A base-controlled chemoselective transfer hydrogenation of α,β-unsaturated ketones catalyzed by [IrCp*Cl<sub>2</sub>]<sub>2</sub> with 2-propanol
作者:Shu-jie Chen、Guo-ping Lu、Chun Cai
DOI:10.1039/c5ra00484e
日期:——
A simple homogeneous catalyst system based on commercially available [IrCp*Cl2]2 has been developed for the transfer hydrogenation of α,β-unsaturated ketones.
[EN] A METHOD FOR PREPARING SULFUR-CONTAINING COMPOUNDS<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION DE COMPOSÉS CONTENANT DU SOUFRE
申请人:ROYAL COLLEGE OF SURGEONS IE
公开号:WO2010066450A1
公开(公告)日:2010-06-17
The invention provides a method for preparing sulfur-containing compounds, the method comprising reacting a donor compound comprising at least one sulfur having at least one lone pair of electrons, with an acceptor compound; wherein the reaction occurs in the presence of an amine, optionally an amine catalyst, capable of activating the sulfur having at least one lone pair of electrons; and wherein the reaction occurs via the formation of an transient intermediate species, optionally a transient intermediate species, between the amine, optionally the amine catalyst and the donor compound; and wherein the donor compound is selected from the group consisting of a sulfurous acid, a sulfenic acid and a sulfinic acid or a salt, ester or amide of a sulfurous acid, a sulfenic acid and a sulfinic acid. The invention also provides sulfur-containing compounds of the formula: wherein R is selected from: (a) 1 -(4-Nitro-phenyl)-3-oxo-3-phenyl-propane; (b) 2-(3-Methyl-4-nitro-isoxazol-5-yl)-1 -phenyl-ethane; (c) 1-(4-Methoxy-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; (d) 2-(3-Methyl-4-nitro-isoxazol-5-yl)-1-(4-nitro-phenyl)-ethane; (e) 1-(4-Fluoro-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; (f) 1 -(4-Chloro-phenyl)-2-(3-methyl-4-nitro-isoxazol-5-yl)-ethane; and (g) 3-Oxo-cyclohexane. Finally, the invention provides use of chiral sulfur-containing compounds obtainable by the above-mentioned method or chiral sulfur-containing compounds as mentioned above for the resolution of racemic mixtures of amines.
Chiral aldehyde catalysis is uniquely suitable for the direct asymmetric α-functionalization of N-unprotected amino acids, because aldehydes can reversibly form imines. However, there have been few successful reports of these transformations. In fact, only chiral aldehyde catalyzed aldol reactions of amino acids and alkylation of 2-amino malonates have been reported with good chiral induction. Here
4-HO-TEMPO-Catalyzed Redox Annulation of Cyclopropanols with Oxime Acetates toward Pyridine Derivatives
作者:Jun-Long Zhan、Meng-Wei Wu、Dian Wei、Bang-Yi Wei、Yu Jiang、Wei Yu、Bing Han
DOI:10.1021/acscatal.9b00832
日期:2019.5.3
for the synthesis of pyridines through the annulation of cyclopropanols and oxime acetates has been developed. This protocol features good functional group tolerance and high chemoselectivity and also promises to be efficient for the late-stage functionalization of skeletons of drugs and natural products. Mechanism studies indicate that the reaction involves the in situ generated α,β-unsaturated ketones
Rasta Resin-PPh3-NBniPr2 and its Use in One-Pot Wittig Reaction Cascades
作者:Yan Teng、Jinni Lu、Patrick H. Toy
DOI:10.1002/asia.201100721
日期:2012.2.6
reagent has been prepared and used effectively in a variety of one‐pot Wittigreactions. The design of this reagent resolved a deficiency of a previously reported related material, and allowed it to perform more efficiently in such reactions. Furthermore, it was readily recyclable, and was also successfully applied in cascade processes involving one‐pot Wittigreactions followed by either a conjugate