Nickel Chain-Walking Catalysis: A Journey to Migratory Carboboration of Alkenes

Approach Toward Stereoselective α-Arylation by Pd/Cu-Catalyzed Arylboration of Electron Deficient Alkenes

Palladium-catalyzed cross coupling of enolates-α-arylation-is an established method for chemical synthesis. A major challenge in the field is control of stereochemistry for the α-carbon. This is typically due to facile epimerization under the basic reaction conditions for α-arylation. In this study, an alternative approach is presented that involves the Pd/Cu-catalyzed arylboration of electron deficient alkenes. The products are generated with high levels of diastereoselectivity for a broad range of substitution patterns. Enantioselective variants are also presented in addition to product derivatizations.

Iron-Catalyzed Tunable Alkene Migratory Silylation and Transposition

The example of iron-catalyzed alkenes migratory silylation and transposition has been demonstrated, affording a tunable approach to synthesize thermodynamically stable allylsilanes and internal alkenes with high efficiency and regioselectivity. These reactions showcase several advantageous features, including good functional group tolerance, excellent regioselectivity, a broad substrate scope, scalability to gram-scale synthesis, and late-stage functionalization of bio-relevant molecules. Furthermore, the relay catalytic mechanism of the migratory silylation, involving both iron-silyl and iron-hydride intermediates, provides valuable insights into iron-catalyzed coupling reactions, opening new avenues for the development of novel transformations under iron catalysis.

Nickel-Catalyzed Adaptive Migration-Enabled Asymmetric Cross-Hydrocarbonylation of Unactivated Alkenes

Transition-metal-catalyzed regio- and enantioselective cross-coupling of alkyl metallic species has emerged as a cornerstone in modern organic synthesis, which enables the construction of carbon-carbon and carbon-heteroatom bonds with high precision to facilitate rapid access to important organic targets with molecular complexity. However, the selective formation and utilization of different alkyl metallic intermediates from one precursor under identical conditions remain unknown and challenging. Herein, a Ni-catalyzed adaptive migratory asymmetric cross-hydroacylation of unactivated alkenes for the synthesis of enantioenriched α-arylated ketones has been developed. One alkene serves as a precursor for two different alkyl metallic intermediates by adaptive migration, providing one of the most straightforward pathways to access enantioenriched α-arylated ketones.

Nickel/Photoredox Dual-Catalyzed, Regioselective 1,2-Carboacylation of Alkenes via Synergistic Alkyl and Benzoyl Radical Coupling

A regioselective 1,2-carboacylation protocol of alkenes via nickel/photoredox dual catalysis has been successfully developed under mild conditions. A wide range of alkyl bromides, α-oxocarboxylic acids, and styrenes proved to be compatible under the optimized conditions, affording the corresponding 1,2-carboacylation products in up to 91% yields. Mechanistically, the key to the success of this approach is the temporal orchestration of radical generation: nickel-catalyzed halogen atom transfer (XAT) for alkyl bromides and photoredox-driven decarboxylation for α-oxocarboxylic acids.

Harnessing the β-boron effect for regioselective Ru-catalyzed hydrosilylation of internal alkynes

Metal-catalyzed hydrosilylation of alkynes is recognized as a straightforward and atom economic method for synthesizing alkenylsilanes. While substantial advancements have been made with terminal alkynes, achieving precise regio- and stereocontrol with unsymmetrical internal alkynes remains a significant challenge. In this study, we report the utilization of an intriguing β-boron effect in metal catalysis, enabling an exclusively regioselective Ru-catalyzed hydrosilylation of propargylic N-methyliminodiacetic acid boronates (B(MIDA)) to synthesize alkenylsilanes. Variations in the Ru catalyst can lead to stereo-divergency without compromising regioselectivity. Density functional theory (DFT) calculations indicate that the hyperconjugative effect of the σ(C-B) bond, which stabilizes the electrophilic metallacyclopropene intermediate with Fischer carbene character, is crucial for achieving high regioselectivity. The observed switch in stereoselectivity is attributed to the different steric effects of 1,2,3,4,5-pentamethylcyclopenta-1,3-diene (Cp*) and cyclopenta-1,3-diene (Cp) ligands in the catalyst. This method produces a diverse array of regio- and stereodefined products incorporating boryl, silyl, and alkene functionalities, each of which serves as a valuable handle for further functionalization.

