A3-Coupling Reaction as a Strategy Towards the Synthesis of Alkaloids

A number of aldehydes, alkynols and benzylamines were submitted to A(3)-coupling reaction, under CuCl catalysis, giving strategically functionalized hydroxy-propargylamines. The procedure allows the use of alkyl as well as aryl aldehydes. Representative substrates were converted into five- and six-membered cyclic alkaloids by sequential one-pot N-debenzylation/triple bond reduction promoted by Pd, followed by a Mitsunobu-type cyclization.