sn. We aim to provide a deeper understanding of trans‐E−E' additions and facilitate the further development of synthetic methodologies and applications of vicinally trans‐bismetallated alkenes. [ABSTRACT FROM AUTHOR]

The α‐arylated tetrahydrofurans, commonly found in biologically active molecules, exhibit diverse biological activities and pharmacological effects. The functionalization of 2,3‐dihydrofuran offers a potential route for the synthesis of substituted tetrahydrofurans. Nevertheless, the development of earth‐abundant metal‐catalyzed regioselective hydrofunctionalization of 2,3‐dihydrofuran for the synthesis of substituted tetrahydrofurans remains to be pursued. Herein, we report a cobalt‐catalyzed hydroarylation of 2,3‐dihydrofuran, which serves as the first example of cobalt hydride‐catalyzed alkene hydroarylation. This reaction provides an efficient method for the synthesis of α‐arylated tetrahydrofurans with high reaction efficiency, exclusive α‐arylation selectivity, and remarkable functional group compatibility. [ABSTRACT FROM AUTHOR]

We recently reported the gold‐catalyzed Heck and chain‐walking reactions, which utilize migratory insertion, β‐hydride elimination steps in a catalytic fashion. Budzelaar et al. in their correspondence state that these reactions proceed through gold‐catalyzed alkene heteroarylation followed by acid‐mediated elimination and cyclization sequence. In response to this correspondence, we have conducted some experiments which convinced us that the product formation solely can not be rationalized based on hetero‐arylation of alkenes under ligand‐enabled Au(I)/Au(III) catalysis. [ABSTRACT FROM AUTHOR]

A zirconocene dichloride‐catalyzed alkene hydrosilylation is reported that can be applied to non‐activated and conjugated terminal and internal alkenes. It involves a catalytic Zr‐walk process and leads to a selective conversion to the linear product. Lithium methoxide serves as mild catalyst activating agent, which significantly increases the applicability and operational simplicity in comparison to earlier zirconium(II)‐based protocols. Supported by additional experiments and calculations, a mechanism via zirconium(IV) intermediates is proposed. Due to the benign nature and ready‐availability of the zirconium catalyst, the reaction is an attractive alternative to established alkene hydrosilylation methods. [ABSTRACT FROM AUTHOR]

A cobalt‐catalyzed intramolecular Markovnikov hydroalkoxycarbonylation and hydroaminocarbonylation of unactivated alkenes has been developed, enabling highly chemo‐ and regioselective synthesis of α‐alkylated γ‐lactones and α‐alkylated γ‐lactams in good yields. The mild reaction conditions allow use of mono‐, di‐ and trisubstituted alkenes bearing a variety of functional groups. Preliminary mechanistic studies suggest the reaction proceeds through a CO‐mediated hydrogen atom transfer (HAT) and radical‐polar crossover (RPC) process, in which a cationic acylcobalt(IV) complex is proposed as the key intermediate. [ABSTRACT FROM AUTHOR]

A bisphosphirane‐fused anthracene (5) was prepared by treatment of a sterically encumbered amino phosphorus dichloride (3) with MgA ⋅ THF3 (A=anthracene). X‐ray diffraction analysis revealed a pentacyclic framework consisting of 5 with two phosphirane rings fused to the anthracene in a trans‐fashion. Compound 5 has been shown to be an efficient phosphinidene synthon, readily liberating two transient phosphinidene units for subsequent downstream bond activation via the reductive elimination of anthracene under mild conditions. The formal oxidative addition of H2 and E−H (E=Si, N, P) bonds by the liberated phosphinidene provided diphosphine and substituted phosphines. Furthermore, phosphinidene transfer to alkenes and alkynes smoothly yielded the corresponding phosphiranes and phosphirenes. The mechanism of the H2 activation by 5 was investigated by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The first catalytic asymmetric total synthesis of (+)‐propolisbenzofuran B, enabled by a highly enantioselective rhodium‐catalyzed hydrogenation of a tetrasubstituted olefin, was described. Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)‐mediated regioselective benzofuran formation and Dieckmann condensation, as well as C‐H oxidations, involving a visible light‐induced Fe(III)‐catalyzed benzylic C(sp3)‐H oxidation. Additionally, the absolute configuration was confirmed by X‐ray analysis of a carbonate intermediate. [ABSTRACT FROM AUTHOR]

