Copper-catalyzed desymmetric silylative-cyclization of 1,6-diynes for synthesis of spirocyclic compounds

Spiro rings such as spirooxindoles and spiroindanones are core skeletons in many pharmaceutically active molecules and natural products. Herein, we developed a copper-catalyzed cascade silylation-cyclization reaction of 1,6-diynes which enabled the rapid construction of silyl-functionalized spirocyclic compounds. A variety of racemic and optically pure spirocyclic oxindole, indanone, quinolinone, and tetralone derivatives were obtained in high yields with excellent enantioselectivities and high stereoselectivities. The silylative-cyclization desymmetrization of 1,6-diynes has been realized. This reaction enabled the construction of silyl-functionalized spirocyclic oxindoles, indanone, quinolinone, and tetralone derivatives from readily available 1,6-diynes.