Organocatalytic enantioselective β-functionalization of aldehydes by oxidation of enamines and their application in cascade reactions
Organocatalytic enantioselective β-functionalization of aldehydes by oxidation of enamines and their application in cascade reactions
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DOI：
10.1038/ncomms1214
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发表时间：
2011-03-01
影响因子：
16.6
通讯作者：
Wang, Wei
中科院分区：
文献类型：
--
作者：
Zhang, Shi-Lei;Xie, He-Xin;Wang, Wei
在许多有机过程的背景下，已经广泛地研究了涉及亚胺离子到烯胺的转化的离子催化。然而，涉及将烯胺转化为亚胺鎓物质的该过程的逆过程尚未实现。在这里，我们描述了一种新的转换-'氧化烯胺催化'-其中发生直接氧化的烯胺产生的亚胺物种。我们表明，使用邻碘酰苯甲酸作为氧化剂的存在下的仲胺催化剂作为有效的系统，促进快速转化烯胺亚胺离子。该方法的制备能力已在简单醛的直接不对称β-官能化的背景下得到证实。此外，已经开发了多种对映选择性级联转化，包括三重和四重级联，用于从简单醛开始“一锅”合成多功能手性结构单元和结构框架。
Iminium catalysis, involving the transformation of iminium ions to enamines, has been extensively studied in the context of a number of organic processes. However, the reverse of this process involving conversion of enamines to iminium species has not been realized. Here, we describe a new transformation-'oxidative enamine catalysis'-in which direct oxidation of an enamine occurs to generate an iminium species. We show that the use of o-iodoxybenzoic acid as an oxidant in the presence of a secondary amine catalyst serves as effective system for promoting rapid conversion of enamines to iminium ions. The preparative power of this process has been demonstrated in the context of direct asymmetric beta-functionalization of simple aldehydes. Moreover, a variety of enantioselective cascade transformations, including triple and quadruple cascades, have been developed for the 'one-pot' synthesis of versatile chiral building blocks and structural frameworks starting with simple aldehydes.