Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts

Synthesis of Diarylalkanes by Photoreductive 1,2-Diarylation of Alkenes with Aryl Halides and Cyanoaromatics

We report a visible light-induced photoreductive strategy for three-component diarylation of alkenes with aryl halides and cyanoaromatics. Upon photoredox catalysis and with tertiary alkyl amines as the electron transfer agent, aryl halides selectively undergo halogen atom transfer to generate the aryl radicals and two C(sp2)-C(sp3) bonds between the cabron atoms are created in a radical addition and radical-radical coupling fashion to rapidly assemble diverse functionalized polyarylalkanes with high regio- and chemoselectivity. This method can be applied to broad feedstocks, including terminal alkenes, internal alkenes, aryl iodides, aryl bromides, aryl chlorides, electron-deficient benzonitriles, and isonicotinonitriles.

Ni-Catalyzed Linearizable Cyclization/Coupling with Detachable Silicon-Oxygen Linker: Access to 1,2-Oxasilolanes, 3-Hydroxysilanes and 4-Arylalkanols

We disclose a Ni-catalyzed cyclization/alkylmetal interception reaction in which products are readily linearized to permit regiodefined alkene dicarbofunctionalization. This method offers a convenient route to access 1,2-oxasilolane heterocycles, 3-hydroxysilanes and 4-arylalkanols with the formation of C(sp3)-C(sp3) bonds at primary and secondary alkyl carbon centers. In this reaction, a silicon-oxygen (Si-O) bond functions as a detachable linker that can be delinked with several hydride, alkyl, aryl and vinyl nucleophiles to create profusely functionalized 3-hydroxysilanes. A silicon motif in the cyclic C(sp3)-Si-O construct in 1,2-oxasilolane heterocycles can also be selectively deleted by Pd-catalyzed hydrodesilylation affording Si-ablated linear alcohol products reminiscent of vicinal ethylene dicarbofunctionalization with C(sp3) and C(sp2) carbon sources.

Iron-Mediated Dialkylation of Alkenylarenes with Benzyl Bromides

We disclose a method for the dibenzylation of alkenylarenes with benzyl bromides using iron powder. This reaction generates branched alkyl scaffolds adorned with functionalized aryl rings through the formation of two new C(sp3)-C(sp3) bonds at the vicinal carbons of alkenes. This protocol tolerates electron-rich, electron-neutral, and electron-poor benzyl bromides and alkenylarenes. Mechanistic studies suggest the formation of benzylic radical intermediates as a result of single-electron transfer from the iron, which is intercepted by alkenylarenes.

A free-radical design featuring an intramolecular migration for a synthetically versatile alkyl-(hetero)arylation of simple olefins

A free-radical approach has enabled the development of a synthetically versatile alkyl-(hetero)arylation of olefins. Alkyl and (hetero)aryl groups were added concurrently to a full suite of mono- to tetrasubstituted simple alkenes (i.e., without requiring directing or electronically activating groups) for the first time. Key advances also included the introduction of synthetically diversifiable alkyl groups featuring different degrees of substitution, good diastereocontrol in both cyclic and acyclic settings, the addition of biologically valuable heteroarenes featuring Lewis basic nitrogen atoms as well as simple benzenes, and the generation of either tertiary or quaternary benzylic centers. The synthetic potential of this transformation was demonstrated by leveraging it as the key step in a concise synthesis of oliceridine, a new painkiller that received FDA approval in 2020.

Electrochemical Nickel-Catalyzed 1,2-Diarylation of 1,3-Dienes

Due to the presence of carbon-carbon double bonds, 1,3-dienes exhibit great reactivity. A protocol for the site-selective diarylation of terminal 1,3-dienes is reported here. The transformation is facilitated by the Ni catalyst without the need for additional ligands, utilizing an electrochemical setup. Preliminary results indicate that by introducing chiral ligands moderate enantioselective diarylation products can be obtained. This method affords diversely substituted diarylated products that occur as structural motifs in various natural products.

Nickel-Catalyzed Three-Component Alkylarylation of Alkenyl N-Heteroarenes

A nickel-catalyzed three-component alkylarylation of alkenyl N-heteroarenes with α-bromocarboxylates and aryl boronic acids is reported. The protocol provides a new method to access a variety of N-heteroarene substituted diarylalkanes in moderate to good yields. It features mild reaction conditions, cheap nickel catalyst, readily available substrates, and broad substrate scope.

