Sterically crowded cyclopropanation catalysts. Syn-selectivity using rhodium(III)porphyrins
作者:H.J. Callot、F. Metz、C. Piechocki
DOI:10.1016/0040-4020(82)87014-2
日期:1982.1
Rhodium(III)porphyrins catalyze the decomposition of ethyl diazoacetate and the transfer of ethoxy-carbonylcarbene to alkenes to form cyclopropanes in moderate to high yields. When compared with other catalysts a large syn-selectivity was observed on reaction with cis-alkenes. This selectivity increased with the size of the substituents, and suggested a preferential direction of approach of the alkene
铑(III)卟啉催化重氮乙基乙酸乙酯的分解以及乙氧基羰基碳烯向烯烃的转移,以中等至高收率形成环丙烷。当与其他催化剂相比时,在与顺式烯烃的反应中观察到大的顺选择性。该选择性随取代基的大小而增加,并暗示了烯烃向铑-卡宾络合物的优先接近方向。