Nickel-Catalyzed Cross-Electrophile Coupling Reactions between Allylic Acetates and gem-Difluorovinyl Tosylate

Abstract

A nickel-catalyzed cross-electrophile coupling of allylic acetates and gem-difluorovinyl tosylate is presented, which first achieves allylic gemdifluoroolefins via C(sp 3 )−C(sp 2 ) cross-electrophile coupling. In addition, this protocol was performed under mild reaction conditions, affording a variety of allylic gem-difluorovinyl arenes in moderate to good yields. Moreover, both linear and branched allylic acetate could produce a linear cross-coupling product exclusively. Mechanistic studies reveal that the reaction involves two different Ni(0)/Ni(II) catalytic cycles.

Nickel‐Catalyzed Unsymmetrical Bis‐Allylation of Alkynes

“…Notably, by choosing proper catalyst, the chemoselective hydrogenation was also a touchable task. For example, with the reactive Pd/C as catalyst, the 4 aa could be hydrogenated completely to deliver product 16 in 85 % yield [25] . In contrast, under ruthenium catalysis, hydrogenation could be precisely regulated at the terminal alkene bond and generated alkylated product 17 in 78 % yield [26]…”

Synthesis of gem-Difluorinated 1,4-Dienes via Nickel-Catalyzed Three-Component Coupling of (Trifluoromethyl)alkenes, Alkynes, and Organoboronic Acids

“…Therefore, it is of great significance and interest to exploit methods for the efficient and selective synthesis of functionalized gem- difluorinated 1,4-dienes. In recent years, great efforts have been devoted to constructing such skeletons, typically including cross-coupling of 2,2-difluorovinylzinc reagents and allylic bromides, reductive coupling of gem -difluorovinyl tosylate with allylic acetates or gem -difluorinated cyclopropanes, and hydrodifluoroallylation of terminal alkynes . Despite these remarkable advances, it is highly in demand to develop new catalytic methods for the diverse synthesis of gem- difluorinated 1,4-dienes from easily available starting materials.…”