Nickel-Catalyzed Regioselective Intermolecular Dialkylation of Alkenylarenes: Generation of Two Vicinal C(sp3 )-C(sp3 ) Bonds Across Alkenes

We disclose a Ni-catalyzed regioselective dialkylation reaction of alkenylarenes with α-halocarbonyls and alkylzinc reagents. The reaction produces γ-arylated alkanecarbonyl compounds with the generation of two new C(sp3 )-C(sp3 ) bonds at the vicinal carbons of alkenes. This reaction is effective for the use of primary, secondary and tertiary α-halocarboxylic esters, amides and ketones in conjunction with primary and secondary alkylzinc reagents as the sources of two C(sp3 ) carbons for the dialkylation of terminal and cyclic internal alkenes.

Ligand-Controlled Nickel-Catalyzed Reactions of Benzocyclobutenones with Alkynyltrifluoroborates: Diverse Construction of Polysubstituted Naphthols

Ligand-controlled nickel-catalyzed selective cleavage of the C1-C2 or C1-C8 bond of benzocyclobutenones (BCBs) is reported. The delicate selection of dpppe or PMe₃ as the ligand led to predictably divergent synthesis of a wide range of 1-naphthols and 2-naphthols without C2 and C3 substituents, respectively, from BCBs and potassium alkynyltrifluoroborate, and the increase in the amount of PMe₃ resulted in tandem reaction of 2 equiv of BCB with the borate to afford 3,4,5-trisubstituted 2-naphthols. The fabulous ligand effect resulted in the facile and unique construction of multisubstituted naphthols with well-controlled regioselectivity and a high degree of structural diversity.

Synergistic Li/Li Bimetallic System for the Asymmetric Synthesis of Antituberculosis Drug TBAJ-587

TBAJ-587, an analogue of the antituberculosis drug bedaquiline (BDQ), bearing a diarylquinoline skeleton retains the high bacterial potency, is less toxic, and has a better pharmacokinetic profile than the parent molecule, which has entered phase I clinical trials. In contrast to its fascinating bioactivity, however, the highly efficient synthesis of this molecule is still an unsolved challenge. Herein, the first asymmetric synthesis of TBAJ-587 based on a synergistic Li/Li bimetallic system is reported. The product could be obtained in an excellent yield of 90% and an enantiomeric ratio (er) of 80:20. Furthermore, the reaction could be conducted on a 5 g scale, and the product was obtained with 99.9:0.1 er after a simple recrystallization. The realization of this protocol will greatly aid the demand for clinical drug production.

Directed Asymmetric Nickel-Catalyzed Reductive 1,2-Diarylation of Electronically Unactivated Alkenes

Transition-metal catalyzed intermolecular 1,2-diarylation of electronically unactivated alkenes has emerged as an extensive research topic in organic synthesis. However, most examples are mainly limited to terminal alkenes. Furthermore, transition-metal catalyzed asymmetric 1,2-diarylation of unactivated alkenes still remains unsolved and is a formidable challenge. Herein, we describe a highly efficient directed nickel-catalyzed reductive 1,2-diarylation of unactivated internal alkenes with high diastereoselectivities. More importantly, our further effort towards enantioselective 1,2-diarylation of the unactivated terminal and challenging internal alkenes is achieved, furnishing various polyarylalkanes featuring benzylic stereocenters in high yields and with good to high enantioselectivities and high diastereoselectivities. Interestingly, the generation of cationic Ni-catalyst by adding alkali metal fluoride is the key to increased efficiency of this enantioselective reaction.

Electroreduction Enables Regioselective 1,2-Diarylation of Alkenes with Two Electrophiles

Precisely introducing two similar functional groups into bulk chemical alkenes represents a formidable route to complex molecules. Especially, the selective activation of two electrophiles is in crucial demand, yet challenging for cross-electrophile-coupling. Herein, we demonstrate a redox-mediated electrolysis, in which aryl nitriles are both aryl radical precursors and redox-mediators, enables an intermolecular alkene 1,2-diarylation with a remarkable regioselectivity, thereby avoiding the involvement of transition-metal catalysts. This transformation utilizes cyanoarene radical anions for activating various aryl halides (including iodides, bromides, and even chlorides) and affords 1,2-diarylation adducts in up to 83 % yield and >20 : 1 regioselectivity with more than 80 examples, providing a feasible approach to complex bibenzyl derivatives.