Modular Access to Arylethylamines Enabled by Ni-Catalyzed Markovnikov-Selective Hydroarylation of Allylic Amines

Arylethylamines are prevalent structural skeletons in bioactive molecules and have significant interest within the organic chemistry community. We report here a modular and efficient nickel-catalyzed Markovnikov-selective hydroarylation of readily available allylic amines, delivering a wide variety of valuable arylethylamines with complete regiocontrol under mild conditions. Key to the success of this protocol is the employment of bulky N-heterocyclic carbenes (NHCs) as ligands. Furthermore, the use of chiral NHC ligands enables straightforward access to enantioenriched arylethylamines with excellent regio- and enantioselectivities.

Nickel-Catalyzed 1,1-Carboboration of Polysubstituted Internal Alkenes

Herein, we report a nickel-catalyzed 1,1-carboboration of di- and trisubstituted alkenyl boronates through a chain-walking strategy. This reaction effectively addresses the polarity-mismatch problem via ligand control, enabling the coupling of various carbon-based electrophiles while accommodating a broad range of functional groups. The approach yields diverse tetrasubstituted carbon gem-diboronate derivatives with exceptional regioselectivity. The synthetic utility of this method is further demonstrated through the concise synthesis of high-value bioactive molecules.

Through-Space 1,4-Ni/H Shift: Unlocking Migration along Coupling Partners in Olefin Borylcarbofunctionalization

Olefin migratory functionalization is a well-established strategy for the selective installation of functional groups at remote C(sp3)-H positions along an alkyl chain. However, prior research has predominantly focused on migration along the alkene component. Herein, we describe a conceptually new migratory coupling strategy for the difunctionalization of alkenes, where migration selectively occurs along the C(sp2) coupling partner rather than the alkene component, facilitated by a through-space 1,4-Ni/H shift. This approach offers a modular three-component strategy for the selective and efficient construction of densely functionalized alkyl boronates from readily accessible chemicals. Moreover, by integrating the 1,2-Ni/H shift with the 1,4-Ni/H shift, this platform has been expanded to achieve a two-fold migration along both the alkene components and the coupling partners, facilitating selective borylative remote C(sp3)─H/C(sp2)─H cross-coupling.

MeOH-Triggered Halogen-Atom Transfer of Unactivated Alkyl Bromides Enabling the Photoredox Giese Addition

Herein, a nickel-catalyzed, photoredox Giese addition reaction with readily accessible alkyl bromides, driven by readily available feedstock MeOH as the halogen-atom transfer (XAT) reagent, was successfully achieved under mild conditions. The versatility of this protocol was demonstrated through a range of structurally varied alkyl bromides and Giese-type acceptors with moderate to good yields. Mechanistic investigation highlights that the formation of alkyl radicals through the XAT of alkyl bromides was tentatively prompted by •CH2OH, which was derived from the sequential photo-oxidation/1,2-hydrogen-atom transfer of MeOH.

Cobalt-Catalyzed Remote Site-Selective Hydroboration of Unactivated Alkenes via Chain-Walking Strategy

An expedient synthesis of α-aminoboronic acid derivatives via cobalt-catalyzed remote site-selective hydroboration of unactivated alkenes is described herein. The strategy is characterized by its simplicity, site-selectivity, and wide substrate scope, as both terminal and internal alkenes could undergo the reaction smoothly, affording the corresponding products in good yields. According to the mechanism, Co-H is generated from Co(acac)2 in the presence of HBpin, which starts the chain-walking strategy via a series of alkene insertion and β-H elimination process.

