InBr3–Et3N promoted alkynylation of aldehydes and N,O-acetals under mild conditions: facile and simple preparation of propargylic alcohols and amines

The use of a novel InBr3–Et3N reagent system to promote addition reactions of 1-alkynes not only with a variety of aromatic or bulky aliphatic aldehydes but also with N,O-acetals is described. The corresponding propargylic alcohols or amines are produced in good to excellent yields.