Reductive-Delay Heck 1,1-Diarylation of Terminal Alkenes

Pd-catalyzed chemo- and regiocontrollable 1,1-diarylation of unactivated aliphatic alkenes with two aryl halides was developed. Under the cationic reductive-delay Heck pathway, the first aryl insertion is followed by β-H elimination, while the second aryl insertion is terminated by C-H bond formation.

Dicarbofunctionalizations of an Unactivated Alkene via Photoredox/Nickel Dual Catalysis

1,2-Dicarbofunctionalization of unactivated olefin has been reported under photoredox/nickel dual catalysis. The mildness of the visible-light-mediated reaction allows the use of various alkyl and aryl electrophiles with several sensitive functional groups. The protocol was equally applied for late-stage diversification of drugs and biologically active molecules. Investigations elucidated the importance of photoredox/nickel dual catalysis and α-amino-radical-mediated halogen atom transfer and provided us with the nickel complexes involved in the reaction.

Interception of Nickel Hydride Species and Its Application in Multicomponent Reactions

The hydrogen borrowing strategy is an economical method for the α-functionalization of ketones. While this strategy is extremely advantageous, it does not lend itself to the synthesis of β,β-disubstituted ketones. This can be achieved, if the in situ generated metal hydride can be intercepted with a nucleophilic coupling partner. We present a multicomponent strategy for the coupling of alcohols, ketones, and boronic acids using only 1 mol % nickel catalyst and without the need for added ligands.

Ni-Catalyzed Regio- and Stereoselective Alkylarylation of Unactivated Alkenes in γ,δ-Alkenylketimines

We disclose a Ni-catalyzed vicinal alkylarylation of unactivated alkenes in γ,δ-alkenylketimines with aryl halides and alkylzinc reagents. The reaction produces γ-C(sp3)-branched δ-arylketones with the construction of two new C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds. Electron-deficient alkenes play crucial dual roles as ligands to stabilize reaction intermediates and to increase catalytic rates for the formation of C(sp3)-C(sp3) bonds. This alkene alkylarylation reaction is also effective for secondary alkylzinc reagents and internal alkenes, and proceeds with a complete regio- and stereocontrol, affording products with up to three contiguous all-carbon all-cis secondary stereocenters.

Reactivity of Xantphos-Type Rhodium Complexes Towards SF4 : SF3 Versus SF2 Complex Generation

S-F-bond activation of sulfur tetrafluoride at [Rh(Cl)(tBu xanPOP)] (1; tBu xanPOP=9,9-dimethyl-4,5-bis-(di-tert-butylphosphino)-xanthene) led to the formation of the cationic complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][SF5 ] (2 a) together with trans-[Rh(Cl)(F)2 (tBu xanPOP)] (3) and cis-[Rh(Cl)2 (F)(tBu xanPOP)] (4) which both could also be obtained by the reaction of SF5 Cl with 1. In contrast to that, the conversion of SF4 at the methyl complex [Rh(Me)(tBu xanPOP)] (5) gave the isolable and room-temperature stable cationic λ4 -trifluorosulfanyl complex [Rh(Me)(SF3 )(tBu xanPOP)][SF5 ] (6). Treatment of 6 with the Lewis acids BF3 or AsF5 produced the dicationic difluorosulfanyl complex [Rh(Me)(SF2 )(tBu xanPOP)][BF4 ]2 (8 a) or [Rh(Me)(SF2 )(tBu xanPOP)][AsF6 ]2 (8 b), respectively. Refluorination of 8 a was possible with the use of dimethylamine giving [Rh(Me)(SF3 )(tBu xanPOP)][BF4 ] (9). A reaction of 6 with trichloroisocyanuric acid (TClCA) gave the fluorido complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][Cl] (2 b) together with chloromethane and SF5 Cl.

