Transition-metal-catalyzed C–H allylation reactions

Chem, Journal Year: 2020, Volume and Issue: 7(3), P. 555 - 605

Published: Nov. 13, 2020

Language: Английский

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Catalytic Allylation of Aldehydes Using Unactivated Alkenes

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(28), P. 12374 - 12381

Published: July 1, 2020

Simple feedstock organic molecules, especially alkenes, are attractive starting materials in synthesis because of their wide availability. Direct utilization such bulk, inert molecules for practical and selective chemical reactions, however, remains limited. Herein, we developed a ternary hybrid catalyst system comprising photoredox catalyst, hydrogen-atom-transfer chromium complex enabling catalytic allylation aldehydes with simple including lower alkenes. The reaction proceeded under visible-light irradiation at room temperature high functional group tolerance. was extended to an asymmetric variant by employing chiral catalyst.

Language: Английский

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Branch-Selective Addition of Unactivated Olefins into Imines and Aldehydes

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(49), P. 16976 - 16981

Published: Nov. 21, 2018

Radical hydrofunctionalization occurs with ease using metal-hydride hydrogen atom transfer (MHAT) catalysis to couple alkenes and competent radicalophilic electrophiles. Traditional two-electron electrophiles have remained unreactive. Herein we report the reductive coupling of electronically unbiased olefins imines aldehydes. Iron allows addition alkyl-substituted into through intermediacy free radicals, whereas a combination catalytic Co(Salt-Bu,t-Bu) chromium salts enables branch-selective aldehydes formation putative alkyl intermediate.

Language: Английский

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1,2-Amino Alcohols via Cr/Photoredox Dual-Catalyzed Addition of α-Amino Carbanion Equivalents to Carbonyls

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(5), P. 2168 - 2174

Published: Jan. 10, 2020

Herein, we report the synthesis of protected 1,2-amino alcohols starting from carbonyl compounds and α-silyl amines. The reaction is enabled by a Cr/photoredox dual catalytic system that allows in situ generation α-amino carbanion equivalents which act as nucleophiles. unique nature this was demonstrated through aminoalkylation ketones an acyl silane, classes electrophiles were previously unreactive toward addition alkyl-Cr reagents. Overall, broadens scope Cr-mediated alkylations discloses underexplored retrosynthetic strategy for alcohols.

Language: Английский

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Direct C–H Arylation of Aldehydes by Merging Photocatalyzed Hydrogen Atom Transfer with Palladium Catalysis

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(14), P. 7543 - 7551

Published: June 11, 2020

Herein, we report that merging palladium catalysis with hydrogen atom transfer (HAT) photocatalysis enabled direct arylations and alkenylations of aldehyde C–H bonds, facilitating visible light-catalyzed construction a variety ketones. Tetrabutylammonium decatungstate anthraquinone were found to act as synergistic HAT photocatalysts. Density functional theory calculations suggested Pd0–PdII–PdIII–PdI–Pd0 pathway revealed regeneration the Pd0 catalyst photocatalyst occurs simultaneously in presence KHCO3. This features low energy barrier, promoting efficient coupling catalytic cycle photocatalytic cycle. The work reported herein suggests great promise for further applications palladium-catalyzed cross-coupling C-H functionalization reactions be successful.

Language: Английский

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