[EN] ENANTIONSELECTIVE PROCESSES TO INSECTICIDAL 3-ARYL-3-TRIFLUOROMETHYL-SUBSTITUTED PYRROLIDINES [FR] PROCÉDÉS ÉNANTIOSÉLECTIFS POUR DES INSECTICIDES DE PYRROLIDINES 3-ARYL-3-TRIFLUOROMÉTHYL-SUBSTITUÉES
A new class of asymmetric phase-transfer catalysts derived from Cinchona alkaloids — Application in the enantioselective synthesis of α-amino acids
作者:Barry Lygo、Philip G. Wainwright
DOI:10.1016/s0040-4039(97)10293-3
日期:1997.12
new class of Cinchona alkaloid-derived quaternary ammonium phase-transfercatalysts bearing a N-anthracenylmethyl function are presented. These catalysts show high stereocontrol in the asymmetric alkylation of a benzophenone-derived glycine-imine, and application of this process to the enantioselectivesynthesis of a range of α-aminoacid esters (e.e. 67–94%) is investigated.
Diastereoselective and Enantioselective Epoxidation of Acyclic β-Trifluoromethyl-β,β-Disubstituted Enones by Hydrogen Peroxide with a Pentafluorinated Quinidine-Derived Phase-Transfer Catalyst
efficient catalytic asymmetric epoxidation of β‐trifluoromethyl‐β,β‐disubstituted unsaturated ketones has been achieved by a pentafluorine‐substituted phase‐transfer catalyst with hydrogenperoxide (30%). Thus, the β‐trifluoromethyl‐α,β‐epoxy ketones with a quaternary carbon centre were obtained in excellent diastereoselectivities (up to 100:1 dr) and excellent enantioselectivities (up to 99.7% ee). Low catalyst
A general catalytic enantioselective trifluoromethylation of aromatic aldehydes using (IPr)CuF and quinidine-derived quaternary ammonium salt as catalysts has been developed. A wide range of aromatic aldehydes are converted to the corresponding products in up to 92% yield and 81% ee at 2 mol% of catalyst loading. (C) 2013 Elsevier B.V. All rights reserved.
Catalytic asymmetric epoxidation of enones under phase-transfer catalyzed conditions
The development of the catalytic asymmetric epoxidation of enones promoted by aqueous H2O2 with chiral quaternary ammonium salts is described. The reaction smoothly proceeded to give alpha,beta-epoxyketones with satisfactory enantioselectivities in both the trans and cis enone systems (up to 92% ee) by use of cinchonine or quinidine derivatives (5 mol%) as phase transfer catalysts. (C) 2002 Elsevier Science Ltd. All tights reserved.
Asymmetric dearomative spirolactonization of naphthols using λ3-iodanes under chiral phase-transfer catalysis
作者:Kevin Antien、Guillaume Viault、Laurent Pouységu、Philippe A. Peixoto、Stéphane Quideau
DOI:10.1016/j.tet.2017.04.028
日期:2017.6
The asymmetric phase-transfer catalytic effect of chiral Cinchona alkaloid-derived quaternary ammonium salts was investigated in the context of the λ3-iodane-mediated dearomative spirolactonization of naphthols. The scope and limitations of this methodology were evaluated using various substrates, which were converted into spirolactones in good yields and with enantiomeric excesses up to 58%.