Molybdenum promoted alkyne dimerisation leading to novel metallacycles: the crystal and molecular structures of prone-[Mo{η4-C(CF3)C(CF3)C(Me)C(CO2Me)(SC6F5)}(CF3CCCF3)(η5-C5H5)] and supine-[Mo{η4-C(CF3)(SC6F5)C(CF3)C(Ph)C(Ph)}-(CF3CCCF3)(η5-C5H5)]

Abstract

Reactions of alkynes with [MoSC₆F₅(CF₃CCCF₃)₂(η⁵-C₅H₅)]1 gives the novel proneη⁴-butadienyl complex [Mo{η⁴-C(CF₃)C(CF₃)C(R′)C(R)(SC₆F₅)}(CF₃CCCF₃)(η⁵-C₅H₅)], which undergoes isomerisation via an η²-vinyl intermediate to the supine isomer followed by a novel 1,4-thiolate migration to give supine-[Mo{η⁴-C(CF₃)(SC₆F₅)C(CF₃)C(R)C(R′)}(CF₃CCF₃)(η⁵-C₅H₅)].