Stereochemistry of chiral, nonracemic lithium salts of acyclic .alpha.-sulfonyl carbanions: the asymmetric induction exerted by the lithium-coordinated sulfonyl group
作者:Hans Joachim Gais、Gunther Hellmann
DOI:10.1021/ja00037a082
日期:1992.5
Enantioselective Synthesis, Configurational Stability, and Reactivity of Lithium α-tert-Butylsulfonyl Carbanion Salts
first-order kinetics and seems to be mainly an enthalpic process with a small negative activation entropy, as revealed by polarimetric measurements at low temperatures. This is in accordance with Cα–S bondrotation as the rate-determining step. The salts [R1C(R2)SO2tBu]Li have half-lives of racemization in the order of several hours at –105 °C. The deuteriation of the salts at –105 °C with CF3CO2D