Electronically mismatched Diels−Alder reaction between two electron-deficient components is synthetically useful and yet underdeveloped under thermal conditions. Herein, a photoinduced formal [4 + 2] cycloaddition of enone with a variety of electron-deficient dienes is described. Key to the success of this stepwise methodology relies on a C − C bond cleavage/rearrangement of the cyclobutane based overbred intermediate via diversified mechanistic pathways. Based on this annulation method, total synthesis of lucidumone is achieved in nine steps. Electronically mismatched Diels−Alder reaction between two electron-deficient components is synthetically useful and yet underdeveloped. Herein, a photoinduced formal [4 + 2] cycloaddition of enone with a variety of electron-deficient dienes is described. [ABSTRACT FROM AUTHOR]

The difunctionalization of alkenes represents a powerful tool to incorporate two functional groups into the alkene bones for increasing molecular complexity and has been widely utilizations in chemical synthesis. Upon the catalysis of the green, sustainable, mild photo‐/electrochemistry technologies, much attentions have been attracted to the development of new tactics for the transformations of the important alkene and alkane feedstocks driven by C−H radical functionalization. Herein, we summarize recent advances in the photo‐/electrocatalytic difunctionalization of alkenes enabled by C−H radical functionalization. We detailedly discuss the substrate scope and the mechanisms of the photo‐/electrocatalytic alkene difunctionalization reactions by selecting impressive synthetic examples, which are divided into four sections based on the final terminated step, including oxidative radical‐polar crossover coupling, reductive radical‐polar crossover coupling, radical‐radical coupling, and transition‐metal‐catalyzed coupling. [ABSTRACT FROM AUTHOR]

Pairing transition metals and heavier tetrylenes (Si, Ge, Sn, Pb) holds great potential for cooperative bond activation and catalysis. In this work, we investigate the reactivity of a low-coordinate Pt(0)/Ge(II) system that emerges from the reaction between the monoligated platinum(0) precursor [(PMe2ArDipp2)Pt(olefin)] with germylene dimer [ArDipp2GeCl]2 (where ArDipp2 = C6H3−2,6-(C6H3−2,6-iPr2)2). The resulting complex reveals ability for cooperative bond activation. Stoichiometric reactions with dihydrogen, water, methanol, ammonia and alkynes unveil the formation of Pt(II)-germyl compounds, characterized by distinct isomeric forms, whose flexibility derives from the particularly low-coordination. We explore its catalytic potential in the hydrodehalogenation of aliphatic, aromatic and main-group halides under dihydrogen atmosphere using both thermal and photochemical conditions, demonstrating promising conversions even for more challenging alkyl chlorides. Pairing transition metals and heavier tetrylenes holds potential for cooperative bond activation. Here, the authors investigate the reactivity of a low-coordinate Pt(0)/Ge(II) system that emerges from the reaction between a monoligated platinum(0) precursor with a germylene dimer and explore its application as a hydrodehalogenation catalyst. [ABSTRACT FROM AUTHOR]

The shape‐defined ZnFe2O4 spinel with cubic and octahedral morphology was hydrothermally synthesized, respectively, and used as catalyst precursor for Fischer–Tropsch synthesis (FTS). The structure of ZnFe2O4 spinel was changed to ZnO and Fe5C2 (Fe5C2/ZnO) after reduction and carbonization. Interestingly, ZnFe2O4 with cubic morphology exhibited much higher catalytic activity and selectivity toward low‐carbon olefins (C2–C4) than the octahedral one under identical conditions, and the latter tended to produce the saturated alkanes. The primary properties of ZnFe2O4 materials before and after reduction were systematically studied through a series of characteristic technologies to reveal the difference in catalytic performance between the two ZnFe2O4 spinels with different morphologies. [ABSTRACT FROM AUTHOR]

