A General Copper Catalytic System for Cross-Coupling of Aryl Iodides with Chlorosilanes under Reductive Conditions

Directly forged linkages between commercially available electrophiles are powerful synthetic tools for chemical bond construction. This strategy could eliminate the pre-synthesis of reactive organometallic reagents in couplings with electrophiles, thus providing efficient, easily-handled and step-economical routes in organic synthesis. Reported approaches are mainly utilized in carbon-carbon bond formations, whereas carbon-silicon bond construction employing halosilanes with carbon electrophiles is still underexplored. Copper-catalysis has made significant achievements in the coupling reactions of carbon halides in the past decades, yet silyl electrophiles are seldom involved in these systems. Herein, we establish a practical, efficient, and economical copper system catalyzing the construction of Csp2-Si bonds by directly using aryl/vinyl iodides with various chlorosilanes under ligand-free and reductive conditions, thus providing a general platform for organosilane synthesis with broad scope, high functionality tolerance, scalability and operational simplicity. An unprecedented mechanistic motif was obtained to suggest that the copper catalyst was likely to lower the energy barrier in the reaction of the in situ generated arylzinc with halosilanes, rather than proceed via the traditional metal-aryl species.