Highly Enantioselective Intermolecular Cyclopropanation Catalyzed by Dirhodium(II) Tetrakis[3(<i>S</i>)-phthalimido-2-piperidinonate]: Solvent Dependency of the Enantioselection
作者:Shinji Kitagaki、Hideo Matsuda、Nobuhide Watanabe、Shun-ichi Hashimoto
DOI:10.1055/s-1997-994
日期:1997.10
The enantioselectivity in cyclopropanations catalyzed by dirhodium(II) tetrakis[3(S)-phthalimido-2-piperidinonate] has been found to be substantially improved by employing ether as the rarely used solvent. Cyclopropanations of styrenes or 1,1-disubstituted alkenes with 2,4-dimethyl-3-pentyl diazoacetate in ether are promoted by this catalyst to afford the corresponding cyclopropane products in the highest levels of enantioselectivity (up to 98% ee) reported to date for the dirhodium(II)-catalyzed intermolecular cyclopropanation reactions.
由二铑(II)四[3(S)-邻苯二甲酰胺-2-哌啶酸酯]催化的环丙烷化反应中的对映选择性已被发现通过使用作为罕见溶剂的醚显著改善。该催化剂促进了苯乙烯或1,1-二取代烯烃与2,4-二甲基-3-戊基二氮酰乙酸酯在醚中进行的环丙烷化反应,产生了相应的环丙烷产品,报告的对映选择性达到最高水平(高达98% ee),这是迄今为止二铑(II)催化的分子间环丙烷化反应中所取得的最高记录。