In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a C sp 3 -C sp 3 Stille Coupling.

Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional C sp 2 -C sp 2 cross-coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the cross coupling of allylstannanes and activated alkylbromides to form C sp 3 -C sp 3 bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solid support, which allowed for convenient catalyst recovery and reuse. The present study is a rare case where a gold metal catalyst is superior to Pd catalysts in a cross-coupling reaction of an organic halide and an organometallic reagent.