Acylations and aldol-type reactions of cyclopropyl α-sulfonylcarbanions formed from gave [(1R∗,2R∗)-6 and (1R∗,2R∗)-8] in high yields, respectively, but no diastereoisomeric were formed. The carbanion generated from led to rapid isomerization to provide a single diastereoisomeric .
Abstract Some new trans-aryl cyclopropylsulfones (II) have been prepared by the cycloaddition of dimethylsulfoxonium methylide to trans-styryl arylsulfones (I) by two different methods. It is observed that the reaction in presence of a phase transfer catalyst proceeds in a facile manner.
Stereocontrolled Synthesis of <i>trans</i>-Cyclopropyl Sulfones from Terminal Epoxides
作者:Christopher D. Bray、Giorgio de Faveri
DOI:10.1021/jo100844g
日期:2010.7.2
Treatment of a range of (enantiopure) epoxides with the sodium salt of diethyl (phenylsulfonyl)methylphosphonate in DME at 140 °C for 4 h gives a variety of (enantiopure) trans-cyclopropyl sulfones with high diastereoselectivity.
Nucleophilic Carbenes Derived from Dichloromethane
作者:Mingxin Liu、Nguyen Le、Christopher Uyeda
DOI:10.1002/anie.202308913
日期:2023.10.16
Nickel catalysts promote cyclopropanation reactions of electron-deficient alkenesusing dichloromethane as a methylene source. An asymmetric variant using a chiral pyridine-bis(oxazoline) ligand provides access to pharmaceutically relevant 2-aryl cyclopropyl carboxylates in highly enantioenriched form. The proposed mechanism involves the formation of a nucleophilic nickel carbene that reacts by a
Synthesis of substituted tetrahydrofurans via intermolecular reactions of γ-chlorocarbanions of 3-substituted 3-chloro-propylphenyl sulfones with aldehydes
Carbanions of 3-substituted-3-chloropropyl phenyl sulfones add to carbonyl groups of aldehydes to produce aldol type adducts that undergo 1,5-intramolecular substitution giving 2,3,5-trisubstituted tetrahydrofurans. The effect of substituents in the 3-position of these sulfones on the relative rates of 1,3-intramolecular substitution of the corresponding gamma-chlorocarbanions and their intramolecular addition are disclosed. (C) 2010 Elsevier Ltd. All rights reserved.