Enantio‐ and Regioselective NiH‐Catalyzed Reductive Hydroarylation of Vinylarenes with Aryl Iodides

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(48), С. 21530 - 21534

Опубликована: Авг. 28, 2020

Abstract A highly enantio‐ and regioselective hydroarylation process of vinylarenes with aryl halides has been developed using a NiH catalyst new chiral bis imidazoline ligand. broad range structurally diverse, enantioenriched 1,1‐diarylalkanes, structure found in number biologically active molecules, have obtained excellent yields enantioselectivities under extremely mild conditions.

Язык: Английский

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NiH‐Catalyzed Migratory Defluorinative Olefin Cross‐Coupling: Trifluoromethyl‐Substituted Alkenes as Acceptor Olefins to Form gem‐Difluoroalkenes

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(13), С. 5398 - 5402

Опубликована: Янв. 17, 2020

We report a NiH-catalyzed migratory defluorinative coupling between two electronically differentiated olefins. A broad range of unactivated donor olefins can be joined directly to acceptor containing an electron-deficient trifluoromethyl substituent in both intra- and intermolecular fashion form gem-difluoroalkenes. This shows site- chemoselectivity under mild conditions, with the formation tertiary or quaternary carbon center.

Язык: Английский

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Ligand‐Controlled Regiodivergent Hydroalkylation of Pyrrolines

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(51), С. 18519 - 18523

Опубликована: Окт. 23, 2019

Abstract Nickel hydride (NiH) catalyzed hydrocarbonation has emerged as an efficient approach to construct new C−C bonds containing at least one C(sp 3 ) center. However, the regioselectivity of this reaction is by far dictated substrates. Described here a strategy achieve two different regioselectivites hydroalkylation same substrates using ligand control. This enables first regiodivergent 3‐pyrrolines, yielding both 2‐ and 3‐alkylated pyrrolidines, valuable synthetic intermediates common motifs in many bioactive molecules. method demonstrates broad scope high functional‐group tolerance, can be applied late‐stage functionalizations.

Язык: Английский

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Nickel-Catalyzed Multicomponent Coupling: Synthesis of α-Chiral Ketones by Reductive Hydrocarbonylation of Alkenes

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(35), С. 14089 - 14096

Опубликована: Авг. 26, 2021

A nickel-catalyzed, multicomponent regio- and enantioselective coupling via sequential hydroformylation carbonylation from readily available starting materials has been developed. This modular hydrofunctionalization strategy enables the straightforward reductive hydrocarbonylation of a broad range unactivated alkenes to produce wide variety unsymmetrical dialkyl ketones bearing functionalized α-stereocenter, including enantioenriched chiral α-aryl α-amino ketones. It uses bisoxazoline as ligand, silane reductant, chloroformate safe CO source, racemic secondary benzyl chloride or an N-hydroxyphthalimide (NHP) ester protected acid alkylation reagent. The benign nature this process renders method suitable for late-stage functionalization complex molecules.

Язык: Английский

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Enantioselective Nickel‐Catalyzed Migratory Hydrocyanation of Nonconjugated Dienes

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(48), С. 21436 - 21441

Опубликована: Авг. 12, 2020

Abstract Metal‐catalyzed chain‐walking reactions have recently emerged as a powerful strategy to functionalize remote positions in organic molecules. However, protocol for nonconjugated dienes remains scarcely reported, and developments are currently ongoing. In this Communication, nickel‐catalyzed asymmetric hydrocyanation of involving process is demonstrated. The reaction exhibits excellent regio‐ chemoselectivity, wide range substrates were tolerated, delivering the products high yields enantioselectivities. Deuterium‐labeling experiments support process, which involves an iterative β‐H elimination reinsertion processes. Gram‐scale synthesis, regioconvergent experiments, downstream transformations gave further insights into potential transformation.

