Reagent-controlled regiodivergence in the [3,3]-sigmatropic rearrangement of N-(acyloxy)enamides

Abstract

A regiodivergent [3,3]-sigmatropic rearrangement of N-(acyloxy)enamides has been developed. The regioselectivity of the rearrangement based on the N–O bond cleavage was complementarily controlled by changing reaction conditions. The treatment of enamides with LiHMDS afforded enamido carboxylic acid via C–C bond formation, while the reaction with 2,4,6-collidine under thermal conditions afforded an enamido ester via C–O bond formation.