Li Xiangqiang, Zeng Hongkun, Lin Lili, Feng Xiaoming
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.
Org Lett. 2021 Apr 16;23(8):2954-2958. doi: 10.1021/acs.orglett.1c00631. Epub 2021 Mar 26.
A highly enantioselective three-component reaction of ynamides with carboxylic acids and 2,2'-diester aziridines has been realized by using a chiral ,'-dioxide/Ho(OTf) complex as a Lewis acid catalyst. The process includes the formation of an α-acyloxyenamide intermediate through the addition of carboxylic acids to ynamides and the following enantioselective nucleophilic addition to -generated azomethine ylides induced by the chiral catalyst. A range of amino acyloxyenamides are delivered in moderate to good yields with good ee values. In addition, a possible catalytic cycle with a transition model is proposed to elucidate the reaction mechanism.
通过使用手性双噁唑啉/三氟甲磺酸钬（Ho(OTf)）配合物作为路易斯酸催化剂，实现了炔酰胺与羧酸和2,2'-二酯氮杂环丙烷的高度对映选择性三组分反应。该过程包括通过羧酸与炔酰胺加成形成α-酰氧基烯酰胺中间体，以及随后在手性催化剂诱导下对生成的甲亚胺叶立德进行对映选择性亲核加成。一系列氨基酰氧基烯酰胺以中等至良好的产率和良好的对映体过量值得到。此外，还提出了一个带有过渡模型的可能催化循环来阐明反应机理。
