Chiral octahedral complexes of Co(<scp>iii</scp>) as catalysts for asymmetric epoxidation of chalcones under phase transfer conditions
作者:Vladimir A. Larionov、Elina P. Markelova、Alexander F. Smol'yakov、Tat'yana F. Savel'yeva、Victor I. Maleev、Yuri N. Belokon
DOI:10.1039/c5ra11760g
日期:——
Stereochemically inert and positively charged chiralcomplexes of Co(III) were shown to catalyze the asymmetric epoxidation of chalcones with H2O2 under phase transfer conditions. The reaction products had enantiomeric purities of up to 55%. It was also shown that complex 1a I− catalyzed the coupling reaction of a resulting epoxide with CO2 (conversion 72%).
在相转移条件下,Co(III)的立体化学惰性和带正电荷的手性配合物可催化查耳酮与H 2 O 2的不对称环氧化。反应产物的对映体纯度高达55%。它也表明,复杂1A我-催化的与CO所得环氧化物的偶联反应2(转化72%)。
Scoping the triphasic/PTC conditions for the Juliá–Colonna epoxidation reaction
作者:Thomas Geller、Christa M. Krüger、H.-Christian Militzer
DOI:10.1016/j.tetlet.2004.04.189
日期:2004.6
A new, highly efficient procedure for the Juliá–Colonnaepoxidation is reported. Based on the original triphasic protocol it is shown that the co-catalysis of the reaction with phase transfer catalysts results in a dramatic increase of reactivity and sometimes also in a higher enantiomeric excess of product. The required amount of polyamino acid can be significantly reduced under the new conditions
Development of the juliá asymmetric epoxidation reaction. Part 1. Application of the oxidation to enones other than chalcones
作者:M. Elena Lasterra-Sánchez、Ulfried Felfer、Patrick Mayon、Stanley M. Roberts、Steven R. Thornton、Christine J. Todd
DOI:10.1039/p19960000343
日期:——
Asymmetric epoxidation of a variety of enones 3, 6, 8, 10, 12, 14, 16, 18, 21, 22, 26, 28-30 and 36 gives the corresponding oxiranes in good to excellent yield and optical purity, The oxidation medium consists of basic peroxide or sodium perborate or sodium percarbonate or tert-butylhydroperoxide and the preferred catalyst is polyleucine, conveniently prepared from the N-carboxyanhydride using 1,3-diaminopropane.