A convenient and efficient method for the synthesis of highly functionalized cyclopropa[c]coumarin derivatives in good to excellent yields via cascade Michael-alkylation process of 3-substituted coumarins and 2-bromomalonate was developed. Preliminary results indicated that using a chiral PTC strategy, the desired cyclopropanation product could be obtained in up to 41% ee.

中文翻译：

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通过3-氰基香豆素与2-溴丙二酸酯的级联迈克尔-烷基化工艺构建环丙香豆素[ c ]香豆素

开发了一种方便高效的方法，可通过3-取代香豆素和2-溴丙二酸酯的级联迈克尔-烷基化反应合成高官能度的环丙[ c ]香豆素衍生物，产率高至优异。初步结果表明，使用手性PTC策略，可以以不超过41％ee的比例获得所需的环丙烷化产物。