Reductive Cross-Coupling of Alcohol Derivatives with Chlorosilanes via Pyridines-Promoted Si─Cl Activation

The development of efficient approaches mediated by silyl radicals for constructing C─Si bonds is of great interest and importance, yet methods to generate these intermediates from readily available chlorosilanes remain scarce. Herein, we report a new strategy for silyl radical generation via pyridines-promoted reductive Si─Cl activation of chlorosilanes and demonstrate its application in the reductive cross-coupling with a wide array of benzyl, allyl, and propargyl alcohol derivatives. This protocol offers an efficient and step-economical route for the synthesis of diverse benzyl-, allyl-, and allenylsilanes, featuring broad substrate scope and easy scalability. Mechanistic investigations suggest that the coupling reaction was initiated by the reductive Si─Cl activation of chlorosilanes with magnesium promoted by pyridine derivatives, which generates silyl radicals. These silyl radicals subsequently mediate the deoxygenation of alcohol derivatives to form carbon radicals, culminating in C─Si radical-radical cross-coupling.