To alleviate CO2 emissions and reduce reliance on fossil fuels, a groundbreaking bifunctional catalyst system was introduced, which ingeniously merged CZZ with modified SAPO‐34 zeolite, to convert CO2 into light olefins. Different metals were impregnated into SAPO‐34 to form MeSAPO‐34 (Me = Zn, Zr, Mn) and the metal Zr content was altered. Furthermore, CZZ and MeSAPO‐34 was combined into CZZ/MeSAPO‐34 composite catalysts, which was used for CO2 hydrogenation. The MeSAPO‐34 and xZrSAPO‐34 catalysts were rigorously characterized by various techniques, revealing key physicochemical attributes. This innovative approach harnessed the synergistic effects between the metallic CZZ component and the modified zeolite to facilitate a series of reactions, effectively generating C2‐C4‐rich hydrocarbons. Benefiting from weak acid, higher oxygen vacancy concentration and interactions between components, the CZZ/ZrSAPO‐34 catalyst system has shown remarkable efficiency in enhancing the light olefin selectivity. The key aspects of this system are its ability to modulate surface acidity and oxygen vacancy concentration, thus creating favorable conditions for light olefin production via enhanced tandem reaction based on CO2 hydrogenation. This work enriches our insight into designing novel composite catalysts for promoting CO2 conversion and hence mitigating CO2 emissions. [ABSTRACT FROM AUTHOR]

Here, we report a strategy enabling triple switchable chemo‐, regio‐, and stereodivergence in newly developed palladium‐catalyzed cycloadditions of allenes. An asymmetric pseudo‐stereodivergent cycloaddition of allenes bearing a primary leaving group at the α‐position, where a dynamic kinetic asymmetric hydroalkoxylation of racemic unactivated allenes was the enantio‐determining step, is realized, providing four stereoisomers [(Z,R), (Z,S), (E,S), and (E,R)] containing a di‐substituted alkene scaffold and a stereogenic center. By tuning reaction conditions, a mechanistically distinctive cycloaddition is uncovered selectively with the same set of substrates. By switching the position of the leaving group of allenes, a cycloaddition involving an intermolecular O‐attack is disclosed. Diverse mechanisms of the cycloaddition reactions of allenes enable rapid access to structurally and stereochemically diverse 3,4‐dihydro‐2H‐1,4‐benzoxazines in high efficiency and selectivity. [ABSTRACT FROM AUTHOR]

Alkenes are fundamental functional groups which feature in various materials and bioactive molecules; however, efficient divergent strategies for their stereodefined synthesis are difficult. In this regard, numerous synthetic methodologies have been developed to construct carbon–carbon bonds with regio‐ and stereoselectivity, enabling the predictable and efficient synthesis of stereodefined alkenes. In fact, an appealing alternative approach for accessing challenging stereodefined alkene molecular frameworks could involve the sequential selective activation and cross‐coupling of strong bonds instead of conventional C−C bond formation. In this study, we introduce a series of programmed site‐ and stereoselective strategies that capitalizes on the versatile reactivity of readily accessible polymetalloid alkenes (i.e. polyborylated alkenes), through a tandem cross‐coupling reaction, which is catalyzed by an organometallic Rh‐complex to produce complex molecular scaffolds. By merging selective C−B and remote C−H bond functionalization, we achieve the in situ generation of polyfunctional C(sp2)‐nucleophilic intermediates. These species can be further modified by selective coupling reactions with various C‐based electrophiles, enabling the formation of C(sp2)−C(sp3) bond for the generation of even more complex molecular architectures using the readily available starting polyborylated‐alkenes. Mechanistic and computational studies provide insight into the origins of the stereoselectivities and C−H activation via a 1,4‐Rh migration process. [ABSTRACT FROM AUTHOR]

