Total synthesis of(-)-grayanotoxin III (3), a unique tetracyclic diterpene isolated from the leaves of various plants of the family Ericaceae, has been successfully accomplished featuring the highly stereoselective cyclization reactions induced by SmI2.
Enzymatic kinetic resolution of organochalcogenides in supercritical CO2
摘要:
1-(Phenylthio)-, 1-(phenylseleno)- and 1-(phenyltelluro)-propan-2-ol were efficiently resolved by CAL-B in sc-CO2. (C) 2011 Elsevier Ltd. All rights reserved.
Enantioselective Cross-Coupling of <i>meso</i>-Epoxides with Aryl Halides
作者:Yang Zhao、Daniel J. Weix
DOI:10.1021/jacs.5b01909
日期:2015.3.11
The first enantioselective cross-electrophile coupling of aryl bromides with meso-epoxides to form trans-β-arylcycloalkanols is presented. The reaction is catalyzed by a combination of (bpy)NiCl2 and a chiral titanocene under reducing conditions. Yields range from 57 to 99% with 78–95% enantiomeric excess. The 30 examples include a variety of functional groups (ether, ester, ketone, nitrile, ketal
Asymmetric reduction of ketones by Geotrichum candidum in the presence of AmberliteTM XAD, a solid organic solvent
作者:Kaoru Nakamura、Mikio Fujii、Yoshiteru Ida
DOI:10.1039/b005204n
日期:——
A hydrophobic polymer, Amberlite™ XAD, was used as material to control the stereochemical course of microbial reductions. In the presence of XAD, simple aliphatic and aromatic ketones were reduced to the corresponding (S)-alcohols in excellent enantiomeric excess (ee) while low enantioselectivities were observed in the absence of the polymer.
A facile chemoenzymatic route to enantiomerically pure oxiranes: building blocks for biologically active compounds
作者:Ulrich Goergens、Manfred P. Schneider
DOI:10.1039/c39910001064
日期:——
The enantiomerically purebuildingblocks (R)-and (S)-1–4 were prepared both by enantioselective, enzymatic hydrolysis and by acyl transfer, and subsequently converted into the corresponding enantiomerically pure oxiranes (R)- and (S)-7 and 8.
Production of (R)-1-(1,3-dithian-2-yl)propan-2-ol by microbial reduction
作者:Rosanna Bernardi、Rosanna Cardillo、Dario Ghiringhelli、Orso Vajna de Pava
DOI:10.1039/p19870001607
日期:——
The reduction of several selected carbonyl compounds with growing cultures of Streptomyces sp., Aspergillus niger, and Geotrichum candidum has been studied. The production of (R)-1-(1,3-dithian-2-yl)propan-2-ol of high enantiomeric purity has been achieved by reduction of dithianylacetone with a Streptomyces sp.
pH DEPENDENT OXIDATION-REDUCTION OF 1-BENZENESULFENYL-2-PROPANONE AND ITS OXIDES BY A MICROORGANISM
作者:Hiromichi Ohta、Yasuo Kato、Gen-ichi Tsuchihashi
DOI:10.1246/cl.1986.581
日期:1986.4.5
Incubation of 1-benzenesulfenyl-2-propanone with Corynebacterium equi IFO 3730 in a weakly acidic medium afforded (S)-1-benzenesulfenyl-2-propanol. On the contrary, when the cultivation was carried out at pH 8 with the same bacterium, only the (S)-alcohol was transformed into the starting ketone, the (R)-alcohol being recovered intact. The similar enantioselectivities were also observed in the reaction of 1-benzenesulfinyl-2-propanone.