Study on reactivity of five-coordinate bicycloazastannoxides. IV. Michael addition with acrylonitrile

Michael addition of alpha-carbanions formed from the alpha-amino acids in f ive-coordinate bi-cycloazastannoxides (1-6) with acrylonitrile was investig ated. Four novel organotin (IV) complexes (7-10) and one new five-membered alpha-amino acid (11) were synthesized, and their structures were character ized by IR, H-1 NMR spectroscopy MS, and elemental analyses. It has been fo und that the Michael addition lakes place by two paths, 1,2-addition (path A) and cycloaddition (path B), and the alpha- and gamma-carbanion intermedi ates are involved. (C) 1999 John Wiley & Sons, Inc.