We report here a photoinduced iron-catalyzed fluoroalkylation-peroxidation of activated and/or unactivated alkenes with fluoroalkyl carboxylic acids and hydroperoxide. The ligand-to-iron charge transfer strategy effectively overcomes the high redox potential of the fluoroalkyl carboxylic acids, facilitating the difunctionalization reaction to occur smoothly under mild reaction conditions. The late-stage functionalization of drug and natural product derivatives was also demonstrated. [ABSTRACT FROM AUTHOR]

Chiral organofluorine compounds featuring a monofluoromethyl (CH2F)-substituted stereocenter are often encountered in a number of drugs and bioactive molecules. Consequently, the development of catalytic asymmetric methods for the enantioselective construction of CH2F-substituted stereocenters has made great progress over the past two decades, and a variety of enantioselective transformations have been accordingly established. According to the types of fluorinated reagents or substrates employed, these protocols can be divided into the following major categories: (i) enantioselective ring opening of epoxides or azetidinium salts by fluoride anions; (ii) asymmetric monofluoromethylation with 1-fluorobis(phenylsulfonyl)methane; (iii) asymmetric fluorocyclization of functionalized alkenes with Selectfluor; and (iv) asymmetric transformations involving α-CH2F ketones, α-CH2F alkenes, or other CH2F-containing substrates. This feature article aims to summarize these recent advances and discusses the possible reaction mechanisms, advantages and limitations of each protocol and their applications. Synthetic opportunities still open for further development are illustrated as well. This review article will be an inspiration for researchers engaged in asymmetric catalysis, organofluorine chemistry, and medicinal chemistry. [ABSTRACT FROM AUTHOR]

An expedient route to 2-aminodihydrothiophenes and their seleno analogues is reported. A three-component photoredox reaction between alkene, thio(seleno)cyanate, and bromomalonate is employed, generating a carbo-thio(seleno)cyanate intermediate that undergoes a domino of reactions mediated by alumina column chromatography, leading to valuable chalcogen pharmacophores. Mechanistic investigations using DFT and control experiments reveals an intramolecular H-bond responsible for driving the domino forward. [ABSTRACT FROM AUTHOR]

We report a new TADF-catalyzed aziridination of alkenes under visible light. In this protocol, a free triplet nitrene is in situ generated from the commercially available tosyl azide by energy transfer of the excited photocatalyst 4DPAIPN. Our finding enables the smooth installation of the strained aziridine ring into a remarkably wide scope of alkenes and pharmaceutical-derived olefins and natural products, as well as the synthesis of sitagliptin. This metal-free method provides a new opportunity for the late-stage modification of complex molecules or synthesis of nitrogen-containing pharmaceuticals. [ABSTRACT FROM AUTHOR]

We successfully synthesized trifluoromethylated β-ketosulfones via the reaction of vinyl triflates with alkenes employing aqueous sulfurous acid as an external source of SO2. The PhSSPh/photoinitiated reaction with vinyl triflates that contain electron-deficient groups or halogens did not show any base-related effects, whereas the radical reaction was impeded in the absence of a base in the case of vinyl triflates generated from phenylacetylenes. [ABSTRACT FROM AUTHOR]

Asymmetric de novo synthesis of benzocyclobutenes (BCBs) via catalytic intermolecular reaction is highly desired for efficient access to this important class of compounds, yet such a strategy remains unmet challenge. Here, we report a Pd/Pyrox‐catalyzed asymmetric [2+2] annulation between arylboronic acids and functionalized alkenes, providing an unprecedented efficient protocol to access various enantio‐enriched BCBs in a modular and versatile manner under mild conditions. A broad substrate scope with excellent enantioselectivity has been achieved under the current protocol. The isolation and characterization of the key chiral palladacycle intermediate, together with DFT calculations, provides strong evidence for the catalytic pathway including an enantiodetermining arylpalladation step. [ABSTRACT FROM AUTHOR]

