Reactions of a Tungsten–Germylyne Complex with α,β-Unsaturated Ketones: Complete Cleavage of the W≡Ge Bond and Formation of Two Types of η3-Germoxyallyl Tungsten Complexes

Abstract

Germylyne complex Cp*(CO)2W≡Ge{C(SiMe3)3} (1) reacted with two molecules of RC(O)CH═CH2 (R = Me, Et) to give η(3)-allyl complexes, in which an oxagermacyclopentene framework was bound to an η(3)-allyl ligand through an oxygen atom. In the reaction with α-Me-substituted MeC(O)C(Me)═CH2, 1 reacted with only one molecule of the substrate to give another type of η(3)-allyl complex, in which a five-membered oxagermacyclopentenyl ring was coordinated to the W center in an η(3) fashion. Both reactions resulted in unprecedented complete cleavage of a W≡Ge triple bond.