Catalytic asymmetric [3+2] cycloaddition of aromatic aldehydes with oxiranes by C–C bond cleavage of epoxides: highly efficient synthesis of chiral 1,3-dioxolanes
A novel and efficient N,N'-dioxide-Gd(III) complex was developed for the highly diastereo- and enantioselective [3+2] cycloaddition of aryl oxiranyl diketones and aldehydes via C-C bondcleavage of oxiranes. The corresponding chiral 1,3-dioxolanes were obtained in excellent yields (up to 99%) with high diastereoselectivities (>95 : 5 dr) and enantioselectivities (up to 91% ee). Moreover, a possible
Highly regioselective Lewis acid-catalyzed [3+2] cycloaddition of alkynes with donor–acceptor oxiranes by selective carbon–carbon bond cleavage of epoxides
作者:Renrong Liu、Mei Zhang、Junliang Zhang
DOI:10.1039/c1cc15669a
日期:——
A novel, efficient, highly regioselective Sc(OTf)3-catalyzed [3+2] cycloaddition of electron-rich alkynes with donorâacceptor oxiranes via highly chemoselective CâC bond cleavage under mild conditions was developed.
Lewis Acid Catalyzed Carbon−Carbon Bond Cleavage of Aryl Oxiranyl Diketones: Synthesis of <i>cis</i>-2,5-Disubstituted 1,3-Dioxolanes
作者:Zuliang Chen、Lai Wei、Junliang Zhang
DOI:10.1021/ol2000292
日期:2011.3.4
Carbonylylide is one of the most important intermediates which can undergo a series of 1,3-dipolar cycloaddition reactions. The C−C heterolysis of oxirane is believed to be the most atom-economic and straightforward way to generate carbonylylide. However, this chemistry was only achieved under photochemical and thermal conditions in past years. In this work, the one-step diastereoselective synthesis