Visible light‐mediated photocatalytic approach for the radical functionalization of alkenes bearing the fluorinated aryl sulfide fragment is described. The process occurs in the presence of organic photocatalyst using sulfinates as sources of radicals. The key step of the reaction is the intramolecular 1,4‐migration of the polyfluoroaryl group. In the reaction, three new bonds are formed (two C−C and one C−S bond). The decisive role of fluorine atoms in the reaction efficiency was confirmed by DFT calculations. [ABSTRACT FROM AUTHOR]

C-H activation is a powerful strategy for forming C-C bonds without the need for prefunctionalization. In this paper, we present a general, direct, and regioselective palladium-catalyzed functionalization of a phosphorus heterocycle, 2-phenyl-1H-isophosphinoline 2-oxide. The mild reaction conditions enabled the introduction of various functionalized alkenes. Moreover, the flame-retardant properties of selected products clearly highlighted the synergy between the phosphine oxide and another heteroatom-based group, even in the condensed phase. [ABSTRACT FROM AUTHOR]

We present an experimental and computational investigation into the rhodium-catalyzed ring-opening reactions of heterobicyclic alkenes with heteroarene nucleophiles. The reaction provides a facile route to trans-substituted dihydronaphthalen-1-ol and 1-amino-dihydronaphthalene products in up to a 95% yield as a single diastereomer. This reaction is 100% atom-economic and offers C–C bond formation without prior functionalization of the coupling partners. The mechanism and origins of selectivity were probed with density functional theory (DFT) at the MN15/Def2-TZVPP level of theory. The energetic barriers between iridium- and rhodium-catalyzed pathways were compared via DFT. Additionally, the reactivity and energetic barriers across diverse heterobicyclic alkenes and heteroarenes were calculated to unveil their relative reactivity. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed asymmetric [3+2] cycloaddition reaction of vinyl cyclopropane and electron-deficient dienes was realized. The cycloaddition reaction proceeded regioselectively on the distant C=C double bond of electron-deficient dienes, and was mainly controlled by the steric hindrance of the 5-substituent of electron-deficient dienes. Chiral multi-substituted cyclopentanes bearing three functional groups (monosubstituted alkene, conjugated ester, and cyano) and three continuous stereocenters were obtained in moderate to high yields, diastereoselectivities, and enantioselectivities. [ABSTRACT FROM AUTHOR]

The transition metal–catalyzed boronation reactions are considered as one of the most effective methods for the synthesis of alkylboranes in terms of functional group compatibility and reactivity. Herein, the mechanism of synergistic catalysis of alkene arylboration by [Cu]/[M] (M=Pd, Ni) bimetallic catalysts, as well as the regioselectivity and stereoselectivity of the reactions, has been investigated by using DFT calculations. The results show that four processes are involved in the whole reaction: [Cu]‐catalyzed borylcuprization of alkene, [Pd] or [Ni]‐catalyzed oxidative addition of halogenated aryl groups, transmetalation, and reductive elimination. [Cu]/[Ni] bimetallic catalysts show the same catalytic activity as [Cu]/[Pd] catalysts and are good economic alternatives for the alkene arylboration. The cleavage of B–B bond of B2Pin2 is the rate‐determining step. The regioselectivity of the title reaction is determined by the mode of the alkene insertion into the Cu–B bond. The attacking of C atom with the more electron‐rich character in alkyne makes for the formation of the main product. The small energy barrier difference between the rotation of the Cu‐C σ bond from the syn‐9 to the anti‐9 controls the stereoselectivity. Our findings provide a thorough explanation of the experimental results and shed light on the further development of the alkene functionalization. [ABSTRACT FROM AUTHOR]

