Cu(I)-catalyzed cascade reaction of N-tosylhydrazones with 3-butyn-1-ol: A new synthesis of tetrahydrofurans

A simple and efficient method has been developed for the synthesis of tetrahydrofurans. This method is based on the Cu(I)-catalyzed cascade coupling/cyclization reaction of N-tosylhydrazones with 3-butyn-1-ol, and involves a Cu(I) carbene migratory insertion as one of its key steps.