Язык: Английский

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Ligand‐Enabled Nickel‐Catalyzed Redox‐Relay Migratory Hydroarylation of Alkenes with Arylborons

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(23), С. 9186 - 9191

Опубликована: Март 6, 2020

Abstract A redox‐relay migratory hydroarylation of isomeric mixtures olefins with arylboronic acids catalyzed by nickel complexes bearing diamine ligands is described. range structurally diverse 1,1‐diarylalkanes, including those containing a 1,1‐diarylated quaternary carbon, were obtained in excellent yields and high regioselectivity. Preliminary experimental evidence supports the proposed non‐dissociated chainwalking aryl‐nickel(II)‐hydride species along alkyl chain alkenes before selective reductive elimination at benzylic position. catalyst loading as low 0.5 mol % proved to be sufficient large‐scale synthesis while retaining reactivity, highlighting practical value this transformation.

Язык: Английский

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Migratory functionalization of unactivated alkyl bromides for construction of all-carbon quaternary centers via transposed tert-C-radicals

Nature Communications, Год журнала: 2020, Номер 11(1)

Опубликована: Сен. 25, 2020

Abstract Despite remarkable recent advances in transition-metal-catalyzed C(sp 3 )−C cross-coupling reactions, there remain challenging bond formations. One class of such reactions include the formation tertiary -C(sp bonds, presumably due to unfavorable steric interactions and competing isomerizations alkyl metal intermediates. Reported herein is a Ni-catalyzed migratory 3,3-difluoroallylation unactivated bromides at remote centers. This approach enables facile construction otherwise difficult prepare all-carbon quaternary Key success this transformation an unusual functionalization via chain walking most sterically hindered ) center substrate. Preliminary mechanistic radical trapping studies with primary suggest unique mode C-radical generation through chain-walking followed by Ni–C homolysis. strategy complementary existing coupling protocols tert -alkyl organometallic or halide reagents, it expedient centers from easily available starting materials.

Язык: Английский

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Enantioselective NiH‐Catalyzed Reductive Hydrofunctionalization of Alkenes

Chinese Journal of Chemistry, Год журнала: 2021, Номер 40(5), С. 651 - 661

Опубликована: Дек. 3, 2021

Comprehensive Summary Enantioselective NiH‐catalyzed reductive hydrofunctionalization of olefins has attracted much attention in recent years. Using simple chiral ligands, a wide array functionalized and electrophiles can undergo diverse transformations to afford hydrofunctionalized products, regio‐ enantioselectively. These processes avoid the prior preparation organometallic reagents, construct stereogenic center at carbon originating either from olefin or electrophile. This review discusses background, major progress mechanistic investigations this reaction.

Язык: Английский

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Versatile cobalt-catalyzed regioselective chain-walking double hydroboration of 1,n-dienes to access gem-bis(boryl)alkanes

Nature Communications, Год журнала: 2020, Номер 11(1)

Опубликована: Фев. 7, 2020

Abstract Double hydroboration of dienes is the addition a hydrogen and boryl group to two double bonds diene molecule represents straightforward effective protocol prepare synthetically versatile bis(boryl)alkanes, provided that this reaction occurs selectively. However, can potentially yield several isomeric organoboron products, it still remains challenge control regioselectivity reaction, which allows selective production single product, in particular, for broad scope dienes. By employing readily available cobalt catalyst, here we show yields useful gem -bis(boryl)alkanes with excellent regioselectivity. In addition, encompasses wide range conjugated non-conjugated Furthermore, mechanistic studies indicate cobalt-catalyzed through boryl-directed chain-walking alkenylboronates generated from anti -Markovnikov 1,2-hydroboration 1,n-diene.

Язык: Английский

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Dual Ni/photoredox-catalyzed asymmetric cross-coupling to access chiral benzylic boronic esters

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Март 12, 2021

Abstract The flourishing Ni/photoredox-catalyzed asymmetric couplings typically rely on redox-neutral reactions. In this work, we report a reductive cross-coupling of aryl iodides and α-chloroboranes under dual catalytic regime to further enrich the metallaphotoredox chemistry. This approach proceeds mild conditions (visible light, ambient temperature, no strong base) access versatile benzylic boronic esters with good functional group tolerance excellent enantioselectivities.

Язык: Английский

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