Publication number: 20110166360
Abstract: A process for preparing the S or R enantiomer of a compound of formula A, the process comprising subjecting a compound of formula B to asymmetric hydrogenation in the presence of a chiral transition metal catalyst and a source of hydrogen, wherein: X is CH2, oxygen or sulphur; R1, R2 and R3 are the same or different and signify hydrogen, halogen, alkyl, alkyloxy, hydroxy, nitro, alkylcarbonylamino, alkylamino or dialkylamino group; and R4 is alkyl or aryl, the transition metal catalyst comprising a chiral ligand having the formula wherein each R and R? independently represents alkyl, aryl, aralkyl, alkenyl, alkynyl, alkoxy, aryloxy, alkylthio, arylthio, unsubstituted or substituted cyclic moiety selected from a group consisting of monocyclic or polycyclic saturated or partially saturated carbocyclic or heterocyclic, aromatic or heteroaromatic rings said rings comprising from 4 to 8 atoms and comprising from 0 to 3 heteroatoms, wherein: the term alkyl means hydrocarbon chains, straight or branched, con
Type:
Application
Filed:
March 13, 2009
Publication date:
July 7, 2011
Applicant:
BIAL - PORTELA & CA, S.A.
Inventors:
Alexander Beliaev, David Alexander Learmonth, Juan José Almena Perea, Gerhard Geib, Patrick Hitzel, Renat Kadyrov, David Voigtlaender
Publication number: 20110112303
Abstract: A process for preparing the S or R enantiomer of a compound of formula A, the process comprising subjecting a compound of formula B to asymmetric hydrogenation in the presence of a chiral transition metal catalyst and a source of hydrogen, wherein X is CH2, oxygen, or sulphur; R1, R2 and R3 are the same or different and signify hydrogens, halogens, alkyl, alkyloxy, hydroxy, nitro, alkylcarbonylamino, alkylamino, or dialkylamino group; and R4 is alkyl or aryl, wherein the transition metal catalyst comprises a chiral ligand having the formula wherein p is from 1 to 6, and Ar means aryl group; wherein the term alkyl means hydrocarbon chains, straight or branched, containing from one to six carbon atoms, optionally substituted by aryl, alkoxy, halogen, alkoxycarbonyl or hydroxycarbonyl groups; the term aryl means an aromatic or heteroaromatic group, optionally substituted by alkyloxy, halogen, or nitro group; and the term halogen means fluorine, chlorine, bromine, or iodine.
Type:
Application
Filed:
March 17, 2009
Publication date:
May 12, 2011
Applicant:
BIAL - PORTELA & CA, S.A.
Inventors:
David Alexander Learmonth, Alexander Beliaev, Wenge Li