The volatile components of Stropharia rugosoannulata and Tricholoma lobayense were analyzed by mass spectrometry, and the relative contents of each component were determined by the internal standard method. In Stropharia rugosoannulata, 58 volatile components were identified, including 10 alcohols, 14 esters, 9 aldehydes, 5 ketones, 1 phenol, 3 alkanes, 4 amines, 5 acids, 1 furan, 1 pyrazine, 1 olefin, 1 oxime, 1 pyrazole, and 2 other components. Among them, the most abundant volatile component was hexanal (1655.40 ng/g), followed by pentanoic acid (1503.10 ng/g) and phenylethyl alcohol (1215.94 ng/g). In Tricholoma lobayense, 68 volatile components were identified, including 17 aldehydes, 11 ketones, 8 acids, 10 esters, 5 alcohols, 1 phenol, 2 furans, 4 alkanes, 1 alkene, 1 oxime, 1 pyrazole, 1 amine, and 6 other components. Among them, the most abundant volatile component was benzaldehyde (2190.67 ng/g), followed by hexanal (1708.81 ng/g) and furan, 2-pentyl- (838.45 ng/g). There were 21 common volatile components between the two different edible fungi, including 7 aldehydes, 5 esters, 3 ketones, 2 alcohols, 2 acids, 1 oxime, and 1 furan. [ABSTRACT FROM AUTHOR]

The use of EtOH as hydrogen donor is remarkably under explored in transfer hydrogenation reactions, even though EtOH represents an appealing hydrogen source. With the cationic ruthenium complex [Ru(PYA)(cymene)]+, 1, containing a N,N‐bidentate amino‐functionalized pyridinium amidate (PYA) ligand as catalyst precursor, we here demonstrate the first example of chemoselective room temperature transfer hydrogenation of the C═C bond in α,β‐unsaturated ketones using EtOH as benign hydrogen source to yield a variety of functionalized ketones. The reaction proceeds under mild conditions with K2CO3 as base and conventiently at room temperature. A broad substrate scope, including various functionalized α,β‐unsaturated carbonyl groups, demonstrates the general applicability of this method. Preliminary mechanistic studies suggest the formation of an alkoxide complex [1]–OEt as an initially formed species, and the requirement for EtOH to induce hydride transfer, suggesting a protic activation of the catalyst. [ABSTRACT FROM AUTHOR]

The one‐carbon degradation  of aliphatic carboxylic acids has been studied using a H2IrCl6‐Ru(CO)4I2 bimetallic catalyst. Alkanes, RH, have been obtained from the corresponding RCOOH in good to near quantitative yields via a process that is thought to involve (i) a decarbonylation process that involves the formation of alkenes along with CO and H2O, (ii) a water–gas shift (WGS) reaction to give H2 and CO2, and (iii) the hydrogenation of the resulting alkenes. [ABSTRACT FROM AUTHOR]

Hydrogen atom transfer (HAT) from a metal-hydride is a reliable and powerful method for functionalizing unsaturated C–C bonds in organic synthesis. Cobalt hydrides (Co–H) have garnered significant attention in this field, where the weak Co–H bonds are most commonly generated in a catalytic fashion through a mixture of stoichiometric amounts of peroxide oxidant and silane reductant. Here we show that the reverse process of HAT to an alkene, i.e. hydrogen atom abstraction of a C–H adjacent to a radical, can be leveraged to generate catalytically active Co–H species in an application of shuttle catalysis coined shuttle HAT. This method obviates the need for stoichiometric reductant/oxidant mixtures thereby greatly simplifying the generation of Co–H. To demonstrate the generality of this shuttle HAT platform, five different reaction manifolds are shown, and the reaction can easily be scaled up to 100 mmol. Hydrogen atom transfer (HAT) from a metal-hydride is a reliable and powerful method for functionalizing unsaturated C–C bonds in organic synthesis. Herein, the authors show that reverse process of HAT to an alkene can be leveraged to generate catalytically active Co–H species in an application of shuttle catalysis coined shuttle HAT. [ABSTRACT FROM AUTHOR]

