The role of α-hydrogen elimination reactions in the formation of η3-cyclopropenyl-and η4-cyclopentadiene-molybdenum complexes

Abstract

Reaction of the Grignard reagents RMgX (R = Me or CHCH₂) with [Mo(η²-PhC₂Ph){P(OMe)₃}₂(η-C₅H₅)][BF₄] leads to selective attack on molybdenum and formation of the complexes [MoR(η²-PhC₂Ph){P(OMe)₃}(η-C₅H₅)] which undergo thermally promoted α-hydrogen elimination reactions to give η³-cyclopropenyl and η⁴-cyclopentadiene complexes, the latter being identified by X-ray crystallography.