Photoassisted Cobalt-Catalyzed Asymmetric Reductive Grignard-Type Addition of Aryl Iodides

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(18), С. 8347 - 8354

Опубликована: Апрель 28, 2022

Grignard addition is one of the most important methods used for syntheses alcohol compounds and has been known over a hundred years. However, research on asymmetric catalysis relies use organometallic nucleophiles. Here, we report first visible-light-induced cobalt-catalyzed reductive Grignard-type synthesizing chiral benzyl alcohols (>50 examples, up to 99% yield, ee). This methodology advantages mild reaction conditions, good functionality tolerance, excellent enantiocontrol, avoidance mass metal wastes, precious catalysts. Kinetic realization studies suggested that migratory insertion an aryl cobalt species into aldehyde was rate-determining step reaction.

Язык: Английский

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Catalytic multicomponent reaction involving a ketyl-type radical

Nature Synthesis, Год журнала: 2022, Номер 1(6), С. 464 - 474

Опубликована: Июнь 13, 2022

Язык: Английский

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Merging of Light/Dark Palladium Catalytic Cycles Enables Multicomponent Tandem Alkyl Heck/Tsuji–Trost Homologative Amination Reaction toward Allylic Amines

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(33), С. 18497 - 18505

Опубликована: Авг. 9, 2023

A visible light-induced palladium-catalyzed homologative three-component synthesis of allylic amines has been developed. This protocol proceeds

Язык: Английский

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Phenanthroline-Initiated Anti-selective Hydrosulfonylation of Unactivated Alkynes with Sulfonyl Chlorides

ACS Catalysis, Год журнала: 2023, Номер 13(10), С. 6983 - 6993

Опубликована: Май 8, 2023

A simple and general method for anti-selective hydrosulfonylation of unactivated alkynes with sulfonyl chlorides in the presence a catalytic amount phenanthroline-based Lewis base (Me3Si)3SiH as hydrogen atom donor has been developed. The protocol proceeds efficiently under mild metal-free conditions, delivering diverse set (Z)-vinyl sulfones high stereoselectivity. Additionally, displays excellent functional-group compatibility can be applied to late-stage modifications complex drugs their derivatives. Experimental density functional theory studies unveiled that key transformation's success is employment base, which interacts form halogen-bond accelerates cleavage S–Cl bonds irradiation visible light.

Язык: Английский

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Strategies and Mechanisms of First-Row Transition Metal-Regulated Radical C–H Functionalization

Chemical Reviews, Год журнала: 2024, Номер 124(17), С. 10192 - 10280

Опубликована: Авг. 8, 2024

Radical C–H functionalization represents a useful means of streamlining synthetic routes by avoiding substrate preactivation and allowing access to target molecules in fewer steps. The first-row transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu) are Earth-abundant can be employed regulate radical functionalization. use such is desirable because the diverse interaction modes between metal complexes species including addition center, ligand complexes, substitution single-electron transfer radicals hydrogen atom noncovalent complexes. Such interactions could improve reactivity, diversity, selectivity transformations allow for more challenging reactions. This review examines achievements this promising area over past decade, with focus on state-of-the-art while also discussing existing limitations enormous potential high-value regulated these metals. aim provide reader detailed account strategies mechanisms associated

Язык: Английский

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Enantioselective Directed Nickel-Catalyzed Three-Component Reductive Arylalkylation of Alkenes via the Carbometalation/Radical Cross-Coupling Sequence

ACS Catalysis, Год журнала: 2024, Номер 14(7), С. 4395 - 4406

Опубликована: Март 8, 2024

Asymmetric reductive three-component arylalkylation of alkenes via the radical relay method has been well established, while asymmetric migratory insertion strategy remains unexplored. We report enantioselective nickel-catalyzed cross-electrophile with aryl- and alkyl halides an integrated Heck carbometalation/radical cross-coupling sequence. This protocol employing a chiral Ni/PHOX catalytic system allows terminal internal to successfully engage exquisite control regio-, chemo-, stereoselectivity. More importantly, this undergoes regio- arylnickelation followed by Csp3–Csp3 elimination, thus exhibiting reverse regioselectivity method. Mild reaction conditions exceptional functional group tolerance facilitate method's compatibility bioactive motifs modular synthesis biologically active compounds. The experiments density theory calculations provide insights into mechanism origin stereoselectivity, hemilabile nature PHOX ligand is critical for achieving arylalkylation.

Язык: Английский

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Unlocking carbene reactivity by metallaphotoredox α-elimination

Nature, Год журнала: 2024, Номер 631(8022), С. 789 - 795

Опубликована: Июнь 6, 2024

Язык: Английский

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Nickel-Catalyzed Defluorinative Coupling of Aliphatic Aldehydes with Trifluoromethyl Alkenes

ACS Catalysis, Год журнала: 2022, Номер 12(4), С. 2463 - 2471

Опубликована: Фев. 3, 2022

A simple procedure is reported for the nickel-catalyzed defluorinative alkylation of unactivated aliphatic aldehydes. The process involves catalytic reductive union trifluoromethyl alkenes with aldehydes using a nickel complex 6,6'-disubstituted bipyridine ligand zinc metal as terminal reductant. protocol distinguished by its broad substrate scope, mild conditions, and setup. Reaction outcomes are consistent intermediacy an α-silyloxy(alkyl)nickel intermediate generated low-valent catalyst, silyl electrophile, aldehyde substrate. Mechanistic findings cyclopropanecarboxaldehyde provide insights into nature reactive intermediates illustrate fundamental reactivity differences that governed subtle changes in structure.

Язык: Английский

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Reductive Cross‐Coupling of α‐Oxy Halides Enabled by Thermal Catalysis, Photocatalysis, Electrocatalysis, or Mechanochemistry

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(34)

Опубликована: Июль 11, 2022

Herein, we report a reductive cross-coupling reaction of α-oxy halides, simply generated from aldehydes, with series C(sp2 )- and C(sp)-electrophiles. A wide range aryl heteroatom vinyl bromides, alkynyl acyl chlorides react unhindered hindered aldehyde-derived halides by providing protected alcohols as well α-hydroxy ketones. Noteworthy, the couplings are achieved not only through thermal catalysis use metal reductants but also photocatalysis, electrochemistry, mechanochemistry. The unrestricted interchange four strategies indicates their underlying mechanistic similarities. generation NiI intermediate is proposed to be key point for ketyl radical formation via single-electron transfer (SET) event, which was rationalized an array control experiments density functional theory (DFT) calculations.

Язык: Английский

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Kinetics of a Ni/Ir-Photocatalyzed Coupling of ArBr with RBr: Intermediacy of ArNi^II(L)Br and Rate/Selectivity Factors

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(33), С. 15372 - 15382

Опубликована: Авг. 15, 2022

The Ni/Ir-photocatalyzed coupling of an aryl bromide (ArBr) with alkyl (RBr) has been analyzed using in situ LED-19F NMR spectroscopy. Four components (light, [ArBr], [Ni], [Ir]) are found to control the rate ArBr consumption, but not product selectivity, while two ([(TMS)3SiH], [RBr]) independently rate. A major resting state nickel identified as ArNiII(L)Br, and 13C-isotopic entrainment is used show that complex undergoes Ir-photocatalyzed conversion products (Ar-R, Ar-H, Ar-solvent) competition release ArBr. range competing absorption quenching effects lead correlations between Ir Ni catalyst loadings reaction Differences Ir/Ni Beer-Lambert profiles allow be increased by use a shorter-wavelength light source without compromising selectivity. minimal kinetic model for process allows simulation provides insights optimization these processes laboratory.

Язык: Английский

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