Asymmetric Inter- and Intramolecular Cyclopropanation of Alkenes Catalyzed by Chiral Ruthenium Porphyrins. Synthesis and Crystal Structure of a Chiral Metalloporphyrin Carbene Complex
作者:Chi-Ming Che、Jie-Sheng Huang、Fu-Wa Lee、Yan Li、Tat-Shing Lai、Hoi-Lun Kwong、Pang-Fei Teng、Wing-Sze Lee、Wai-Cheung Lo、Shie-Ming Peng、Zhong-Yuan Zhou
DOI:10.1021/ja001416f
日期:2001.5.1
to 36 and extremely high catalyst turnovers of up to 1.1 x 10(4). Examination of the effects of temperature, diazoacetate, solvent, and substituent in the intermolecular cyclopropanation reveals that (i) both enantioselectivity and trans selectivity increase with decreasing temperature, (ii) sterically encumbered diazoacetates N2CHCO2R, such as R = Bu(t), and donor solvents, such as diethyl ether and
钌卟啉催化重氮乙酸酯对末端烯烃不对称分子间环丙烷化的广泛研究 [Ru(P*)(CO)(EtOH)] (1, H2P = 5,10,15,20-tetrakis[(1S,4R,5R, 8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracene-9-yl]porphyrin) 和催化剂 1 在烯丙或不对称分子内环丙烷化中的应用描述了高烯丙基重氮乙酸酯。苯乙烯及其衍生物与重氮乙酸乙酯的分子间环丙烷化得到相应的环丙酯,ee 高达 98%,具有高达 36 的高反/顺比和高达 1.1 x 10(4) 的极高催化剂周转率。检查温度、重氮乙酸盐、溶剂、分子间环丙烷化中的取代基表明 (i) 对映选择性和反式选择性都随着温度的降低而增加,(ii) 空间位阻重氮乙酸盐 N2CHCO2R,例如 R = Bu(t),以及供体溶剂,例如乙醚和四氢呋喃,是有利于反式选择性,和