Photocatalytic gem-Difluoroolefination Reactions by a Formal C-C Coupling/Defluorination Reaction with Diazoacetates.

ABSTRACT: The photolysis of diazoalkanes to conduct singlet carbene transfer reactions of colored diazoalkanes has recently attracted significant interest in organic synthesis. Herein, we describe a photocatalytic approach that allows the access of triplet carbene intermediates via energy transfer to conduct highly efficient gem-difluoroolefination reactions with α-trifluoromethyl styrenes. The use of a tertiary amines proved pivotal to unlock this unusual reaction pathway and to prevent undesired cyclopropanation pathways. The amine further facilitates the ultimate abstraction of fluoride to yield gem-difluoroolefins (43 examples, up to 88 % yield), which is supported by experimental and theoretical mechanistic studies. We explored this synthesis method with a broad substrate scope, ranging from si

SUBMITTER: Li F 

PROVIDER: S-EPMC9300101 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature