Design and Evaluation of Inclusion Resolutions, Based on Readily Available Host Compounds
作者:Simona Müller、Marcel Cyrus Afraz、René de Gelder、Gerry J. A. Ariaans、Bernard Kaptein、Quirinus B. Broxterman、Alle Bruggink
DOI:10.1002/ejoc.200400613
日期:2005.3
of enantiomers through selective crystallisation of diastereomeric inclusioncompounds can extend the scope of traditional racemate resolution beyond salt forming compounds. To assess the practical value of this approach the literature was carefully screened and promising results were checked. Also an extensive range of new inclusion hosts suitable for resolution processes, derived from simple hydroxyand
Construction of a Chiral β-Fluoroamine by Asymmetric Mannich Reaction of 2-Fluoroindanone with Pyrazolinone Ketimines
作者:Weizhi Gu、Jindong Li、Kuiliang Li、Qi Sun、Tong Li、Zhenggen Zha、Zhiyong Wang
DOI:10.1021/acs.joc.2c02040
日期:——
The asymmetricMannichreaction of 2-fluoroindanone with ketimine was developed under the catalysis of a kind of chiral copper complex, affording a chiral tetrahedral center containing fluorine. A series of β-fluoroamine derivatives can be obtained in excellent yields (73–94%) with high diastereoselectivities (>99:1 dr) and enantioselectivities (89–99%). The possible transition state was supported
Enantioselective and Regioselective Friedel-Crafts Alkylation of Pyrroles with Nitroalkenes Catalyzed by a Tridentate Schiff Base-Copper Complex
作者:Fengfeng Guo、Dalu Chang、Guoyin Lai、Tao Zhu、Shunshun Xiong、Sujing Wang、Zhiyong Wang
DOI:10.1002/chem.201102206
日期:2011.9.26
On a (pyr)role: A mild and highly efficientcatalytic system has been developed for the asymmetric Friedel–Crafts alkylation of pyrroles with nitroalkenes (see scheme). High yields, and excellent enantioselectivities and regioselectivities were obtained for a broad range of substrates. The synthetic utility of this methodology and mechanisticstudies involving a novel, negative, nonlinear effect are
cis-Selective cyclopropanations using chiral 5,5-diaryl bis(oxazoline) catalysts
作者:Karen Alexander、Stuart Cook、Colin L Gibson
DOI:10.1016/s0040-4039(00)01232-6
日期:2000.9
bis(oxazolines) have been prepared and used as ligands in the copper catalysed asymmetriccyclopropanation of styrene. Unusually, for bis(oxazolines), the diastereoselectivity of the process favoured the cis cyclopropanes with diastereomeric ratios of up to 65:35 being realised. The cis selectivity of the process was rationalised in terms of repulsion between the alkene substituent and the pro-R 5-aryl group