Cobalt(II)‐Catalyzed Electrophilic Alkynylation of 1,3‐Dicarbonyl Compounds To Form Polysubstituted Furans <i>via</i> π–π Activation

Abstract

Abstract Polysubstituted furans were obtained with excellent yields via the electrophilic alkynylation of 1,3‐dicarbonyl compoundsws with phenyl‐ or ester‐substituted brominated alkynes. The reaction is catalyzed by the inexpensive and readily available catalyst, cobalt(II) chloride, and has a wide substrate scope. The C( sp )C( sp 3 ) coupling occurs under mild conditions with short reaction times and does not require an inert atmosphere or ligands. It is proposed that the reaction proceeds through a chelation complex of cobalt(II) with the deprotonated 1,3‐dicarbonyl compound. magnified image