Enantioselective dirhodium(II)-catalyzed cyclopropanations with trimethylsilylethyl and trichloroethyl aryldiazoacetates
作者:Solymar Negretti、Carolyn M. Cohen、Jane J. Chang、David M. Guptill、Huw M.L. Davies
DOI:10.1016/j.tet.2015.05.045
日期:2015.9
readily prepared by rhodium-catalyzedcyclopropanation of alkenes with aryldiazoacetates and styryldiazoaceates, in which the ester functionality is either trimethylsilylethyl (TMSE) or trichloroethyl (TCE). By having labile protecting groups on the ester, chiral triarylcyclopropane carboxylate ligands were conveniently prepared. The asymmetric induction during cyclopropanation is dependent on the
The indium-promoted chemoselective deprotection of 2,2,2-trichloroethyl esters containing a benzylic methylene was successfully achieved by employing deuterated solvents. (C) 2010 Elsevier Ltd. All rights reserved.
2,2,2-Trichloroethyl Aryldiazoacetates as Robust Reagents for the Enantioselective C–H Functionalization of Methyl Ethers
作者:David M. Guptill、Huw M. L. Davies
DOI:10.1021/ja5107404
日期:2014.12.24
A new class of reagents is described for C-H functionalization by means of C-H insertion using donor/acceptor-substituted rhodium(II) carbene intermediates. The 2,2,2-trichloroethyl aryl and heteroaryl diazoacetates, together with the dirhodium triarylcyclopropane carboxylate catalyst Rh2(R-BPCP)4, enabled the enantioselective intermolecular C-H functionalization of a range of methyl ethers with high levels of site selectivity and enantioselectivity.
Indium-mediated chemoselective deprotection and demonochlorination of 2,2,2-trichloroethyl esters
作者:Tomoko Mineno、Hisao Kansui、Takehisa Kunieda
DOI:10.1016/j.tetlet.2007.05.099
日期:2007.7
On treatment with indium metal, the 2,2,2-trichloroethyl carboxylates smoothly undergo deprotection to carboxylic acids and reductive demonochlorination to 2,27dichloroethyl esters, sharply depending on their structures. (C) 2007 Elsevier Ltd. All rights reserved.
Metal-Free C–H Functionalization of Alkanes by Aryldiazoacetates
作者:Cecilia Tortoreto、Daniel Rackl、Huw M. L. Davies
DOI:10.1021/acs.orglett.6b03681
日期:2017.2.17
Thermally induced reactions of donor/acceptor diazo compounds generate carbene intermediates capable of C–H functionalization reactions of alkanes. A variety of C–H insertion products were obtained in moderate to good yields and in certain cases with good site selectivity, favoring the functionalization of the more highly substituted C–H bond.