486460-00-8Relevant articles and documents
Application of the asymmetric hydrogenation of enamines to the preparation of a beta-amino acid pharmacophore
Kubryk, Michele,Hansen, Karl B.
, p. 205 - 209 (2006)
(3R)-3-[N-(tert-Butoxycarbonyl)amino]-4-(2,4,5-trifluorophenyl)butanoic acid 7a has been synthesized by an asymmetric hydrogenation of enamine ester 3 using chiral ferrocenyl ligands I and II in conjunction with [Rh(COD)Cl] 2. The direct reduction of 3 provides amino ester 1b in 93% ee, which was isolated as an (S)-camphorsulfonic acid salt to upgrade the enantiomeric excess to >99%. A more concise approach was developed involving the in situ protection of 1b using di-tert-butyldicarbonate. This approach provided the desired N-Boc amino ester 7b directly from the hydrogenation with 97% ee, which was upgraded to >99% ee upon crystallization.
Preparation method of chiral 4 - aryl - β β-amino acid derivative
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, (2021/11/14)
Provided is a method for preparing a chiral 4-aryl-β-amino acid derivative. The preparation method comprises hydrogenating an enamine compound having a structure as shown in Formula III in an organic solvent in the presence of a catalyst containing a transition metal and BIBOPs. The preparation method of the present invention uses a small amount of a selected asymmetric catalyst, and has a simple operation, mild reaction conditions, a high yield, a high stereoselectivity, and better industrial application and economic values.
AN IMPROVED PROCESS FOR THE PREPARATION OF SITAGLIPTIN AND ITS INTERMEDIATES
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, (2020/05/29)
The present invention relates to a process for the preparation of novel intermediates useful for the preparation of Sitagliptin or its pharmaceutically acceptable salts. The present invention relates to an efficient process for the preparation of Sitagliptin intermediates. The present invention relates to an improved process for the preparation of Sitagliptin or its pharmaceutically acceptable salts.