The Imino-pinacol Coupling Reaction

interest in imino-pinacol coupling arises from the access it offers to 1,2-diamines, a highly valuable class of compounds that have found constant applications in medicinal chemistry and asymmetric catalysis. The present paper intends to cover, from the 60's to present, the different chemical approaches applied to the imino-pinacol coupling, setting each procedure in an historical perspective and delineating general reactivity trends. This review shows that, even though the last 40 years has witnessed an impressive evolution, there is still room for improvement both in terms of flexibility and stereoselectivity.