Acid instead of base: Kineticresolution of secondary alcohols is realized using chiral Brønsted acid catalyzed acylation instead of the conventional basic conditions. A broad range of functional groups are tolerated, such as aldehydes, carboxylic acids, and enoates. The selectivity factor (s) reaches up to 215 at ambient temperature.
Nonenzymatic kinetic resolution of racemicsecondaryalcohols is an efficient synthetic method to obtain optically active compounds in organic chemistry. Catalytic asymmetric acylation of racemicsecondaryalcohols has been successfully performed with achiral benzoyl chloride in the presence of only 0.3 mol% of chiral diamine (3) derived from (S)-proline, combined with 0.5 equivalent of triethylamine
steps, C–C bondcleavage and C–C bond formation, to achieve multiplicative enhancement of stereoinduction, which leads to high levels of stereoselectivity. Ligand-to-metal charge transfer excitation of a titanium catalyst coordinated by a chiral phosphoric acid or bisoxazoline efficiently enriches racemic alcohols that feature adjacent and fully substituted stereogenic centers to enantiomeric ratios up
Structural effects in solvolytic reactions. VI. Rates and products in the acetolysis of substituted trans-2-phenylcyclopentyl tosylates and optically active derivatives. Nature of the aryl-assisted and the aryl-unassisted reaction pathways
作者:C. J. Kim、Herbert C. Brown
DOI:10.1021/ja00769a044
日期:1972.7
Quantitative Analyses of the Four Isomers of 3,4-Diphenylcyclopentene by Chiral Gas Chromatography
作者:Lisa A. Asuncion、John E. Baldwin
DOI:10.1021/jo00123a010
日期:1995.9
The four isomers of 3,4-diphenylcyclopentene are well resolved by chiral gas chromatography on a Cyclodex B column, eluting in the ordered sequence (3S,4R), (3R,4S), (3S,4S), and(3R,4R). Absolute stereochemical assignments were made through chemical correlations relating the 3,4-diphenylcyclopentenes with a known reference compound, (1S,2S)-(+)-cis-2-phenylcyclopentanol.