IMINO ENE REACTIONS IN ORGANIC-SYNTHESIS

During the last decade the ene reaction has achieved wide recognition as a powerful carbon-carbon bond forming method in synthetic organic c hemistry. The imino ene reaction, however, is still a relatively rare transformation despite its potential for preparation of nitrogen heter ocycles and in alkaloid total synthesis. This review describes mechani stic aspects of the imino ene reaction and illustrates a number of syn thetic applications of this versatile process. The details of inter- a nd intramolecular imino ene reactions involving N-alkyl, N-acyl, and N -sulfonyl imines or iminium ions are presented with particular emphasi s on the regio- and stereochemical issues accompanying these processes . A discussion of retro imino ene reactions is also included.