New chiral crown ethers derived from camphor and their application to asymmetric Michael addition. First attempts to rationalize enantioselection by AM1 and AMBER calculations
作者:Ernesto Brunet、Ana M. Poveda、Dolores Rabasco、Enrique Oreja、Luis M. Font、Manohar Singh Batra、Juan C. Rodriguez-Ubis
DOI:10.1016/s0957-4166(00)86246-1
日期:1994.5
optically active crown ethers derived from (1R)-(+)-camphor is described. The mechanism of their catalytic effect upon the Michael addition of phenylacetate to acrylate is discussed in terms of kinetic vs. thermodynamic control in the formation of the catalytic ion-pair complexes. The relative basicity of the complexes formed between the alkaline metals and the unprotonated chiral crown ethers plays an important
描述了衍生自(1 R)-(+)-樟脑的新型旋光冠醚的合成。从动力学对动力学的角度讨论了它们在苯乙酸迈克尔加成到丙烯酸酯上的催化效应机理。催化离子对络合物形成过程中的热力学控制。碱金属和未质子化的手性冠醚之间形成的配合物的相对碱性在立体化学结果中起重要作用。AMBER和AM1计算支持在动力学控制下进行获得最佳ee(83%)的反应。