New pentacoordinated Schiff-base diorganotin(IV) complexes derived from nonpolar side chain α-amino acids

In this work we report the synthesis and spectroscopic characterization of twenty new pentacoordinated diorganotin(IV) compounds. These compounds have been prepared in good yields by multicomponent reactions (MCRs) of alpha-amino acids (isoleucine, leucine, methionine, phenylalanine and aminophenylacetic acid), 2,4-dihydroxybenzaldehyde, 2-hydroxy-4-methoxybenzaldehyde and either di-n-butyltin(IV) oxide or diphenyltin(IV) oxide. All compounds were characterized by IR spectroscopy, H-1, Sn-119 and C-13 NMR spectroscopy and mass spectrometry. Each compound has a coordinative N -> Sn bond and shows the expected Sn-119 NMR chemical shift indicative of a pentacoordinated or hexacoordinated tin atom in CDCl3 and DMSO-d(6), respectively. These compounds were also tested in tumoral cell lines, HeLa, HCT-15 and MCF-7, in order to evaluate the antiproliferative activity and to obtain the medial inhibitory concentrations (IC50) values. (C) 2010 Elsevier B.V. All rights reserved.