Reactions of acyl- and alkyl-(tricarbonyl)(η5-cyclopentadienyl)-molybdenum and -tungsten complexes with but-2-yne; molecular structures of [Mo(CO)(ButNC)(η3-{O·C(O)·CMe·CMe·CMe})(η5-C5H5)] and [Mo·C(O)·C(Me){C(Me)}2C(Me)·C(CF3)·O(CO)(η5-C5H5)]

Abstract

Reaction of [MR(CO)₃(η⁵-C₅H₅)](M = Mo, W; R = Me, CH₂Ph, COCF₃) with but-2-yne affords either the vinylketone complexes [[graphic omitted])R(CO)₂(η⁵-C₅H₅)], which on treatment with ligands L form lactone complexes [M(CO)L(η³-{[graphic omitted]Me})(η⁵C₅H₅)], or the eight-membered ring complex [[graphic omitted](CO)(η⁵-C₅H₅)]; the identity of the products is established by X-ray crystallography.