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

A novel tactical combination of the iminium ion induced decarboxylative generation of azomethine ylides, from secondary acyclic and cyclic α-amino acids, and their 1,3-dipolar cycloaddition, with regioselective palladium catalysed hydrostannylation of terminal alkynes, and subsequent cyclisation-anion capture of the organostannane is described. A major increase in molecular complexity results with the formation of 5 bonds, 5 stereocentres, 2 rings and 1 tetra-substituted carbon centre.