.sigma.-Bond metathesis for carbon-hydrogen bonds of hydrocarbons and Sc-R (R = H, alkyl, aryl) bonds of permethylscandocene derivatives. Evidence for noninvolvement of the .pi. system in electrophilic activation of aromatic and vinylic C-H bonds
作者:Mark E. Thompson、Steven M. Baxter、A. Ray Bulls、Barbara J. Burger、Michael C. Nolan、Bernard D. Santarsiero、William P. Schaefer、John E. Bercaw
DOI:10.1021/ja00235a031
日期:1987.1
H/sub 2/ and hydrocarbons. Experiments designed to probe the mechanism of these processes have been carried out, and the possibility of involvement of the ..pi.. system in electrophilic activation of aromatic and vinylic C-H bonds has been examined. A picture of the transition state for such sigma-bond metathesis reactions is developed, which accounts for the relative reactivities of sp-, sp/sup 2/-