Recyclable Copper(I)-Catalyzed Cross-Coupling of Trialkylsilylethynes and N-Tosylhydrazones Leading to the Formation of C(sp)–C(sp³) Bonds

A highly efficient heterogeneous copper(I)-catalyzed cross-coupling of trialkylsilylethynes with N-tosylhydrazones has been achieved in dioxane at 90-110 degrees C via the Cu carbene migratory insertion with an SBA-15-immobilized L-proline-Cu(I) complex [SBA-15-L-Proline-CuI] as the catalyst and (LiOBu)-Bu-t as the base, leading to the formation of C(sp)-C(sp(3)) bonds. The reaction generates a wide variety of alkyltrialkylsilylalkynes in moderate to high yields. This new heterogenized copper(I) complex exhibits a comparable catalytic efficiency to homogeneous CuI and can be easily recovered through a simple centrifugation process and is recyclable up to 12 times without a remarkable loss of activity.