14911-58-1Relevant academic research and scientific papers
Relative reactivities of anionic transition-metal hydrides. Reduction of alkyl halides
Kao,Darensbourg, Marcetta Y.
, p. 646 - 647 (1984)
A comparison of the second-order rate constants for halide displacement from n-BuBr by H- derived from anionic transition-metal hydrides established the following order of reactivity: cis-HW(CO)4P(OMe)3- > cis-HCr(CO)4P(OMe)3- > HW(CO)5- > CpV(CO)3H- > HCr(CO)5- > HRu(CO)4- ? HFe(CO)4- (no reaction). The lack of dependence of reactivity on degree of branching of the alkyl halide for HM(CO)5- (M = Cr, W) and a dramatic diminishing of reactivity for HM(CO)4P(OMe)3-, 1° ? 2° > 3°, resulted in a different order of reactivity on the basis of t-BuBr: HCr(CO)5- > HW(CO)5- > cis-HCr-(CO)4P(OMe)3- > CpV(CO)3H- > cis-HW(CO)4P(OMe)3- ? HFe(CO)4- (no reaction). Mechanistic probes were applied to reactions of HW(CO)5- and cis-HW(CO)4P-(OMe)3-, and preliminary results suggest the former to involve some radical character (single electron transfer) and the latter to react with considerable ionic character (H- transfer).
