gem-Heterosubstituted (stannyl)methylsilanes as synthetic equivalents of functionalized alfa-stannyl(methyl) anions

alfa-Heterosubstituted silyl derivatives, such as phenylthio-, phenylseleno- and benzotriazolyl-stannyl silanes, react with aldehydes under tetra-n-butylammonium fluoride (TBAF) catalysis, leading to alfa-substituted-beta- hydroxy stannanes, able to behave as precursors of Z- and E-olefins, generated by deoxystannylation. This reactivity shows the capability of such heterosubstituted silanes to act as masked carbanions through a mild functionalization of the carbon-silicon bond