Unprecedented Reactivity Initiated by Insertion of 2,6-Xylylisonitrile into the W−Alkyl Linkages of Cp*W(NO)(<i>n</i>-alkyl)(η³-CH₂CHCHMe) Complexes

Treatment of the compounds Cp*W(NO)(R)(η3-CH2CHCHMe) (R = n-C5H11, n-C7H15, n-C8H17) with 2,6-xylylisonitrile first produces the expected complexes bearing η2-iminoacyl ligands arising from migratory insertion of the isonitrile into the tungsten−alkyl linkages, processes that result in the allyl ligands undergoing concomitant η3 → η1 haptotropic shifts. These η1-allyl complexes then undergo subsequent intramolecular nucleophilic attacks by their allyl groups on the nitrogen atoms of the η2-iminoacyl ligands to form novel metallacyclic compounds that contain α-aminocarbene ligands.