Catalytic Asymmetric Diarylation of Internal Acyclic Styrenes and Enamides

Enantioselective transformations of olefins are among the most important strategies for the asymmetric synthesis of organic compounds. Chemo-, diastereo-, and stereoselective control of reactions with internal acyclic alkenes for the construction of functionalized acyclic alkanes still remain a persistent challenge. Here, we report a palladium-catalyzed asymmetric regiodivergent Heck-type diarylation of internal acyclic alkenes. The 1,2-diarylation of two accessible acyclic alkenes, cinnamyl carbamates and enamides with diazonium salts and aromatic boronic acids, furnishes products containing vicinal stereogenic centers via the stereospecific formation of carbonyl coordination-assisted transient palladacycles. Moreover, the asymmetric migratory diarylation of enamides enables the formation of incontiguous stereocenters by an interrupted diastereoselective 1,3-chain-walking process. This protocol streamlines access to highly functionalized multisubstituted enantioenriched carbamates and amine derivatives which are embedded in the key biologically active motifs.

Nickel-Catalyzed Intermolecular Asymmetric Addition of Aryl Iodides across Aldehydes

Enantioenriched alcohols comprise much of the framework of organic molecules. Here, we first report that chiral nickel complexes can catalyze the intermolecular enantioselective addition of aryl iodides across aldehydes to provide diverse optically active secondary alcohols using zinc metal as the reducing agent. This method shows a broad substrate scope under mild reaction conditions and precludes the traditional strategy through the pre-generation of organometallic reagents. Mechanistic studies indicate that an in situ formed arylnickel, instead of an arylzinc, adds efficiently to aldehydes, forming a new C-C bond and a chiral nickel alkoxide that may be turned over by zinc powder.

Electrophilic Sulfur Reagent Design Enables Directed syn-Carbosulfenylation of Unactivated Alkenes

A multi-component approach to structurally complex organosulfur products is described via the nickel-catalyzed 1,2-carbosulfenylation of unactivated alkenes with organoboron nucleophiles and tailored organosulfur electrophiles. The key to the development of this transformation is the identification of a modular N-alkyl-N-(arylsulfenyl)arenesulfonamide family of sulfur electrophiles. Tuning the electronic and steric properties of the leaving group in these reagents controls pathway selectivity, favoring three-component coupling and suppressing side reactions, as examined via computational studies. The unique syn-stereoselectivity differs from traditional electrophilic sulfenyl transfer processes involving a thiiranium ion intermediate and arises from the directed arylnickel(I) migratory insertion mechanism, as elucidated through reaction kinetics and control experiments. Reactivity and regioselectivity are facilitated by a collection of monodentate, weakly coordinating native directing groups, including sulfonamides, alcohols, amines, amides, and azaheterocycles.

Nickel-Catalyzed Desymmetric Reductive Cyclization/Coupling of 1,6-Dienes: An Enantioselective Approach to Chiral Tertiary Alcohol

We have developed a nickel-catalyzed desymmetric reductive cyclization/coupling of 1,6-dienes. The reaction provides an efficient method for constructing a chiral tertiary alcohol and a quaternary stereocenter by a single operation. The method has excellent diastereoselectivity and high enantioselectivity, a broad substrate scope, as well as good tolerance of functional groups. Preliminary mechanism studies show that alkyl nickel(I) species are involved in the reaction.

Remote arylalkylation of unactivated alkenes via 6- or 7-membered nickelacycles with excellent diastereofidelity

We developed a nickel-catalyzed remote arylalkylation of unactivated alkenes via kinetically and thermodynamically disfavored 6- and 7-membered nickelacycles.

Palladium-Catalyzed Difunctionalization of Alkenes by Relay Coupling with Propargylic Pyridines: Synthesis of Indolizine and Indolizinone-Containing Bisheterocycles

Palladium-catalyzed arylation/heteroarylation of aryl halide-tethered alkenes with propargylic pyridines has been established, which provides direct and efficient access to various oxindole, azaoxindole, dihydrobenzopyran, indole, and benzofuran-linked indolizines in good yields with a broad substrate scope and high functional group tolerance. This process enables the formation of one C-N and two C-C bonds in a single operation through an intramolecular carbopalladation and cycloisomerization sequence. Furthermore, an indolizinone-linked bisheterocyclic framework containing indole and benzofuran could be synthesized conveniently from tertiary propargylic alcohols involving methyl or phenyl migration.

