Nickel‐Catalyzed Reductive Allyl−Aryl Cross‐Electrophile Coupling via Allylic C−F Bond Activation

Abstract

Nickel-catalyzed reductive cross-coupling of allylic difluorides with aryl iodides was achieved via allylic CÀ F bond activation. Based on this protocol, a series of γ-arylated monofluoroalkenes were synthesized in moderate to high yields with high Z-selectivities. Mechanistic studies suggest that the CÀ I bonds of the aryl iodides and the CÀ F bonds of the allylic difluorides were cleaved via oxidative addition and β-fluorine elimination, respectively, where the oxidative addition of less reactive CÀ F bonds was avoided to permit their transformation.

Stereospecific Nickel-Catalyzed Cross-Electrophile Coupling Reaction of Alkyl Mesylates and Allylic Difluorides to Access Enantioenriched Vinyl Fluoride-Substituted Cyclopropanes

“…Coupling reactions that use allylic geminal difluorides are less developed. , Hayashi and co-workers have developed an enantioselective Suzuki XC reaction of allylic difluorides for the synthesis of complex α-fluoro,α,β-unsaturated carbonyls (Scheme b) . To our knowledge, XEC reactions of allylic difluorides have not been established . We were interested in developing a new XEC reaction of allylic difluorides, building on our strategies for intramolecular XEC reactions of alkyl mesylates and alkyl fluorides, to access cyclopropanes bearing vinyl fluoride motifs.…”

“… 10 To our knowledge, XEC reactions of allylic difluorides have not been established. 11 We were interested in developing a new XEC reaction of allylic difluorides, building on our strategies for intramolecular XEC reactions of alkyl mesylates and alkyl fluorides, 12 to access cyclopropanes bearing vinyl fluoride motifs. In this manuscript, we describe the development of an enantiospecific intramolecular XEC reaction of allylic gem -difluorides and alkyl mesylates to access enantioenriched vinyl fluoride-substituted cyclopropanes ( Scheme 1 c).…”