Remote Migratory Reductive Arylation of Unactivated Alkenes Enabled by Electrochemical Nickel Catalysis

Transition metal-catalyzed cross-coupling reaction between organometallic reagents and electrophiles is a potent method for constructing C(sp2)-C(sp3) bonds. Given the characters of organometallic reagents, cross-reductive coupling is emerging as an alternative strategy. The resurgence of electrochemistry offers an ideal method for electrochemical reductive of cross-coupling electrophiles. Inspired by the mechanism of electrochemical metal hydride, our study proposed that Ni-H electrochemically catalyze the hydroarylation coupling of unactivated alkenes with aryl halides. 1,1-Diarylalkanes can be produced effectively. This method have advantages including mild conditions, excellent regioselectivity, and satisfactory yields.

Palladium-catalyzed enantioselective β-hydride elimination for the construction of remote stereocenters

The β-H elimination is a crucial elementary step in transition-metal catalysis, but controlling the stereochemistry of this process has been underdeveloped. The limited works reported so far have only focused on creating axial chirality in allenes, and no report has been able to build central chirality using asymmetric β-H elimination. In this study, we report a Trost ligand-enabled enantioselective desymmetric β-H elimination reaction from π-allyl-Pd. This transformation provides rapid access to cyclohexenes bearing a C4-remoted stereocenter, and total synthesis of (-)-oleuropeic acid and (-)-7-hydroxyterpineol is demonstrated. Computational studies have shown that the β-H elimination is the rate-determining step, and the non-covalent interactions between the amide moiety of the Trost ligand and the benzene and cyclohexane moieties of the substrate play a key role in stereocontrol during the β-H elimination.

Enantioselective Cobalt-Catalyzed Remote Hydroboration of Alkenylboronates

Heteroatomic groups in alkenes typically direct thermodynamically favored chain walking of C═C bonds toward themselves, thereby facilitating C-H bond functionalization near the heteroatoms. We present herein an efficient cobalt-catalyzed contra-thermodynamic remote hydroboration of alkenylboronates with pinacolborane to synthesize chiral 1,n-diboronates. This protocol features a broad substrate scope, high functional group tolerance, and excellent enantioselectivity. Mechanistic studies indicate the involvement of a chain-walking process. Gram-scale reactions and various product derivatizations further highlight its practicality.

Ni-catalysed acceptorless dehydrogenative aromatisation of cyclohexanones enabled by concerted catalysis specific to supported nanoparticles

The dehydrogenative aromatisation of cyclohexanone derivatives has had a transformative influence on the synthesis of aromatic compounds because functional groups can be easily introduced at desired positions via classic organic reactions without being limited by ortho-, meta- or para-orientations. However, research is still limited on acceptorless dehydrogenative aromatisation, especially with regard to nonprecious-metal catalysts. Ni is a promising candidate catalyst as a congener of Pd, but thermally Ni-catalysed dehydrogenative aromatisation has not been reported even in an oxidative manner because of the difficulty of β-hydride elimination and the fast re-insertion of Ni-H species. Here, we report a CeO2-supported Ni(0) nanoparticle catalyst for acceptorless dehydrogenative aromatisation of cyclohexanone derivatives. This catalyst is widely applicable to various compounds such as cyclohexanols, cyclohexylamines, N-heterocycles, enamines and β-heteroatom-substituted ketones. Through various experiments, we demonstrate that the present reaction was achieved by the concerted catalysis utilizing metal ensembles unique to supported metal nanoparticle catalysts.

Enantioselective Copper-Catalyzed Three-Component Cascade Boronation-Dearomatization Reaction: Synthesis of Chiral Boron-Containing 1,4-Dihydropyridines

A three-component cascade boronation-dearomatization reaction of alkenes, a diboron compound, and a pyridinium salt is diclosed, affording chiral boron-containing 1,4-dihyropyridines in high yields (≤98%) and diastereoselectivity (≤10:1 dr), along with excellent enantioselectivity (typically >99% ee). The catalytic system performs efficiently at low catalyst loadings (1 mol %) and was tested with >50 examples, including some biologically active molecules.

