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
A chemoenzymatic access to optically active 1,2-epoxides
作者:Ching-Shih Chen、Yeuk-Chuen Liu
DOI:10.1016/s0040-4039(01)93924-3
日期:1989.1
Lipase-catalyzed transacylation in organic media was employed to produce opticallyactive α-hydroxy tosylate which could be readily converted to the corresponding 1,2-epoxides with high optical purity.
Highly Selective Hydrolytic Kinetic Resolution of Terminal Epoxides Catalyzed by Chiral (salen)Co<sup>III</sup> Complexes. Practical Synthesis of Enantioenriched Terminal Epoxides and 1,2-Diols
作者:Scott E. Schaus、Bridget D. Brandes、Jay F. Larrow、Makoto Tokunaga、Karl B. Hansen、Alexandra E. Gould、Michael E. Furrow、Eric N. Jacobsen
DOI:10.1021/ja016737l
日期:2002.2.1
The hydrolytickineticresolution (HKR) of terminal epoxides catalyzed by chiral (salen)Co(III) complex 1 x OAc affords both recovered unreacted epoxide and 1,2-diol product in highly enantioenriched form. As such, the HKR provides general access to useful, highly enantioenriched chiral building blocks that are otherwise difficult to access, from inexpensive racemic materials. The reaction has several
Hydrolytic Kinetic Resolution of Epoxides Catalyzed by Chromium(III)-endo,endo-2,5-diaminonorbornane-salen [Cr(III)-DIANANE-salen] Complexes. Improved Activity, Low Catalyst Loading
作者:Albrecht Berkessel、Erkan Ertürk
DOI:10.1002/adsc.200606181
日期:2006.12
The hydrolytickineticresolution (HKR) of terminal epoxides, using chiral chromium(III)-salen catalysts based on DIANANE (endo,endo-2,5-diaminonorbornane), was studied. A broad substrate scope was found for the chromium(III)-DIANANE catalysts, and very low loadings (down to 0.05 mol %) were needed to achieve high enantiomeric purities of both the remaining epoxides and the product diols (up to >99 %
ortho‐substituted phenyl glycidyl ethers and para‐nitrostyrene oxide. Worthy of note is that the substrate structure remarkably affected the enantioselectivities of the enzyme, as a reversed (S)‐enantiopreference was unexpectedly observed for the ortho‐nitrophenyl glycidyl ether. As a proof‐of‐concept, five enantiopure epoxides (>99% ee) were obtained in high yields, and a gram‐scale preparation of