Synthesis and reactivity of η3-butadienyl molybdenum complexes formed by deprotonation or desilylation of 1,3-diene cations; structure of [Mo(CO)2(η3-CH2CHCCH2)(η-C5Me5)]
Abstract
Reaction of [Mo(CO)2(η4-CH2CH–CHCH2)(η-C5Me5)][BF4](4) with Li[N(SiMe3)2] in tetrahydrofuran (THF) at –78 °C results in an unusual deprotonation reaction affording, in low yield, the novel η3-butadienyl complex [Mo(CO)2(η3-CH2CHCCH2)(η-C5Me5)](5), which has been characterised by X-ray crystallography; the fluoride anion-induced desilylation of [Mo(CO)2(η4-CH2CH–C–{SiEt3}CH2)(η-C5Me5)][BF4](6), using Bu4NF affords (5) in quantitative yield, facilitating a rational strategy for the synthesis of these complexes, which on protonation access cationic species containing η3-vinylcarbene ligands.