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.