Chiral Lewis base promoted trichlorosilane reduction of ketimines. An enantioselective organocatalytic synthesis of chiral amines
摘要:
The reduction of the carbon-nitrogen double bond is an important transformation. Here we report our studies on a family of chiral organic catalysts able to promote the stereoselective reduction of ketimines with trichlorosilane. The very cheap, metal-free catalysts were easily prepared in one step from commercially available products, namely a chiral aminoalcohol and picolinic acid derivatives. The catalyst structure was extensively modified in a study that allowed to identify an extremely active species, able to promote the reduction on a large variety of substrates with high efficiency (up to 95% ee). A three component methodology has been also developed, where the enantiomerically enriched amine was isolated after performing the reaction by mixing a ketone and an amine in the presence of trichlorosilane and the catalyst. Its synthetic potentiality was demonstrated by employing the present metal-free catalytic procedure in the preparation of (S)-metolachlor, a potent and widely used herbicide. (C) 2009 Elsevier Ltd. All rights reserved.
Structure, Activity and Stereoselectivity of NADPH-Dependent Oxidoreductases Catalysing the<i>S</i>-Selective Reduction of the Imine Substrate 2-Methylpyrroline
作者:Henry Man、Elizabeth Wells、Shahed Hussain、Friedemann Leipold、Sam Hart、Johan P. Turkenburg、Nicholas J. Turner、Gideon Grogan
DOI:10.1002/cbic.201402625
日期:2015.5.4
production of chiral amines: The structures of imine reductases (IREDs) from B. cereus and N. halophila that are S‐selective for the reduction of 2‐methylpyrroline (2MPN) reveal conservation of residues in this IRED subgroup. These structures permit comparison with those of IREDs that are R‐selective for 2MPN reduction, revealing structural differences in the active sites.
[EN] 1-AZA-BICYCLO [2.2.2] OCTANE DERIVATIVES USEFUL AS MUSCARINIC RECEPTOR ANTAGONISTS<br/>[FR] DÉRIVÉS DE 1-AZA-BICYCLO [2.2.2] OCTANE UTILES EN TANT QU'ANTAGONISTES DES RÉCEPTEURS MUSCARINIQUES
申请人:ARGENTA DISCOVERY LTD
公开号:WO2009153536A1
公开(公告)日:2009-12-23
The invention provides named compounds of formula (I), pharmaceutical compositions containing them, a process for preparing the pharmaceutical compositions and their use in therapy.
A general and enantiodivergent method for the asymmetric synthesis of piperidine alkaloids: concise synthesis of (R)-pipecoline, (S)-coniine and other 2-alkylpiperidines
作者:Juan Etxebarria、Jose L. Vicario、Dolores Badía、Luisa Carrillo
DOI:10.1016/j.tet.2007.08.067
日期:2007.11
A simple and very efficient protocol for the preparation of highly enantioenriched 2-alkylpiperidines has been set up, which allows the preparation of the final heterocycles with any wanted configuration at the stereogenic center starting from the same starting material. The key step of the synthesis relies on a diastereodivergent aza-Michael reaction protocol using the readily available and cheap
Cp*Ir Complex-Catalyzed <i>N</i>-Heterocyclization of Primary Amines with Diols: A New Catalytic System for Environmentally Benign Synthesis of Cyclic Amines
作者:Ken-ichi Fujita、Takeshi Fujii、Ryohei Yamaguchi
DOI:10.1021/ol048619j
日期:2004.9.1
[reaction: see text] A new efficient method for the N-heterocyclization of primaryamines with diols catalyzed by a CpIr complex was developed. A variety of five-, six-, and seven-membered cyclic amines were synthesized in good to excellent yields with the formation of only water as a byproduct. A two-step asymmetric synthesis of (S)-2-phenylpiperidine was also achieved using (R)-1-phenylethylamine