330results about "Carboxylic acid amides optical isomer preparation" patented technology

The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives which are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of a prochiral beta amino acrylic acid derivative substrate in the presence of a transition metal precursor complexed with a chiral ferrocenyl diphosphine ligand.

A compound of formula 1awhich is useful for treating reperfusion injury, and salts, prodrugs, and related compounds.

A compound of formula 1a which is useful for treating reperfusion injury, and salts, prodrugs, and related compounds.

The invention encompasses processes for the synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid, (S)-Pregabalin, and intermediates of (S)-Pregabalin.

The invention relates to a chiral spiro phosphine-nitrogen-sulfur tridentate ligand and a preparation method and application thereof. The chiral spiro phosphine-nitrogen-sulfur tridentate ligand is a compound with a formula I or formula II, or a racemate or optical isomer thereof, or a catalytically-acceptable salt thereof, and has the main structure characteristic of having a chiral spiro indan skeleton and a sulfoether group. The chiral spiro phosphine-nitrogen-sulfur tridentate ligand can be synthesized from chiral starting materials of 7-diaryl / alkyl phosphino-7'-amino-1,1'-spiro indan compound with a spiro skeleton. The chiral spiro phosphine-nitrogen-sulfur tridentate ligand and transition metal salt form a complex, which can be used in catalysis of an asymmetric catalytic hydrogenation reaction of a carbonyl compound. Especially, the iridium complex shows high catalytic activity (catalyst amount of 0.0002% mol) and enantioselectivity (up to 99.9%ee) in asymmetric hydrogenation reaction of beta-alkyl-beta-keto ester, and has practical value.

The present invention is directed to a practical process for the preparation of an enamide (II) by palladium catalyzed coupling of a primary amide (IV) with a compound of structural formula (III), as shown below: As well as to crystalline forms of a compound produced by this process, in particular, an anhydrous crystal form, Form B, and crystalline solvates falling into three patterns, Type 1, Type 2, and Type 3, and crystalline intermediate compounds produced in the process. Still further, the present invention relates to the stereoselective reduction of the tetrasubstituted enamide (II) to the corresponding amide (I).