Synthesis Of Chiral Β-amino Alcohols Research Articles

Enantioselective synthesis of enantiopure β-amino alcohols via kinetic resolution and asymmetric reductive amination by a robust transaminase from Mycobacterium vanbaalenii

Chiral β-amino alcohols are very important chiral building block for preparing bioactive compounds for use in pharmaceutical and fine chemical industries. Synthesis of chiral β-amino alcohols by transaminase is big challenging due to the strict substrate specificities and very low activity of the enzyme. In this work, a (R)-selective ω-transaminase (MVTA) from Mycobacterium vanbaalenii was employed as a biocatalyst for the first time for the synthesis of chiral β-amino alcohol via kinetic resolution and asymmetric reductive amination. The enzyme was purified and characterized. Kinetic resolution of a set of racemic β-amino alcohols including two cyclic β-amino alcohols by MVTA was demonstrated, affording (R)-β-amino alcohols, (1S, 2S)-trans-2-aminocyclopentanol and (1R, 2S)-cis-1-amino-2-indanols in >99% ee and 50–62% conversion. Asymmetric reductive amination of three α-hydroxy ketones (10–300 mM) by MVTA was conducted, (S)-β-amino alcohols were obtained with >99% ee and 80–99% conversion. Preparation experiment for the reductive amination of 200 mM 2-hydroxyacetophenone by the resting cells of recombinant E. coli (MVTA) was proceeded smoothly and product (S)-2-amino-2-phenylethanol was obtained with 71% isolated yield, >99% ee and 68.6 g/L/d volumetric productivity. The current research proved that the MVTA is a robust enzyme for the preparation of chiral β-amino alcohol with high volumetric productivity.

Chiral Co(iii)–salen complex supported over highly ordered functionalized mesoporous silica for enantioselective aminolysis of racemic epoxides

New mesoporous chiral Co(iii)-catalyst has been synthesed and used in the synthesis of chiral β-amino alcohols with excellent yield and enantioselectivity (ee > 99%) under neat conditions at RT.

A new recyclable functionalized mesoporous SBA-15 catalyst grafted with chiral Fe(iii) sites for the enantioselective aminolysis of racemic epoxides under solvent free conditions

A mesoporous SBA-15 supported chiral Fe(iii)-catalyst was prepared and used for the synthesis of chiral β-amino alcohols with very good yields and enantioselectivities (ee upto 98%) under neat conditions at RT.

Regio- and Stereoselective Ring-Opening Reaction of Chiral Aziridines: A Facile Synthesis of Chiral β-Amino Alcohols

The reaction of chiral 2-alkylsubstituted aziridines (1a-d) with acetic acid afforded β-amino alcohols with an (S)-chiral center at the β position (with respect to oxygen). In contrast, a reaction of the same chiral aziridines with acetyl chloride followed by treatment with water gave β-amino alcohols that have an (S)-chiral center at the a position. In addition, the reaction of the same chiral aziridines with benzyl bromide followed by treatment with 2% sulfuric acid gave the β-amino alcohols with an (R)-chiral center at the a position. Thus, we could control the regioselectivity and stereoselectivity of the ring-opening reaction of chiral aziridines (1a-d).

Pd/La Complex foranti-Selective Catalytic Asymmetric Nitroaldol Reactions

A limited number of reports describe the anti-selective synthesis of chiral β-amino alcohols. This report describes the design of a simple and efficient catalyst with a broad substrate scope and practical applicability. The authors nicely demonstrate the short syntheses of two β-adrenoceptor agonists.