Enzyme assisted synthesis of enantiomerically pure δ-lactones
摘要:
Both enantiomeric series of a wide variety of optically pure 6-alkylated delta-lactones - saturated as well as unsaturated - were prepared via an enzyme mediated route. The key reaction step is the nucleophilic ring opening of enantiomerically pure alkyl-oxiranes, accessible via the corresponding beta-hydroxythioethers which can be obtained enantiomerically pure via enzyme catalyzed kinetic resolutions.
Asymmetric hydrolytic kinetic resolution with recyclable polymeric Co(<scp>iii</scp>)–salen complexes: a practical strategy in the preparation of (S)-metoprolol, (S)-toliprolol and (S)-alprenolol: computational rationale for enantioselectivity
作者:Tamal Roy、Sunirmal Barik、Manish Kumar、Rukhsana I. Kureshy、Bishwajit Ganguly、Noor-ul H. Khan、Sayed H. R. Abdi、Hari C. Bajaj
DOI:10.1039/c4cy00594e
日期:——
epoxide (up to 46% compared to 50% theoretical yield) along with high enantioselectivity (up to 99%) were obtained in most cases using catalyst 1. Further studies showed that catalyst 1 could retain its catalyticactivity for six cycles under the present reaction conditions without any significant loss in activity or enantioselectivity. To show the practical applicability of the above synthesized catalyst
Catalytic asymmetric epoxidations with chiral iron porphyrins
作者:John T. Groves、Richard S. Myers
DOI:10.1021/ja00356a016
日期:1983.9
Epoxydation asymetrique d'olefines prochirales par des porphyrines de fer chirales et par des composes iodosyles
环氧不对称 d'烯烃 prochirales par des porphyrines de fer chirales et par des composes iodosyles
Direct Stereospecific Amination of Alkyl and Aryl Pinacol Boronates
作者:Scott N. Mlynarski、Alexander S. Karns、James P. Morken
DOI:10.1021/ja305448w
日期:2012.10.10
The directamination of alkyl and aryl pinacol boronates is accomplished with lithiated methoxyamine. This reaction directly provides aliphatic and aromatic amines, stereospecifically, and without preactivation of the boronate substrate.
Biocatalytic Cascade for the Synthesis of Enantiopure β-Azidoalcohols and β-Hydroxynitriles
作者:Joerg H. Schrittwieser、Iván Lavandera、Birgit Seisser、Barbara Mautner、Wolfgang Kroutil
DOI:10.1002/ejoc.200900091
日期:2009.5
one-pot reaction sequence starting from prochiral α-chloroketones leading to enantiopure β-azidoalcohols and β-hydroxynitriles is described. Asymmetric bioreduction of α-chloroketones by hydrogen transfer catalysed by an alcohol dehydrogenase (ADH) established the stereogenic centre in the first step to furnish enantiopure chlorohydrin intermediates. Subsequent biocatalysed ring closure to the epoxide
Stereo-Complementary Two-Step Cascades Using a Two-Enzyme System Leading to Enantiopure Epoxides
作者:Birgit Seisser、Iván Lavandera、Kurt Faber、Jeffrey H. Lutje Spelberg、Wolfgang Kroutil
DOI:10.1002/adsc.200700027
日期:2007.6.4
A novel one-pot, two-step, two-enzymecascade is described. Pro-chiral α-chloro ketones are stereoselectively reduced to the corresponding halohydrins as an intermediate by a biocatalytic hydrogen transfer process. The intermediate is transformed to the corresponding epoxide by a non-enantioselective halohydrin dehalogenase. Thus, by combining a Prelog- or anti-Prelog alcohol dehydrogenase with a non-selective