Process for preparation of optically active .alpha.-bromo and .alpha.-chlorocarboxylic compounds
US5852212A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1996 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Jun 12, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/55
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Optically active .alpha.-bromo- or .alpha.-chlorocarboxylic compounds of the formula ##STR1## wherein X is bromine or chlorine; PA1 M is hydrogen, NR.sub.4.sup.+1 or a cation of an alkali or alkaline earth metal; PA1 R.sup.1 is hydrogen or lower alkyl; PA1 n is 0 or 1; PA1 R is hydrogen, C.sub.1 -C.sub.20 alkyl, or C.sub.1 -C.sub.20 alkyl substituted in the terminal position with --NR.sup.2.sub.2, --COOR.sup.2, --OR.sup.3, a free or protected --CHO group or a ring A; PA1 R.sup.2 is hydrogen or a lower alkyl; PA1 R.sup.3 is hydrogen or a protecting group; PA1 ring A is an unsubstituted or substituted ring; and PA1 * is a center of chirality, are prepared by enantioselectively hydrogenating, in the presence of a ruthenium complex of an optically active diphosphine ligand, a (Z)-.alpha.,.beta.-unsaturated compound of the general formula ##STR2## wherein R, n, X and M are as defined above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.