114180-68-6Relevant articles and documents
Subtle Effects in the Asymmetric Epoxidation: Dependence of Kinetic Resolution Efficiency on the Monodentate Alkoxide Ligands of the Bystander Titanium Center
McKee, Blaine H.,Kalantar, Thomas H.,Sharpless, K. Barry
, p. 6966 - 6968 (1991)
Complexes of diisopropyl tartrate and Ti(OtBu)4 were found to catalyze the kinetic resolution of racemic, secondary allylic alcohols with surprisingly low efficiency relative to those generated from Ti(OiPr)4.This effect is documente
Mechanism of asymmetric epoxidation. 1. Kinetics
Woodard, Scott S.,Finn,Sharpless, K. Barry
, p. 106 - 113 (2007/10/02)
The rate of titanium-tartrate-catalyzed asymmetric epoxidation of allylic alcohols is shown to be first order in substrate and oxidant, and inverse second order in inhibitor alcohol, under pseudo-first-order conditions in catalyst. The rate is slowed by substitution of electron-withdrawing substituents on the olefin and varies slightly with solvent, CH2Cl2 being the solvent of choice. Asymmetric induction suffers when the size of the alkyl hydroperoxide is reduced. Kinetic resolution of secondary allylic alcohols is shown to be sensitive to the size of the tartrate ester group and insensitive to the steric nature of inhibitor alcohol. Most importantly, the species containing equimolar amounts of Ti and tartrate is shown to be the most active catalyst in the reaction mixture, mediating reaction at much faster rates than titanium tetraalkoxide alone.
