Enantioselectivity of Haloalkane Dehalogenases and its Modulation by Surface Loop Engineering
作者:Zbynek Prokop、Yukari Sato、Jan Brezovsky、Tomas Mozga、Radka Chaloupkova、Tana Koudelakova、Petr Jerabek、Veronika Stepankova、Ryo Natsume、Jan G. E. van Leeuwen、Dick B. Janssen、Jan Florian、Yuji Nagata、Toshiya Senda、Jiri Damborsky
DOI:10.1002/anie.201001753
日期:2010.8.16
In the loop: Engineering of the surfaceloop in haloalkanedehalogenases affects their enantiodiscrimination behavior. The temperature dependence of the enantioselectivity (lnE versus 1/T) of β‐bromoalkanes by haloalkanedehalogenases is reversed (red data points) by deletion of the surfaceloop; the selectivity switches back when an additional single‐point mutation is made. This behavior is not observed
Enantioselective synthesis of α-bromo acid derivatives and bromohydrins † from tartrate derived bromoacetals
作者:Scott A. Boyes、Alan T. Hewson
DOI:10.1039/b002106g
日期:——
Bromination of the acetals 4 derived from aryl alkyl ketones, ArCOR, and (2R,3R)-tartaric acid results in bromoacetals 5 with 78–90% de. Hydrolysis of those compounds with Ar = 4-methoxyphenyl or 3-bromo-4-methoxyphenyl results, after recrystallisation, in α-bromoketones 8 with 66–98% ee which are shown to undergo the Baeyer–Villiger oxidation to α-bromoesters 9 with minimal racemisation. α-Bromoketone
GC Separation of Enantiomers of Alkyl Esters of 2-Bromo Substituted Carboxylic Acids Enantiomers on 6-TBDMS-2,3-di-alkyl- β- and γ-Cyclodextrin Stationary Phases
作者:Ivan Špánik、Darina Kačeriaková、Jan Krupčík、Daniel Wayne Armstrong
DOI:10.1002/chir.22310
日期:2014.6
The gas chromatographic separation of enantiomers of 2‐Br carboxylicacid derivatives was studied on four different 6‐TBDMS‐2,3‐di‐O‐alkyl‐ β‐ and ‐γ‐CD stationaryphases. The differences in thermodynamic data ΔH and –ΔS} for the 15 structurally related racemates were evaluated. The influence of structure differences in the alkyl substituents covalently attached to the stereogenic carbon atom, as
PROCESS FOR THE PREPARATION OF 2-OXO-1-PYRROLIDINE DERIVATIVES
申请人:Surtees John
公开号:US20080009638A1
公开(公告)日:2008-01-10
The present invention relates to alternative processes for the preparation of 2-oxo-1-pyrrolidine derivatives of formula (I)
Particularly, the present invention relates to alternative processes for the synthesis of levetiracetam, brivaracetam and seletracetam.