Directing-group-free catalytic dicarbofunctionalization of unactivated alkenes

In the absence of directing auxiliaries, the catalytic addition of carbogenic groups to unactivated alkenes with control of regioselectivity remains an ongoing challenge in organic chemistry. Here we describe a directing-group-free, nickel-catalysed strategy that couples a broad array of unactivated and activated olefins with aryl-substituted triflates and organometallic nucleophiles to afford diarylation adducts in either regioisomeric form, in up to 93% yield and >98% site selectivity. By switching the reagents involved, the present strategy may be extended to other classes of dicarbofunctionalization reactions. Mechanistic and computational investigations offer insights into the origin of the observed regiochemical outcome and the utility of the method is highlighted through the concise syntheses of biologically active molecules. The catalyst control principles reported are expected to advance efforts towards the development of general site-selective alkene functionalizations, removing the requirement for neighbouring activating groups.

Fe-Catalyzed dicarbofunctionalization of electron-rich alkenes with Grignard reagents and (fluoro)alkyl halides

An iron-catalyzed regioselective dicarbofunctionalization of electron-rich alkenes is described. In particular, aryl- and alkyl vinyl ethers are used as effective linchpins to couple alkyl or (fluoro)alkyl halides and sp2-hybridized Grignard nucleophiles. Preliminary results demonstrate the ability to engage thioethers as linchpins and control enantioselectivity in these transformations, an area which is largely unexplored in iron-catalyzed three-component cross-coupling reactions.

Directed Nickel-Catalyzed Diastereoselective Reductive Difunctionalization of Alkenyl Amines

We report herein an intermolecular syn-arylalkylation and alkenylalkylation of alkenyl amines with two different organohalides (iodides and bromides) using Ni(II) catalyst. The cleavable bidentate quinolinamide is utilized after extensive directing group screening to enable olefin difunctionalization with high levels of regio-, chemo-, and diastereocontrol. This general and practical protocol is compatible with α- or β-substituted terminal alkenes and internal alkenes, providing rapid access to branched aliphatic amines bearing two skipped and vicinal stereocenters with high diastereoselectivities that would otherwise be difficult to synthesize.

Regioselective Hydroalkylation of Vinylarenes by Cooperative Cu and Ni Catalysis

Disclosed here is a dual copper and nickel catalytic system with a silyl hydride source for promoting the linear selective hydroalkylation of vinylarenes. This carbon-carbon bond-forming protocol is applied to couple a variety of functionalized vinylarenes with alkyl halides applying a nickel(II) NNN pincer complex in the presence of an NHC-ligated copper catalyst. This combination allows for a 1 mol % loading of the nickel catalyst leading to turnover numbers of up to 72. Over 40 examples are presented, including applications for pharmaceutical diversification. Labeling experiments demonstrated the regioselectivity of the reaction and revealed that the copper catalyst plays a crucial role in enhancing the rate for formation of the reactive linear alkyl nickel complex. Overall, the presented work provides a complimentary approach for hydroalkylation reactions, whilst providing a preliminary mechanistic understanding of the cooperativity between the copper and nickel complexes.

Ni-Catalyzed Arylbenzylation of Alkenylarenes: Kinetic Studies Reveal Autocatalysis by ZnX2 *

We report a Ni-catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3-triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate-limiting single-electron-transfer process and is autocatalyzed by in-situ-generated ZnX2 . The reaction rate is amplified by a factor of three through autocatalysis upon addition of ZnX2 .

Transition Metal (Ni, Cu, Pd)-Catalyzed Alkene Dicarbofunctionalization Reactions

