Cu(OAc)2, and dioxygen in molten tetrabutylammonium acetate (TBAA) promotes an unusual cyclopropanation reaction between arylmethylketones and styrenes. The process is a dehydrogenative cyclizing coupling that involves a twofold CH activation at the α‐position of the ketone. The substrate scope highlights the flexibility of the catalyst; a reaction mechanism is also proposed.
An unprecedented triplecatalytic, general ring-opening cyanationreaction of cyclopropyl ketones for the construction of γ-cyanoketones is described. The key is to merge photoredox catalysis with Lewis acid catalysis and copper catalysis to enable the selective cleavage of the carbon–carbonbonds and the selective coupling of the generated radical and cyanide anion.
Intermolecular asymmetric cyclopropanation with diazoketones catalyzed by chiral ruthenium porphyrins
作者:Irène Nicolas、Paul Le Maux、Gérard Simonneaux
DOI:10.1016/j.tetlet.2008.01.129
日期:2008.3
The asymmetric addition of diazoacetophenone to styrene derivatives to give optically active cyclopropyl ketones (ee up to 86%) was carried out by using chiral ruthenium porphyrins as homogeneous catalysts.
A highly efficient approach to (Z)-conjugated enynes has been developed by utilizing an Au(III)-catalyzed ring opening reaction of 1-cyclopropyl-2-yn-1-ols with nucleophiles under mild conditions; the method is valuable due to the excellent yield and high regio- and stereoselectivity.
AlCl3-mediated nucleophilic ring-opening reactions of indoline-2-thiones with various acyl cyclopropanes, bi-cyclopropanes and spirocyclic cyclopropanes were investigated. A series of ketones functionalized with indolylthio groups were synthesized in yields ranging from moderate to good. Moreover, chemical transformations of 4-indolylthio butan-1-ones to dihydro-2H-thiepino[2,3-b]indoles and sulfone
研究了AlCl 3介导的二氢吲哚-2-硫酮与各种酰基环丙烷、双环丙烷和螺环环丙烷的亲核开环反应。合成了一系列用吲哚硫基官能化的酮,产率从中等到良好。此外,将4-吲哚硫基丁-1-酮化学转化为二氢-2H-噻吩并[2,3- b ]吲哚和砜,以进一步扩大合成实用性和结构复杂性。