The reaction mechanism of the Birchreduction was investigated with a view of determining how the regioselectivity is controlled. Regioselectivity is determined in the first step of radical anion protonation and in the second step of cyclohexadienyl carbanion protonation. It was ascertained that the rate-determining step of the Birchreduction of anisole was radical anion protonation, consistent with
Trimethylstannyl-2,4-cycloheptadiene: A fluxional molecule
作者:M. David Curtis、Robert Fink
DOI:10.1016/s0022-328x(00)83332-x
日期:1972.5
Trimethylstannyl-2,4-cycloheptadiene (II) was synthesized and shown to be fluxional on the NMR time scale. The activation energy for the [1,5] trimethyltin migration is estimated to be ca. 18 kcal/mole. This value is compared with estimated activation energies of 14 kcal/mole for trimethylstannylindene (IV) and 6 kcal/mole for cyclopentadienyltrimethylstannane (I, ESn). 1,1-Dimethyl-4-trimethylstannyl-2