Redox-Neutral Copper(II) Carboxylate Catalyzed α-AIkynylation of Amines

摘要

Propargylic amines represent important building blocks, and compounds of this class (e.g., 1) are readily assembled by three-component reactions of amines, aldehydes, and alkynes, frequently referred to as A~3 reactions [Eq. (1)]. Methods that enable direct access to the ring-substituted isomers 2 are much more limited [see Eq. (2)]. As part of a program to develop redox-neutral reactions of broad utility, we recently reported an α-amino acid based decar-boxylative three-component coupling strategy to access ring-substituted propargylic amines such as 2 [Eq. (2)] . A nearly identical approach was also reported by Li et al. Replacement of the a-amino acid with a simple amine would represent a significant advance [Eq. (3)]. Herein we report the first examples of this elusive transformation.