Optically active acylsilanes. Synthesis of selected 2,3-O-isopropylidene-1-(trialkyl/arylsilyl)glyceraldehyde derivatives
作者:Piotr Raubo、Jerzy Wicha
DOI:10.1016/0957-4166(95)00041-m
日期:1995.2
Syntheses of 1-trimethylsilyl-, 1-tert-butyldimethylsilyl, 1-dimethylphenylsilyl- and 1-triphenylsilyl-2,3-O-isopropylideneglyceraldehyde derivatives, 6a, 6b, 6c, and 6d, respectively, is described.
Mechanism of asymmetric epoxidation. 1. Kinetics
作者:Scott S. Woodard、M. G. Finn、K. Barry Sharpless
DOI:10.1021/ja00001a018
日期:1991.1
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 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 that titanium tetraalkoxide alone.
Raubo, P.; Wicha, J., Polish Journal of Chemistry, 1995, vol. 69, # 1, p. 78 - 84
作者:Raubo, P.、Wicha, J.
DOI:——
日期:——
Stereocontrolled synthesis of α-trialkylsilyl-β, γ-unsaturated aldehydes via palladium (0) catalysis. Synthetic usefulness
作者:Franck Le Bideau、Fabienne Gilloir、Ylva Nilsson、Corinne Aubert、Max Malacria
DOI:10.1016/0040-4020(96)00264-5
日期:1996.5
The reaction of silicon substituted vinyloxiranes in the presence of catalytic amount of palladium (0) catalyst affords the title compounds. This new reaction proceeds smoothly, under very mild conditions and with complete chirality transfer. One-pot addition of selected organometallic nucleophiles to these aldehydes at very low temperature led to a highly selective preparation of the corresponding