Synthesis of alkynamides through reaction of alkyl- or aryl-substituted alkynylaluminums with isocyanates

Abstract

An efficient and facile method for the preparation of alkynamides through Et3N-catalyzed alumination of alkyl- or aryl-substituted terminal alkynes with AlMe3and sequential nucleophilic addition ofin situgenerated alkynylaluminums to isocyanates is described. This method has the merits of using readily available isocyanates and monosubstituted alkynes, easy access to organoaluminums, short reaction times, and high efficiency. A gram-scale synthesis of the desired alkynamide and its application to the formation of α-methylene-β-lactams demonstrates the synthetic utility of this method. © The Royal Society of Chemistry 2021.