摘要:
Process for stereoselective hydrogenation by reacting racemic aldehydes or ketones having a stereogenic carbon atom in the position relative to the C(O) group and containing the structural element —(O)C—C—CH— by means of hydrogen in the presence of a base and a ruthenium complex containing a bidentate ligand having coordinating P and N atoms, a monophosphine ligand and anionic and/or uncharged ligands as homogeneous catalyst, with the charge being balanced by one or two monovalent acid anions or a divalent acid anion when uncharged ligands are present.
摘要:
Abstract Compounds of the formula (I) in the form of racemates, enantiomerically pure diastereomers or a mixture of diastereomers, where the radicals R1 are identical or different and are each C1-C4-alkyl; m is 0 or an integer from 1 to 4; n is 0 or an integer from 1 to 3; p is 0 or an integer from 1 to 5; R2 is an aromatic hydrocarbon radical or a C-bonded heterohydrocarbon radical and R3 is an aliphatic or C-bonded heteroaliphatic hydrocarbon radical; R2 and R3 are identical or different and are each an aliphatic or C-bonded heteroaliphatic hydrocarbon radical; R4 is an unsubstituted or C1-C6-alkyl-, C1-C6-alkoxy- or halogen-substituted hydrocarbon radical; and A is a secondary amino group, are ligands for metal complexes which are suitable as catalysts for homogeneous enantioselective hydrogenation.
摘要:
The invention relates to a novel process of diastereoselective hydrogenation of 1,3-hydroxyketones of formula (I) wherein R, R′ and R″ are as defined in claim 1 which is carried out in a solvent in the presence of a magnesium salt, a heterogeneous platinum catalyst and optionally an oxidant.
摘要:
The invention relates, in general, to an improved process for converting compounds of Formula II (below) to compounds of Formula III (below), which are key intermediates for the synthesis of ezetimibe, or to ezetimibe itself, wherein in Formulas II and III, R represents hydrogen, alkyl, or a hydroxyl protecting group (e.g., benzyl group, a substituted benzyl group, or a silyl group). The invention further includes the use of the described process and the use of compounds of Formula III made by the described process for the preparation of ezetimibe.
摘要:
Abstract Compounds of the formula (I) in the form of racemates, enantiomerically pure diastereomers or a mixture of diastereomers, where the radicals R1 are identical or different and are each C1-C4-alkyl; m is 0 or an integer from 1 to 4; n is 0 or an integer from 1 to 3; p is 0 or an integer from 1 to 5; R2 is an aromatic hydrocarbon radical or a C-bonded heterohydrocarbon radical and R3 is an aliphatic or C-bonded heteroaliphatic hydrocarbon radical; R2 and R3 are identical or different and are each an aliphatic or C-bonded heteroaliphatic hydrocarbon radical; R4 is an unsubstituted or C1-C6-alkyl-, C1-C6-alkoxy- or halogen-substituted hydrocarbon radical; and A is a secondary amino group, are ligands for metal complexes which are suitable as catalysts for homogeneous enantioselective hydrogenation.
摘要:
The invention relates to compounds of the formula 1, in which R1, R2, R3, Arom and PG have the meanings as indicated in the description. These compounds are valuable intermediates for the preparation of pharmaceutically active compounds.
摘要:
The present invention relates to a process for the preparation of compounds of Formula (I), wherein R1 is 1,3-dimethyl-butyl, 1,3,3-trimethyl-butyl or a group A1, wherein R3, R4 and R5 are each independently of the others hydrogen or C1-C4alkyl; and R2 is hydrogen; or R1 and R2 together from the group A2, wherein R6, and R7 are each independently of the other hydrogen or C1-C4alkyl; or R1 and R2 together from the group A3, wherein R5 and R9 are each independently of the other hydrogen or C1-C4alkyl; wherein a compound of Formula (II) wherein R1 and R2 are as defined for formula I and X is bromine or chlorine, is reacted with ammonia in the presence of a base and a catalytic amount of at least one palladium complex compound, wherein the palladium complex compound comprises at least one ferrocenyl-biphosphine ligand.
摘要:
The invention relates to compounds of the formula 1, in which R1, R2, R3, Arom and PG have the meanings as indicated in the description. These compounds are valuable intermediates for the preparation of pharmaceutically active compounds.