The cleavage of double bonds in alkenes constitutes an integral process in converting feedstock materials into high-value synthetic intermediates. Well-known examples such as the oxidative cleavage of olefins and olefin metathesis only facilitate the synthesis of oxygen-containing compounds and the recombination of olefins. Therefore, it is appealing to extend C=C double bond cleavage to yield more abundant transformations. Herein, we report a novel photocatalytic approach for the deconstructive carboxylation of alkenes with CO2 for the synthesis of carboxylic acids in the absence of transition metals. Compared with reported carboxylations with CO2 during which carbon numbers are typically increased, we achieve the exchange of carbon dioxide with one of the carbons of the alkene double bond, thus providing carboxylic acids with unchanged carbon numbers when terminal alkenes are used. [ABSTRACT FROM AUTHOR]

The electrophilic thiolation of alkenes initiated by DMTSM and the addition of CF3 SO2 Na in one pot has been developed. This reaction also can be extended to ArSO2 Na. This protocol features a good substrate scope, simple procedures, and mild reaction conditions and affords the desired products in moderate yields without metal catalysts. [ABSTRACT FROM AUTHOR]

We studied the influence of the distance of olefin metathesis catalysts from the inner surface of a mesoporous support on macrocyclization and Z‐selectivity under confinement. For these purposes, the cationic molybdenum imido alkylidene N‐heterocyclic carbene (NHC) catalysts [Mo(N‐(2‐tBu‐C6H4)(1‐mesityl‐3‐(3‐trimethoxysilylprop‐1‐yl)‐imidazol‐2‐ylidene)(CHCMe2Ph)(MeCN)Br+ B(ArF)4−] Mo2, [Mo(N‐(2‐tBu‐C6H4)(1‐mesityl‐3‐(3‐trimethoxysilylprop‐1‐yl)‐imidazol‐2‐ylidene)(CHCMe2Ph)(MeCN)OTf+ B(ArF)4−] Mo3, [Mo(N‐(2,6‐Me2‐C6H3)(1‐mesityl‐3‐(3‐trimethoxysilylprop‐1‐yl)‐imidazol‐2‐ylidene)(CHCMe2Ph)(MeCN)Br+ B(ArF)4−] Mo5, and [Mo(N‐(2,6‐iPr2‐C6H3)(1‐mesityl‐3‐(3‐trimethoxysilylprop‐1‐yl)‐imidazol‐2‐ylidene)(CHCMe2Ph)(MeCN)+Br B(ArF)4−] Mo7 (B(ArF)4 = tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate), all containing a trimethoxysilylpropyl tether, were selectively immobilized inside the mesopores of SBA‐15. Under confinement, both macro(mono)cyclization (MMC) and Z‐selectivity were higher than in solution but lower than with catalysts directly bound to the surface of the mesoporous supports. These findings are in agreement with existing theoretical models on substrate and product distribution in mesopores, which suggest that the highest substrate concentration is found at the pore wall and that it increases with decreasing pore diameter. [ABSTRACT FROM AUTHOR]

In this work, we described a general monometallic cobalt heterogeneous catalyst for the hydroformylation of olefins, achieving good yields and recyclability up to five times with no loss in catalytic activity. These catalysts were prepared through the pyrolysis of the well‐defined metal–organic framework ZIF‐67. The addition of steam during the pyrolysis did not affect the final phase composition of the cobalt particles; nonetheless, it resulted in an increase of the cobalt particle size and the partial removal of the carbonaceous matrix. The materials were extensively characterized by several techniques, and it was observed that the N‐doped carbon matrix played a crucial role in terms of activity and stability. Different liquid olefins, including internal, terminal, and cyclic were successfully tested in our hydroformylation protocol. Aldehydes yields of 48%–77% for different liquid olefins were achieved with the optimal catalyst. No leaching of the active sites was observed over five catalytic cycles. The high stability of the catalyst is attributed to the presence of stabilizing nitrogen atoms bearing the cobalt sites. [ABSTRACT FROM AUTHOR]

