Please use this identifier to cite or link to this item:
Main Title: Combined heterogeneous bio- and chemo-catalysis for dynamic kinetic resolution of (rac)-benzoin
Author(s): Nieguth, R.
ten Dam, J.
Petrenz, A.
Ramanathan, A.
Hanefeld, U.
Ansorge-Schumacher, M. B.
Type: Article
Language Code: en
Abstract: Dynamic kinetic resolution (DKR) of racemic starting material is a promising route to optically pure (S)-benzoin (2-hydroxy-1,2-di(phenyl)ethanone) and various symmetrical and unsymmetrical derivatives thereof. Here, this route was advanced towards technical scale synthesis using the basic (rac)-benzoin as model system. The reaction employed stereoselective transesterification of (S)-benzoin with lipase TL® from Pseudomonas stutzeri and racemization of (R)-benzoin with Metal-TUD-1, a metal-associated acidic meso-porous silicate, in pure organic solvent. Enzyme performance was improved by immobilization on Accurel MP1001 (yielding Acc-LipTL), and Zr-TUD-1 (Si/Zr = 25) was identified as most effective racemization catalyst. Compatibility in solvent and temperature dependency enabled performance in only one pot. DKR in toluene at 50 °C yielded conversions above 98% and an ee of >97% in only five hours. Stability of Acc-LipTL was further improved with polyethylene imine and the reaction system was then reused in five cycles, retaining a conversion of >99% and a product-ee of >98%. On a semi-preparative scale, the isolated yield of enantiopure (S)-benzoin butyrate was >98%. Thus, the system provides a good basis for synthesis of enantiopure benzoin, and potentially a broader range of aromatic α-hydroxy ketones.
Issue Date: 2014
Date Available: 21-Jun-2016
DDC Class: 540 Chemie und zugeordnete Wissenschaften
Journal Title: RSC Advances : an international journal to further the chemical sciences
Publisher: Royal Society of Chemistry
Publisher Place: Cambridge
Volume: 4
Issue: 85
Publisher DOI: 10.1039/c4ra06751g
Page Start: 45495
Page End: 45503
EISSN: 2046-2069
Appears in Collections:FG Technische Chemie » Publications

Files in This Item:
File Description SizeFormat 
c4ra06751g.pdf499.3 kBAdobe PDFThumbnail

This item is licensed under a Creative Commons License Creative Commons