Hydroperoxide-Initiated Intramolecular Insertions of NO into Metal-Carbon Bonds.

The chem. transformations of metal-bound NO groups (i.e., nitrosyl ligands) have attracted considerable attention because of both their fundamental significance and their possible biol. and environmental relevance. We now report our novel discovery that an oxygen-atom transfer reagent can initiate the subsequent intramol. insertion of bound NO into an adjacent metal-ligand bond. Specifically, we have demonstrated that treatment of the dialkyl compds. Cp*Mo(NO)(CH2CMe3)2 (1) and Cp*W(NO)(CH2SiMe3)2 (3) (Cp* = η5-C5Me5) with cumene hydroperoxide induces the insertion of NO into one of their metal-carbon bonds and results in the clean formation of the η2-nitrosoalkane oxo complexes Cp*Mo(O)(η2-ONCH2CMe3)(CH2CMe3) (2) and Cp*W(O)(η2-ONCH2SiMe3)(CH2SiMe3) (4). Further treatment of complexes 2 and 4 with excess O2 results in liberation of the nitroalkanes O2NCH2EMe3 (E = C, Si) from the metals’ coordination spheres and formation of the dioxo alkyl complexes Cp*Mo(O)2(CH2CMe3) (5) and Cp*W(O)2(CH2SiMe3) (6). The crystal structures of 2 and 4 were detd. [on SciFinder(R)]