Yonghui Zhang

Kinetic resolution of hydroxyalkanephosphonates catalyzed by candida antarctica lipase B in organic media

A series of hydroxyalkanephosphonates were studied as substrates for CALB catalyzed acetylation with emphasis on enantioselectivity and chemical structure of substrates. Some hydroxyalkanephosphonates could be resolved successfully to give both (R)- and (S)-isomers with high enantiomeric excess.

Candida rugosa lipase-catalyzed enantioselective hydrolysis in organic solvents. Convenient preparation of optically pure 2-hydroxy-2-arylethanephosphonates

A convenient enzymatic method is presented for the preparation of optically pure 2-hydroxy-2-arylethanephosphonates. It is proved that 2-butyryloxy-2-arylethanephosphonates can be enantioselectively hydrolyzed in diisopropyl ether equilibrated with water to give both isomers in high yield and excellent enantiomeric excess.

Enzymatic synthesis of optically active trifluoromethylated 1- and 2-hydroxyalkanephosphonates ☆

Abstract Convenient enzymatic methods have been developed for the preparation of chiral 1- and 2-hydroxyalkanephosphonates bearing a trifluoromethyl moiety with high enantiomeric excess via Candida antarctica lipase B-, Mucor miehei lipase-catalyzed alcoholysis and C. rugosa lipase-catalyzed hydrolysis in organic media. The enantiomeric excess of such trifluoromethylated carbinols was determined using quinine as a chiral solvating agent. The catalytic preference was assigned according to the Kusumi–Ohtani method.

Enzymatic synthesis of optically active δ-hydroxy-β-ketoalkanephosphonates ☆

A novel and enantioselective approach to δ-hydroxy-β-ketoalkanephosphonates has been developed via CALB-catalyzed enantioselective acetylation and CRL-catalyzed enantioselective hydrolysis.

Enzymatic synthesis of optically active 1-and 2-aminoalkanephosphonates

A number of 1-and 2-aminoalkanephosphonates were resolved with high ENANTIOSELECTIVITY BY Candida antarctica lipase B-catalyzed acetylation. By this method, optically pure aminoalkanephosphonates and amidoalkanephosphonates, the precursors of the corresponding aminoalkanephosphonic

A chemoenzymatic approach to optically active 5-hydroxy-3-oxo-carboxylates

Enzymatic hydrolysis was applied to the preparation of certain chiral 5-hydroxy-3-oxo-carboxylates that are potential precursors for natural product synthesis via the formation of lactone derivatives and tetrahydropyran rings.

Biocatalytical Kinetic Resolution of Hydroxyalkanephosphonates

Chiral hydroxyalkanephosphonic acids have received significant attention in recent years due to their potential biological activities and applications as chiral synthon in natural products synthesis. As found by us, a large number of ketoand diketo-phosphonates could be converted easily by baker’s yeast to chiral hydroxyalkanephosphonates in good yield and ee value with excellent regioand stereoselectivity depending on the nature of substituents located closed to carbonyl group. Unfortunately, 1-oxyalkanephosphonates resisted to such bioreductive system. In this article, a biocatalytical kinetic resolution of 1-hydroxyalkanephosphonates by Candida antartica lipase B (CALB) was reported. Our experimental data demonstrated that 1-hydroxyethanephosphonate underwent catalytic acylation with vinyl acetate as acyl donor in organic solvent using CALB as catalyst provided both (S)acylhydroxyethanephosphonate and (R)hydroxyethanephosphonate with 87–98% ee value. Under optimized conditions, (S)hydroxycomponent was exclusively acylated almost in quantitative yield.