Different Modes of Reactivity of Cp*W(NO)(alkyl)(η3-allyl) Complexes with Cyclic Amines: The Influence of the Allyl Ligands

Abstract

Metathesis reactions between Cp*W(NO)(CH2EMe3)Cl (E = C or Si) and a variety of bis(allyl)magnesium reagents lead to the formation of 18e Cp*W(NO)(alkyl)(η3-allyl) complexes. The compounds Cp*W(NO)(CH2CMe3)(η3-CH2CHCMe2) (1), Cp*W(NO)(CH2CMe3)(η3-CH2CMeCH2) (2), Cp*W(NO)(CH2CMe3)(η3-CH2CHCHMe) (3), Cp*W(NO)(CH2CMe3)(η3-CH2CHCHPh) (4), Cp*W(NO)(CH2SiMe3)(η3-CH2CHCHMe) (5), and Cp*W(NO)(CH2CMe3)(η3-CH2CHCH2) (6) have thus been synthesized in moderate yields. The solid-state molecular structures of 3, 4, 5, and 6 feature σ−π distorted allyl ligands in the endo conformation. Complex 1 effects the concurrent N−H and α-C−H activations of pyrrolidine and piperidine under ambient conditions and forms the alkyl amido complexes Cp*W(NO)(CH2CMe3)(NC4H7-2-CMe2CH═CH2) (7) and Cp*W(NO)(CH2CMe3)(NC5H9-2-CMe2CH═CH2) (8), respectively. Complexes 2−5 react with pyrrolidine in a similar manner, but the reaction of 3 to produce Cp*W(NO)(CH2CMe3)(NC4H7-2-CH2CMe═CH2) (10) is not as clean since 3 is thermally unstable at 20 °C....