Synthesis of highly substituted 2,3-dihydro-1H-pyrrole derivatives via a tandem regioselective addition of nitrones to 1,3-enynes with subsequent rearrangement.

A novel method for the synthesis of 1,3-enynes is described through oxidative cyclization of the semicarbazones of Michael adducts having potential nitrile functionality. Reaction of these 1,3-enynes with diaryl nitrones has yielded a diastereomeric mixture of highly substituted 2,3-dihydro-1H-pyrrole derivatives via a tandem regioselective addition with subsequent rearrangement.