The Michael Reaction of Various Quinones with Silyl Enol Ethers. A Facile Method for the Preparation of Benzofuran and Indole Derivatives

Abstract
In the presence of a catalytic amount of trityl perchlorate, 1,4-benzoquinone, quinone monoimides, or imidoquinones react with silyl enol ethers to produce the corresponding benzofuran or indole derivatives in high yields via the corresponding Michael adducts.