Persistent challenges in hydroformylation of olefins include controlling regioselectivity, particularly for short aliphatic olefins and conducting reactions under ambient conditions. We report here the synthesis of monophosphine–Rh complexes on a typical chelated diphosphine ligand mediated by a Zr‐MOF through isolating a pair of phosphorus atoms. We demonstrate that single‐crystal X‐ray diffraction can elucidate the structural transformation of the Rh catalyst during olefin hydroformylation, providing valuable information on active site reconstruction during catalysis. The Rh‐MOF catalyst demonstrates excellent catalytic and recyclable performance in the hydroformylation of short aliphatic olefins with linear to branched ratios of up to 99 : 1. Due to the framework's capacity to adsorb and concentrate gases, the catalytic reactions occur under room temperature and pressure, eliminating the need for the high temperature and pressures typically required in homogeneous systems. This study show that Zr–MOF can be a unique platform for synthesizing unusual catalytic species that cannot exist in solutions for meaningful chemical transformations and elucidate valuable structural information pertaining to metal‐based catalysis. [ABSTRACT FROM AUTHOR]

Catalytic removal of alkynes is essential in industry for producing polymer‐grade alkenes from steam cracking processes. Non‐noble Ni‐based catalysts hold promise as effective alternatives to industrial Pd‐based catalysts but suffer from low activity. Here we report embedding of single‐atom Pd onto the NiGa intermetallic surface with replacing Ga atoms via a well‐defined synthesis strategy to design Pd1−NiGa catalyst for alkyne semi‐hydrogenation. The fabricated Pd1Ni2Ga1 ensemble sites deliver remarkably higher specific mass activity under superb alkene selectivity of >96 % than the state‐of‐the‐art catalysts under industry‐relevant conditions. Integrated experimental and computational studies reveal that the single‐atom Pd synergizes with the neighbouring Ni sites to facilitate the σ‐adsorption of alkyne and dissociation of hydrogen while suppress the alkene adsorption. Such synergistic effects confer the single‐atom Pd on the NiGa intermetallic with a Midas touch for alkyne semi‐hydrogenation, providing an effective strategy for stimulating low active Ni‐based catalysts for other selective hydrogenations in industry. [ABSTRACT FROM AUTHOR]

A Pd‐catalyzed asymmetric isomerization‐hydroamidocarbonylation of amide‐containing alkenes was developed, affording a variety of chiral α‐alkyl succinimides in moderate to good yields with high enantioselectivities. The key to success was introducing bulky 1‐adamentyl P‐substitution and 2,3,5,6‐tetramethoxyphenyl group into the rigid P‐chirogenic bisphosphine ligand to create stronger steric hinderance and deeper catalytic pocket. By this approach, regio‐ or stereo‐convergent synthesis of enantiomeric succinimides from the mixture of olefin isomers was achieved. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed highly C−S‐selective Stille cross‐coupling between aryl thianthrenium salts and tri‐ or tetrasubstituted alkenyl stannanes is described. Herein, critical challenges including site‐ and chemoselectivity control are well addressed through C−H thianthrenation and C−S alkenylation, thereby providing an expedient access to stereodefined tri‐ and tetrasubstituted alkenes in a stereoretentive fashion. Indeed, the palladium‐catalyzed Stille‐alkenylation of poly(pseudo)halogenated arenes displays privileged capability to differentiate C−S over C−I, C−Br, C−Cl bonds, as well as oxygen‐based triflates (C−OTf), tosylates (C−OTs), carbamates and sulfamates under mild reaction conditions. Sequential and multiple cross‐couplings via selective C−X functionalization should be widely applicable for increasing functional molecular complexity. Modular installation of stereospecific alkene motifs into pharmaceuticals illustrated the synthetic application of the present protocol in drug discovery. [ABSTRACT FROM AUTHOR]