Development of a one-pot asymmetric azaelectrocyclization protocol: synthesis of chiral 2,4-disubstituted 1,2,5,6-tetrahydropyridines.

[reaction: see text] A one-pot procedure for tetracyclic chiral aminoacetals, the useful precursors for substituted piperidine synthesis, has been established via Stille-Migita coupling, 6pi-azaelectrocyclization, and aminoacetal formation from readily prepared vinylstannanes, vinyliodides, and cis-aminoindanol derivatives. Based on the method, chiral 2,4-disubstituted 1,2,5,6-tetrahydropyridines, bearing a variety of aromatic substituents at the C-2 position, have been prepared.