Reaction of α,β-alkynylketones with β-amino alcohols: pseudoephedrine- assisted cleavage of triple bond via formal internal redox process

Reaction of 3-aryl-1-(3,4,5-trimethoxyphenyl)prop-2-yn-1-ones with (+)-pseudoephedrine leads to products of alkyne moiety cleavage, namely, 1-(3,4,5-trimethoxyphenyl)ethanone and N -(1-hydroxy-1-phenylprop-2-yl)- N -methylbenzamides. In the course of the process one of alkyne carbons undergoes a formal reduction to a Me group, whereas the other one is oxidized to a C(O)NRR ’ moiety.