Site-Selective Silylation of Aliphatic C-H Bonds Mediated by [1,5]-Hydrogen Transfer: Synthesis of α-Sila Benzamides.

The first example of site-selective silylation of C(sp3 )-H bonds mediated by a [1,5]-hydrogen transfer is reported. This reaction occurs selectively at the α-position of benzamides with a combination of tert-butylmagnesium chloride and a catalytic amount of 4,4'-di-tert-butylbipyridine (dtbpy) ligand and provides a facile route for the creation of biologically interesting α-sila benzamides. Late-stage functionalization of the incorporated silyl moieties facilitates the synthesis of N-formyl, cis-enamine, β-hydroxyl, amino, and pyrrole-containing derivatives.