Water-Triggered, Counter-Anion-Controlled, and Silver−Phosphines Complex-Catalyzed Stereoselective Cascade Alkynylation/Cyclization of Terminal Alkynes with Salicylaldehydes

Abstract

A highly efficient alkynylation-cyclization of terminal alkynes with salicylaldehydes leading to substituted 2,3-dihydrobenzofuran-3-ol derivatives was developed by using Cy(3)P-silver complex as catalyst in water. Counter anions in the silver complex proved to be the key factor to Z/E stereoselectivity control. Aurones can also be obtained effectively from the cascade reaction followed by oxidation without further purification.