A new class of easily available and readily tunable proline based chiral organocatalysts was found to efficiently catalyse an unprecedented highly enantioselective asymmetric Darzens reaction of α-chloroketones and substituted α-chloroketones with various aldehydes, which directly produces optically active di- and tri-substituted chiral epoxides with higher product yields (up to 97%) and excellent ee's (up to 99%) under mild reaction conditions.

中文翻译：

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脯氨酸基高效有机催化剂催化的高对映选择性不对称Darzens反应，用于合成二取代和三取代的环氧化物

已发现一类新的易于获得且易于调节的脯氨酸基手性有机催化剂，可有效催化前所未有的高度对映选择性的α-氯代酮和取代的α-氯代酮与各种醛的不对称Darzens反应，可直接产生光学活性的二取代和三取代的手性在温和的反应条件下，环氧化物具有较高的产品收率（高达97％）和优异的ee（高达99％）。