Silver or Copper Triflate-Catalyzed Amination of Silyl Enol Ethers

Amination of silyl enol ethers with azo diester compounds proceeded smoothly in the presence of a catalytic amount of AgOTf or Cu(OTf)2. Various types of silyl enol ethers reacted smoothly under these conditions and AgOTf gave better yields than Cu(OTf)2 in most cases.