Carbene transfer reactivity from a nickelacyclobutane.

A formal carbene-transfer reaction from an isolated nickelacyclobutane to an isocyanide to form a ketenimine is reported. DFT calculations support a stepwise 1,1-insertion/fragmentation pathway without a carbene intermediate. This unusual reactivity suggests a potential new role as "carbene reservoir" for nickelacyclobutanes, which are typically seen as intermediates in catalytic cyclopropanation. [ABSTRACT FROM AUTHOR]