Rhodium-Catalyzed Ring Expansion of Azetidines via Domino Conjugate Addition/N-Directed α-C(sp<sup>3</sup>)–H Activation
作者:Ling-Zhi Sun、Xuan Yang、Nan-Nan Li、Meng Li、Qin Ouyang、Jian-Bo Xie
DOI:10.1021/acs.orglett.2c00056
日期:2022.3.18
4-aryl-4,5-dihydropyrrole-3-carboxylates is developed, with a rhodium-catalyzed ring expansion strategy from readily available 2-(azetidin-3-ylidene) acetates and aryl boronic acids. Mechanistic investigations suggest a novel domino “conjugate addition/N-directed α-C(sp3)–H activation” process. The asymmetric catalytic synthesis of the 4-aryl-4,5-dihydropyrrole-3-carboxylate is realized by using QuinoxP* (91–97%
开发了一种简便的 4-aryl-4,5-dihydropyrrole-3-carboxylates 合成方法,该方法采用铑催化的扩环策略,由容易获得的 2-(azetidin-3-ylidene) 乙酸酯和芳基硼酸组成。机理研究表明了一种新的多米诺骨牌“共轭加成/N 向 α-C(sp 3 )-H 活化”过程。使用 QuinoxP* (91–97% ee) 实现了 4-aryl-4,5-dihydropyrrole-3-carboxylate 的不对称催化合成。该协议的合成效用通过合成具有优异非对映选择性的 3,4-二取代或 2,3,4-三取代吡咯烷来证明。