1,2-H shift in copper-chlorocarbenoid intermediate during CuCl/bpy-promoted stereoselective dechlorination of 2,2,2-trichloroethyl alkyl ethers to (2)-1-alkoxy-2-chloroethenes

摘要

Reaction of 2,2,2-trichloroethyl alkyl ethers with 2 molar equiv of CuCl/bpy in refluxing DCE yielded (2)-1-alkoxy-2-chloroethenes stereoselectively as the major product via 1,2-H shift in copper-chlorocarbenoid intermediate. 2,2,2-Trichloroethyl carboxylates undergo a radical 1,2-acyloxy shift under similar conditions.