- Heterocycles 38. Biocatalytic synthesis of new heterocyclic mannich bases and derivatives
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This paper describes the biocatalytic synthesis of new Mannich bases containing various heterocyclic rings (thiazole, furane, thiophene, pyridine) by applying the lipase catalyzed trimolecular condensation of the corresponding heterocyclic aldehydes with acetone and primary aromatic amines, in mild and eco-friendly reaction conditions. The obtained Mannich bases were acylated to their corresponding N-acetyl derivatives. All compounds were characterized by 1H-NMR, 13C-NMR and MS spectrometry.
- Leonte, Denisa,Bencze, László Csaba,Paizs, Csaba,Irimie, Florin Dan,Zaharia, Valentin
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p. 12300 - 12313
(2015/08/18)
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- Heterocycles 32. Efficient kinetic resolution of 1-(2-arylthiazol-4-yl) ethanols and their acetates using lipase B from Candida antarctica
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In this paper we describe the chemoenzymatic synthesis of new enantiomerically enriched (R)- and (S)-1-(2-arylthiazol-4-yl)ethanols and their acetates by enzymatic enantioselective acetylation of the racemic alcohols rac-2a-d and by methanolysis of the corresponding racemic esters rac-3a-d mediated by lipase B from Candida antarctica (CaL-B) in non-aqueous media. In terms of stereoselectivity and activity, both procedures, acylation and alcoholysis, gave similar good results (50% conversion, E 〉 200). The absolute configuration of the kinetic resolution products was determined by a detailed 1H NMR study of the Mosher's derivatives of (S)-2b.
- Hapau, Denisa,Brem, Juergen,Moisa, Madalina,Tosa, Monica-Ioana,Irimie, Florin Dan,Zaharia, Valentin
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