A procedure for the enantioselective synthesis of α-substituted glutamates and pyroglutamates via a cyclopropenimine-catalyzed Michael addition of amino ester imines is described. Enantioselectivities of up to 94% have been achieved, and a variety of functional groups were found to be compatible. The impact of the catalyst structure and imine substitution is discussed. Compared to other methods, this protocol allows for a broader and more enantioselective access to pyroglutamate derivatives.

中文翻译：

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通过对映选择性环丙烯亚胺催化氨基酯亚胺的迈克尔加成，对映体富集的α-取代谷氨酸盐/焦谷氨酸盐

描述了通过环丙烯亚胺催化的氨基酯亚胺的迈克尔加成对α-取代的谷氨酸盐和焦谷氨酸盐进行对映选择性合成的过程。已实现高达 94% 的对映选择性，并且发现多种官能团是相容的。讨论了催化剂结构和亚胺取代的影响。与其他方法相比，该协议允许对焦谷氨酸衍生物进行更广泛和更具对映选择性的访问。