Enantioselective Epoxidation of Electron-Deficient Alkenes Catalyzed by Manganese Complexes with Chiral N<sub>4</sub>
Ligands Derived from Rigid Chiral Diamines
作者:Xiangning Chen、Bao Gao、Yijin Su、Hanmin Huang
DOI:10.1002/adsc.201700541
日期:2017.8.7
series of tetradentate sp2N/sp3N hybrid chiral N4 ligands derived from rigid chiral diamines were synthesized, which enabled the first manganese-catalyzed enantioselective epoxidation of electron-deficientalkenes with hydrogenperoxide (H2O2) as an oxidant. The reaction furnishes enantiomerically pure epoxy amides, epoxy ketones as well as epoxy esters in good yields and excellent enantioselectivities
合成了一系列衍生自刚性手性二胺的四齿sp 2 N / sp 3 N杂合手性N 4配体,这使锰能够以过氧化氢(H 2 O 2)为氧化剂,首次对缺电子烯烃进行对映选择性环氧化。。该反应以较低的催化剂负载量提供了对映体纯的环氧酰胺,环氧酮以及环氧酯,具有良好的收率和优异的对映选择性(最高99.9%ee)。对结构-活性关系的初步研究表明,保持sp 3的相对较低的供电子能力N和N 2配体的sp 2 N的相对较高的供电子能力有利于获得更高的活性和选择性,从而为我们理解H 2 O 2的环氧化提供了新的视角。