Reaction of Tantalum-Alkyne Complexes with Isocyanates Leading to (E)-α,β-Unsaturated Amides. Stereoselective Functionalization of Carbon-Carbon Triple Bonds

Article abstract of DOI:10.1246/cl.1991.1479

Treatment of alkynes with low-valent tantalum derived from TaCl5 and zinc produces tantalum-alkyne complexes (not isolated), which react with phenylisocyanate (or butylisocyanate) to give (E)-α,β-unsaturated amides stereoselectively.