Patent classifications
C07B53/00
TETRADENTATE LIGAND, AND PRODUCTION METHOD THEREFOR, SYNTHETIC INTERMEDIATE THEREOF, AND TRANSITION METAL COMPLEX THEREOF
The present invention relates to: a compound as a ligand in a variety of catalytic organic synthetic reactions; a method for producing the compound; a synthetic intermediate of the compound; and a transition metal complex which has the compound as a ligand. The compound includes a compound represented by the following general formula (1.sup.A):
##STR00001##
Method for the production of praziquantel and precursors thereof
The present invention provides methods of preparing Praziquantel, in particular (R)-Praziquantel and analogues thereof in a stereoselective manner. One method involves asymmetric hydrogenation of the following intermediate compound ##STR00001##
and subsequent cyclization.
Method for the production of praziquantel and precursors thereof
The present invention provides methods of preparing Praziquantel, in particular (R)-Praziquantel and analogues thereof in a stereoselective manner. One method involves asymmetric hydrogenation of the following intermediate compound ##STR00001##
and subsequent cyclization.
ION PAIR CATALYSIS OF TUNGSTATE AND MOLYBDATE
The present invention relates to ion pair catalysts (I) comprising the cationic bisguanidinium ligand (A) and diperoxomolybdate anion (B). The present invention also relates to ion pair catalysts (III) comprising the cationic bisguanidinium ligand (C) and peroxotungstate anion (D). It further relates to the use of the said catalysts in the manufacture of enantiomerically enriched sulfoxides.
##STR00001##
ION PAIR CATALYSIS OF TUNGSTATE AND MOLYBDATE
The present invention relates to ion pair catalysts (I) comprising the cationic bisguanidinium ligand (A) and diperoxomolybdate anion (B). The present invention also relates to ion pair catalysts (III) comprising the cationic bisguanidinium ligand (C) and peroxotungstate anion (D). It further relates to the use of the said catalysts in the manufacture of enantiomerically enriched sulfoxides.
##STR00001##
Chiral dihydrobenzooxaphosphole ligands and synthesis thereof
This invention relates to novel phosphorous ligands useful for organic transformations. Methods of making and using the ligands in organic synthesis are described. The invention also relates to processes for preparing the novel ligands.
Chiral dihydrobenzooxaphosphole ligands and synthesis thereof
This invention relates to novel phosphorous ligands useful for organic transformations. Methods of making and using the ligands in organic synthesis are described. The invention also relates to processes for preparing the novel ligands.
Synthesis process for chiral cyclopropyl ethynyl tertiary alcohol compound
Provided is a synthesis process for a chiral cyclopropyl ethynyl tertiary alcohol compound, where a chiral amino alcohol or a chiral amino diol is reacted in the presence of an alkaline reagent and a salt to obtain an optically active propynyl alcohol compound. In particular, the process includes (1) reacting cyclopropyl acetylene with a chiral inducing agent, a chiral auxiliary reagent and zinc halide in an organic solvent in the presence of an alkaline reagent and a sulfonate or a sulphinate to obtain a first reaction mixture; (2) reacting the resultant first reaction mixture with 5-chloro-2-aminotrifluorobenzophenone to form (S)-2-amino-5-chloro--cyclopropyl acetylene--trifluoromethylbenzyl alcohol. The process avoids an organic zinc reagent and a Grignard reagent, and has the advantages of safe production, an environmentally friendly route, low production costs, a high resultant product yield, a high chiral ee value and is suitable for industrial production.
Synthesis process for chiral cyclopropyl ethynyl tertiary alcohol compound
Provided is a synthesis process for a chiral cyclopropyl ethynyl tertiary alcohol compound, where a chiral amino alcohol or a chiral amino diol is reacted in the presence of an alkaline reagent and a salt to obtain an optically active propynyl alcohol compound. In particular, the process includes (1) reacting cyclopropyl acetylene with a chiral inducing agent, a chiral auxiliary reagent and zinc halide in an organic solvent in the presence of an alkaline reagent and a sulfonate or a sulphinate to obtain a first reaction mixture; (2) reacting the resultant first reaction mixture with 5-chloro-2-aminotrifluorobenzophenone to form (S)-2-amino-5-chloro--cyclopropyl acetylene--trifluoromethylbenzyl alcohol. The process avoids an organic zinc reagent and a Grignard reagent, and has the advantages of safe production, an environmentally friendly route, low production costs, a high resultant product yield, a high chiral ee value and is suitable for industrial production.
METHODS FOR PRODUCING OPTICALLY ACTIVE VALERIC ACID DERIVATIVES
A method for producing a compound (4), which comprises allowing a compound (1) to react with hydrogen gas in an inert solvent, in the presence of a specific chiral ligand and a ruthenium catalyst, or in the presence of an asymmetric transition metal complex catalyst previously generated from the chiral ligand and the ruthenium catalyst.
##STR00001##