In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a C−C Stille Coupling

Abstract

Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional C <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>sp</mml:mi> <mml:msup><mml:mrow></mml:mrow> <mml:mn>2</mml:mn></mml:msup> </mml:mrow> </mml:msub> </mml:math> -C <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>sp</mml:mi> <mml:msup><mml:mrow></mml:mrow> <mml:mn>2</mml:mn></mml:msup> </mml:mrow> </mml:msub> </mml:math> 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>sp</mml:mi> <mml:msup><mml:mrow></mml:mrow> <mml:mn>3</mml:mn></mml:msup> </mml:mrow> </mml:msub> </mml:math> -C <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>sp</mml:mi> <mml:msup><mml:mrow></mml:mrow> <mml:mn>3</mml:mn></mml:msup> </mml:mrow> </mml:msub> </mml:math> 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.