Ni-catalyzed regioselective and site-divergent reductive arylalkylations of allylic amines

Catalytic methods by switching the least parameters for regioselective and site-divergent transformations to construct different architectures from identical and readily available starting materials are among the most ideal catalytic protocols. However, the associated challenge to precisely control both regioselectivity and site diversity renders this strategy appealing yet challenging. Herein, Ni-catalyzed cross-electrophile regioselective and site-divergent 1,2- and 1,3-arylalkylations of N-acyl allylic amines have been developed. This Ni-catalyzed reductive three-component protocol enables 1,2-arylalkylation and 1,3-arylalkylation of allylic amines with aryl halides and alkyl halides with excellent chemo-, regio- and site-selectivity, representing the first example of controlled migratory difunctionalization of alkenes under reductive conditions. A wide range of terminal and internal unactivated allylic amines, aryl halides and alkyl precursors were tolerated, providing straightforward and efficient access to diverse C(sp3)-rich branched aliphatic amines from identical starting materials.

Visible-Light Induced and Iron Peroxo-Promoted Radical Difunctionalization of Alkene for the Synthesis of β-Ketosulfone and α-Chloroketone

In this work, a switchable synthesis of β-ketosulfone and α-chloroketone through a radical difunctionalization of alkenes is reported. The transformation works well under iron peroxo species/photoredox dual catalysis and an open-flask atmosphere, and the reaction is highlighted with good yields and a broad reaction scope. Mechanism studies show that the reaction is initiated by a formal [4 + 2] cyclization of the sulfonyl radical in a regioselective manner.

Borenium-Catalyzed "Boron Walking" for Remote Site-Selective Hydroboration

Remote functionalization through progressive olefin isomerization enables site-selective modification at a distal position, diversifying the synthetic approaches. However, the developed protocols have long relied on transition metal catalysis. Transition metal catalysts are deemed irreplaceable, albeit facing challenges in metal residue and catalyst poisoning. In this work, we present a pioneering approach that employs a borenium ion as a catalyst for site-selective, remote borylation, eliminating the need for metal catalysts. As the reaction progresses, borylation isomers at different positions emerge, gradually and ultimately converging into the predominant α-borylation product. This process is akin to a "walking" of a boron moiety along a carbon skeleton toward an aryl terminus. Detailed mechanistic studies and DFT calculations substantiate the borenium-catalyzed, stepwise migration via a reversible B-H insertion/elimination sequence. This remote borylation exhibits good functional group compatibility, complementing those methods reliant on transition metals. Furthermore, this metal-free protocol permits the convenient synthesis of silyl-remote-boryl compounds, demonstrating an opposite regioselectivity to that observed in transition-metal-catalyzed tandem silylation-borylation reactions. This discovery therefore contributes to site-selective, remote difunctionalization via sequential C-B and C-Si derivatizations, exemplified by the synthesis of amino-remote-alcohol bioactive molecules.

Nickel-Catalyzed Three-Component 1,1-Difunctionalization of Unactivated Alkenes with Quinoxaline/Naphthoquinone and Arylboronic Acids via Organometallic-Radical Relay

A nickel-catalyzed intermolecular three-component 1,1-difunctionalization of unactivated alkenes with quinoxaline/naphthoquinone and arylboronic acids via organometallic-radical relay is developed. This efficient protocol provides a new method to access a variety of arylalkanes in moderate to good yields with a broad substrate scope and excellent functional group tolerance. The mechanistic studies provide insights into the mechanism and origin of chemo- and regioselectivity as well as confirm the generation of functionalized benzylic radicals.

