Pd-Catalyzed oxidative isomerization of propargylic acetates: highly efficient access to α-acetoxyenones via alkenyl Csp2–O bond-forming reductive elimination from PdIV

Abstract

A Pd(II)/(IV)-catalyzed oxidative isomerization of propargylic acetates developed for the synthesis of polysubstituted alkenyl acetates is described. The reductive elimination of alkenyl Csp²–OAc bonds from Pd^IV intermediates is achieved. Mechanistic studies indicate that the reaction mechanism consists of trans acetoxypalladation of a triple bond, isomerization, oxidative addition with PhI(OAc)₂ and alkenyl C–OAc bond reductive elimination.