Recently, alkene dicarbofunctionalization, i.e., the powerful organic synthesis method of alkene difunctionalization with two carbon sources, emerged as a formidable reaction with immense promise to synthesize complex molecules expeditiously from simple chemicals. This reaction is generally achieved with transition metals (TMs) through interception by carbon sources of an alkylmetal [β-H-C(sp³)-[M]] species, a key intermediate prone to undergo rapid β-H elimination. Related prior reports, since Paolo Chiusoli and Catellani's work in 1982 [ Tetrahedron Lett. 1982, 23, 4517], have used bicyclic and disubstituted terminal alkenes, wherein β-H elimination is avoided by geometric restriction or complete lack of β-H's. With reasoning that β-H-C(sp³)-[M] intermediates could be rendered amenable to interception with the use of first row late TMs and formation of coordination-assisted transient metallacycles, these two strategies were implemented to address the β-H elimination problem in alkene dicarbofunctionalization reactions.Because first row late TMs catalyze C(sp³)-C(sp³) coupling, Cu and Ni were anticipated to impart sufficient stability to β-H-C(sp³)-[M] intermediates, generated catalytically upon alkene carbometalation, for their subsequent interception by carbon electrophiles/nucleophiles in three-component reactions. Additionally, such an innate property could enable alkene difunctionalization with carbon coupling partners through entropically driven cyclization/coupling reactions. The cyclometalation concept to stabilize intractable β-H-C(sp³)-[M] intermediates was hypothesized when three-component reactions were performed. The idea of cyclometalation to curtail β-H elimination is founded upon Whitesides's [ J. Am. Chem. Soc. 1976, 98, 6521] observation that metallacycles undergo β-H elimination much slower than acyclic alkylmetals.In this Account, examples of alkene dicarbofunctionalization reactions demonstrate that Cu and Ni catalysts could enable cyclization/coupling of alkenylzinc reagents, alkyl halides, and aryl halides to afford complex carbo- and heterocycles. In addition, forming coordination-assisted transient nickellacycles enabled regioselective performance of three-component dicarbofunctionalization of various alkenyl compounds. In situ reaction of [M]-H with alkenes generated after β-H elimination induced an unprecedented metallacycle contraction process, in which six-membered metal-containing rings shrank to five-membered cycles, allowing creation of new carbon-carbon bonds at allylic (1,3) positions. Applications of these regioselective alkene dicarbofunctionalization reactions are discussed.

Nickel-Catalyzed Regioselective Alkenylarylation of γ,δ-Alkenyl Ketones via Carbonyl Coordination

We disclose a nickel-catalyzed reaction, which enabled us to difunctionalize unactivated γ,δ-alkenes in ketones with alkenyl triflates and arylboronic esters. The reaction was made feasible by the use of 5-chloro-8-hydroxyquinoline as a ligand along with NiBr2 ⋅DME as a catalyst and LiOtBu as base. The reaction proceeded with a wide range of cyclic, acyclic, endocyclic and exocyclic alkenyl ketones, and electron-rich and electron-deficient arylboronate esters. The reaction also worked with both cyclic and acyclic alkenyl triflates. Control experiments indicate that carbonyl coordination is required for the reaction to proceed.

Ni-Catalyzed 1,2-Diarylation of Alkenyl Ketones: A Comparative Study of Carbonyl-Directed Reaction Systems

A nickel-catalyzed 1,2-diarylation of alkenyl ketones with aryl iodides and arylboronic esters is reported. Ketones with a variety of substituents serve as effective directing groups, offering high levels of regiocontrol. A representative product is diversified into a wide range of useful products that are not readily accessible via existing 1,2-diarylation reactions. Preliminary mechanistic studies shed light on the binding mode of the substrate, and Hammett analysis reveals the effect of electronic factors on initial rates.

Three-Component Alkene Difunctionalization by Direct and Selective Activation of Aliphatic C-H Bonds

Catalytic alkene difunctionalization is a powerful strategy for the rapid assembly of complex molecules and has wide range of applications in synthetic chemistry. Despite significant progress, a compelling challenge that still needs to be solved is the installation of highly functionalized C(sp³ )-hybridized centers without requiring pre-activated substrates. We herein report that inexpensive and easy-to-synthesize decatungstate photo-HAT, in combination with nickel catalysis, provides a versatile platform for three-component alkene difunctionalization through direct and selective activation of aliphatic C-H bonds. Compared with previous studies, the significant advantages of this strategy are that the most abundant hydrocarbons are used as feedstocks, and various highly functionalized tertiary, secondary, and primary C(sp³ )-hybrid centers can be easily installed. The practicability of this strategy is demonstrated in the selective late-stage functionalization of natural products and the concise synthesis of pharmaceutically relevant molecules including Piragliatin.

Mechanism-Based Design of an Amide-Directed Ni-Catalyzed Arylboration of Cyclopentene Derivatives

A method for amide-directed Ni-catalyzed diastereoselective arylboration of cyclopentenes is disclosed. The reaction allows for the synthesis of sterically congested cyclopentane scaffolds that contain an easily derivatized boronic ester and amide functional handles. The nature of the amide directing group and its influence on the reaction outcome are investigated and ultimately reflect a predictably selective reaction based on the solvent and base counterion.