Reversible C-CN Bond Cleavage by a Formal Dinickel(I) Hydride Cation

An N-heterocyclic carbene (NHC) ligand supports a stable [Ni2H]+ core, formally dinickel(I). This diamagnetic cation complex features a bent hydride bridge and a Ni···Ni distance, 2.9926(5) Å, larger than two covalent radii. The cation displays weakly protic character, undergoing deprotonation by strong base to form the corresponding (NHC)nickel(0) dimer. Its reaction with aliphatic nitriles results in C-CN bond cleavage. The organic products of this reaction suggest that this bond-breaking step involves reactive nickel alkyl intermediates and occurs reversibly.

Creating glycoside diversity through stereoselective carboboration of glycals

Site-specific modification of glycosides to enhance or alter the physiological properties of the parent molecule has become a highly attractive strategy in drug development. However, creating glycoside building blocks with multiple diversifiable positions from readily available sugar precursors remains a challenging task. Herein, we present a highly regio- and stereoselective nickel-catalyzed carboboration of glycals, which offers a platform for generating glycoside diversity with diverse C1 and C2 modification potential. Specially, the integration of a readily modifiable boronate group at the C2 position markedly amplifies the versatility of this approach, furnishing a universal method for swiftly generating diverse rare sugars with C2-site modifications through expedited downstream transformations. This method demonstrates a broad substrate scope and tolerates various functional groups and complex natural or drug molecular architectures. Moreover, we illustrate the synthetic potential of this method through the synthesis of a diverse array of analogs of both natural products and pharmaceuticals.

Multifunctionalization of Alkenyl Alcohols via a Sequential Relay Process

Aryl-substituted aliphatic amines are widely recognized as immensely valuable molecules. Consequently, the development of practical strategies for the construction of these molecules becomes increasingly urgent and critical. Here, we have successfully achieved multifunctionalization reactions of alkenyl alcohols in a sequential relay process, which enables transformation patterns of arylamination, deuterated arylamination, and methylenated arylamination to the easy access of multifarious arylalkylamines. Notably, a novel functionalization mode for carbonyl groups has been developed to facilitate the processes of deuterium incorporation and methylene introduction, thereby providing new means for the diverse transformations of carbonyl groups. This methodology displays a wide tolerance toward functional groups, while also exhibiting good applicability across various skeletal structures of alkenols and amines.

Ni-catalysed remote C(sp3)-H functionalization using chain-walking strategies

The dynamic translocation of a metal catalyst along an alkyl side chain - often coined as 'chain-walking' - has opened new retrosynthetic possibilities that enable functionalization at unactivated C(sp3)-H sites. The use of nickel complexes in chain-walking strategies has recently gained considerable momentum owing to their versatility for forging sp3 architectures and their redox promiscuity that facilitates both one-electron or two-electron reaction manifolds. This Review discusses the relevance and impact that these processes might have in synthetic endeavours, including mechanistic considerations when appropriate. Particular emphasis is given to the latest discoveries that leverage the potential of Ni-catalysed chain-walking scenarios for tackling transformations that would otherwise be difficult to accomplish, including the merger of chain-walking with other new approaches such as photoredox catalysis or electrochemical activation.

Regiodivergent Radical-Relay Alkene Dicarbofunctionalization

Herein, we report a regiodivergent 1,n-dicarbofunctionalization of unactivated olefins enabled by a Ni-catalyzed radical relay that forges both C(sp3)-C(sp3) and C(sp2)-C(sp3) linkages, even at long-range. Initial studies support an intertwined scenario resulting from the merger of an atom-transfer radical addition (ATRA) and a chain-walking event, with site-selectivity being dictated by a judicious choice of the ligand backbone.

Nickel-Catalyzed Stereoconvergent C(sp2)-F Alkenylation of Monofluoroalkenes

The stereoconvergent synthesis of a single stereoisomer from E/Z-olefin mixtures remains one of the foremost challenges in organic synthesis. Herein, we describe a nickel-catalyzed stereoconvergent cross-coupling between E- and Z-mixed monofluoroalkenes and alkenyl electrophiles, which allows the construction of C(sp2)-C(sp2) bonds. This defluorinative transformation offers facile access to various 1,3-dienes with E-selectivity and good functional group tolerance. Preliminary mechanistic studies indicate that the reaction most likely proceeds through a migratory insertion/β-F elimination/isomerization process.

