Unprecedented Reactivity Initiated by Insertion of 2,6-Xylylisonitrile into the W-Alkyl Linkages of Cp*W(NO)(n-alkyl)(eta(3)-CH2CHCHMe) Complexes

Treatment of the compounds Cp*W(NO)(R)(eta(3)- CH2CHCHMe) (R = n-C5H11, n-C7H15, n-C8H17) with 2,6-xylylisonitrile first produces the expected complexes bearing eta(2)-iminoacyl ligands arising from migratory insertion of the isonitrile into the tungsten-alkyl linkages, processes that result in the allyl ligands undergoing concomitant eta(3) -> eta(1) haptotropic shifts. These eta(1)-allyl complexes then undergo subsequent intramolecular nucleophilic attacks by their allyl groups on the nitrogen atoms of the eta(2)-iminoacyl ligands to form novel metallacyclic compounds that contain alpha-aminocarbene ligands.