Sequential decarboxylative azomethine ylide cycloaddition-palladium catalysed hydrostannylation-cyclisation-anion capture processes

A novel tactical combination of the iminium ion induced decarboxylative gen eration of azomethine ylides, from secondary acyclic and cyclic a-an-lino a cids, and their 1,3-dipolar cycloaddition, with regioselective palladium ca talysed hydrostannylation of terminal alkynes, and subsequent cyclisation-a nion capture of the organostannane is described. A major increase in molecu lar complexity results with the formation of 5 bonds, 5 stereocentres, 2 ri ngs and I tetra-substituted carbon centre. (C) 2001 Elsevier Science Ltd. A ll rights reserved.