Stereoselective Construction of Multifunctional C-Glycosides Enabled by Nickel-Catalyzed Tandem Borylation/Glycosylation

Stereochemically pure saccharides have indispensable roles in fields ranging from medicinal chemistry to materials science and organic synthesis. However, the development of a simple, stereoselective, and efficient glycosylation protocol to access α- and β-C-glycosides (particularly 2-deoxy entities) remains a persistent challenge. Existing studies have primarily focused on C1 modification of carbohydrates and transformation of glycosyl radical precursors. Here, we innovate by harnessing the in situ generated glycosyl-Ni species to achieve one-pot borylation and glycosylation in a cascade manner, which is enabled by an earth-abundant nickel-catalyzed carboboration of readily accessible glycals without any ligand. This work reveals the potential for the development of a modular and multifunctional glycosylation platform to facilitate the simultaneous introduction of C-C and C-B bonds at the stereogenic center of saccharides, a largely unexploited research area. Preliminary experimental and computational studies indicate that the endocyclic O and the C3 group play important roles in stereoseclectively forging glycosidic bonds. As a result, a diverse range of C-R (R = alkyl, aryl, and alkenyl) and 2-deoxygenated glycosides bearing modifiable boron groups could be rapidly made with excellent stereocontrol and exhibit remarkable functional group tolerance. The synthetic potential is underscored in the late-stage glycosylation of natural products and commercial drugs as well as the facile preparation of various rare sugars, bioactive conjugates, and key intermediates to prorocentin, phomonol, and aspergillide A.

Photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated olefins with aryl bromides

Transition-metal-catalyzed hydroarylation of unactivated alkenes via metal hydride hydrogen atom transfer (MHAT) is an attractive approach for the construction of C(sp2)-C(sp3) bonds. However, this kind of reaction focuses mainly on using reductive hydrosilane as a hydrogen donor. Here, a novel photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated alkenes with aryl bromides using protons as a hydrogen source has been developed. This reaction represents the first example of photoinduced MHAT via a reductive route intercepting an organometallic coreactant. The key to this transformation was that the CoIII-H species was generated from the protonation of the CoI intermediate, and the formed CoIII-C(sp3) intermediate interacted with the organometallic coreactant rather than reacting with nucleophiles, a method which has been well developed in photoinduced Co-catalyzed MHAT reactions. This reaction is characterized by its high catalytic efficiency, construction of quaternary carbons, simple reaction conditions and expansion of the reactive mode of Co-catalyzed MHAT reactions via a reductive route. Moreover, this catalytic system could also be applied to complex substrates derived from glycosides.

Bis(pinacolato)diboron-Enabled Ni-Catalyzed Reductive Arylation/Vinylation of Alkyl Electrophiles

Herein, the use of economically and environmentally friendly bis(pinacolato)diboron (B2Pin2) is described as a non-metallic reductant in mediating Ni-catalyzed C(sp3)-C(sp2) reductive cross-coupling of alkyl electrophiles with aryl/vinyl halides. This method exhibits excellent suitability for heteroaryl halides and alkyl halides/Katritzky salts. The present study is compatible with an in situ halogenation of alcohol method, allowing for selective mono-functionalization of diols and bio-relevant alcohols (e.g., carbohydrates). The use of B2Pin2 shows potential for easy scalability without introducing additional metal impurities into the products. It is observed for the first time in the realm of cross-electrophile coupling chemistry that B2Pin2 can sever as a reductant to reduce NiII to Ni0. This mechanistic insight may inspire the development of new reductive bond-forming methodologies that can otherwise be difficult to achieve with a metal reductant.

