into an epoxide was developed using an opticallyactive ketoiminatocobalt(II) complex as a chiral Lewis acid. In the presence of a catalytic amount of the cobalt complex and amine base, enantioselective CO 2 fixation with an epoxide proceeded with kineticresolution to afford the corresponding carbonate along with unreacted epoxide, both of which were opticallyactive. To improve their enantioselectivities
使用光学活性的酮亚氨基钴 (II) 配合物作为手性路易斯酸开发了 CO 2 对映选择性化学固定到环氧化物中。在催化量的钴络合物和胺碱的存在下,与环氧化物的对映选择性 CO 2 固定进行动力学拆分,得到相应的碳酸盐和未反应的环氧化物,两者都是光学活性的。为了提高它们的对映选择性,研究了钴配合物和胺碱的配体结构。因此,优化的催化体系成功地应用于各种环氧化物,以获得相应的光学活性环状碳酸酯,并以良好的对映选择性回收环氧化物。
Chiral Macrocyclic Organocatalysts for Kinetic Resolution of Disubstituted Epoxides with Carbon Dioxide
Among chiral macrocycles 1 synthesized, 1m with the 3,5-bis(trifluoromethyl)phenylethynyl group was the best organocatalyst for the enantioselective synthesis of cyclic carbonates from disubstituted or monosubstituted epoxides and CO2. The X-ray crystal structure of 1m revealed a well-defined chiral cavity with multiple hydrogen-bonding sites that is suitable for the enantioselective activation of