Metalation-induced denitrogenative reductive coupling of isocyanides on a silylene-bridged nickel cluster.

The denitrogenative reductive coupling of two molecules of CN t Bu to afford a disilylketenimine with an aza-disilacyclobutane skeleton was achieved on a multinuclear silylene-bridged Ni cluster framework in the absence of any strong reducing reagents. During this reaction, sequential cleavage of a C[triple bond, length as m-dash]N bond and formation of a C[triple bond, length as m-dash]C bond involving two molecules of CN t Bu were achieved on a nickel cluster surrounded by four silylene moieties. First, the cleavage of the C[triple bond, length as m-dash]N bond of one molecule of CN t Bu provided a silylene-supported carbide and an N t Bu moiety on the dinuclear nickel skeleton. Further metalation induced coupling between the carbide moiety and an additional molecule of CN t Bu on the pentanuclear nickel-cluster framework to form a moiety via formation of a C[triple bond, length as m-dash]C bond. Thermolysis of this pentanuclear cluster produced a disilylketenimine with an aza-disilacyclobutane skeleton in 58% yield.