Diverse Synthesis of C-Glycosides by Stereoselective Ni-Catalyzed Carboboration of Glycals

C-Glycosides are important structures that are common to natural products and pharmaceutical agents. Established methods for their synthesis involve the reaction of an activated anomeric carbon. In this study, we report a conceptually new approach that involves the stereoselective Ni-catalyzed carboboration of glycals. In these reactions, not only is a C-C bond formed at the anomeric carbon, but a synthetically useful C-B bond is also installed. Upon C-B oxidation, differentially protected C-glycosides to be formed. In addition, stereospecific manipulation of the C-B bond leads to diverse C-glycosides. Finally, we report the application of this method in the synthesis of established C-glycosides, such as C-glycosyl amino acids, as well as a strategy to make all possible diastereomers at C1 and C2.

Catalytic Regio- and Enantioselective Remote Hydrocarboxylation of Unactivated Alkenes with CO2

The catalytic regio- and enantioselective hydrocarboxylation of alkenes with carbon dioxide is a straightforward strategy to construct enantioenriched α-chiral carboxylic acids but remains a big challenge. Herein we report the first example of catalytic highly enantio- and site-selective remote hydrocarboxylation of a wide range of readily available unactivated alkenes with abundant and renewable CO2 under mild conditions enabled by the SaBOX/Ni catalyst. The key to this success is utilizing the chiral SaBOX ligand, which combines with nickel to simultaneously control both chain-walking and the enantioselectivity of carboxylation. This process directly furnishes a range of different alkyl-chain-substituted or benzo-fused α-chiral carboxylic acids bearing various functional groups in high yields and regio- and enantioselectivities. Furthermore, the synthetic utility of this methodology was demonstrated by the concise synthesis of the antiplatelet aggregation drug (R)-indobufen from commercial starting materials.

Enantioselective Synthesis of β-Aminoboronic Acids via Borylalkylation of Enamides

Aminoboronic acids represent a class of significant compounds that have attracted significant attention in the fields of drug discovery and organic synthesis. Despite notable progress in their synthesis, the efficient construction of chiral β-aminoboronic acids with alkyl side chains remains a challenging endeavor. Here, we introduce an unprecedented nickel-catalyzed asymmetric borylalkylation of enamides, employing a simple chiral diamine ligand, readily available B2pin2, and alkyl halides as coupling partners. This reaction serves as an efficient platform for assembling a diverse range of β-aminoboronic acid derivatives with flexible alkyl side chains, displaying exceptional regio-, stereo-, and enantioselectivities. Moreover, this transformation exhibits a broad substrate scope and remarkable tolerance toward various functional groups. Theoretical calculations demonstrate that the benzyl group on the ligand is the key to the high enantiocontrol in this transformation. Additionally, we exemplify the practical application of this strategy through the concise synthesis of complex bioactive molecules.

Enantioselective Synthesis of Axially and Centrally Chiral Styrenes via Nickel-Catalyzed Desymmetric Hydrocyanation of Biaryl Dienes

Herein, a highly regio-, enantio-, and diastereoselective nickel-catalyzed desymmetric hydrocyanation of biaryl dienes for the simultaneous construction of axial and central chiralities is presented, which offers a convenient approach to a variety of tirenes containing the union of an axially chiral biaryl and a centrally α-chiral nitrile under mild conditions using a commercially available catalyst. The synthetic utility is highlighted by the development of a novel axially chiral phosphine ligand and biphenyl-based chiral diene ligand and their potential applications in the field of asymmetric catalytic reactions.

Amide-Directed Rhodium-Catalyzed Chain-Walking Hydrothiolation of Internal Alkenes

We developed a rhodium-catalyzed chain-walking hydrothiolation process for internal alkenes, which offers a novel and efficient alternative for C(sp3)-H bond cleavage, while focusing on thiol incorporation. This method exclusively affords N,S-acetals at 36-90% yields. Regioconvergent hydrothiolation significantly improved the effectiveness of this transformation. Preliminary mechanistic investigations revealed that an amide-directing group is essential for regioselective synthesis, underlining its significance in this process.