Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China.
Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China.
Angew Chem Int Ed Engl. 2023 May 15;62(21):e202302638. doi: 10.1002/anie.202302638. Epub 2023 Apr 18.
Herein we reported a transition metal-free deborylative cyclization strategy, based on which two routes have been developed, generating racemic and enantioenriched cyclopropylboronates. The cyclization of geminal-bis(boronates) bearing a leaving group was highly diastereoselective, tolerating a few functional groups and applicable to heterocycles. When optically active epoxides were used as the starting materials, enantioenriched cyclopropylboronates could be efficiently prepared with >99 % stereospecificity. Mechanistic studies showed that the leaving group at the γ-position played a crucial role and significantly promoted the activation of the gem-diboron moiety.
在此，我们报告了一种无过渡金属的去硼环化策略，在此基础上开发了两种路线，生成了外消旋和对映富集的环丙基硼酸酯。带有离去基团的偕二（硼酸酯）的环化具有高度的非对映选择性，可耐受一些官能团，并适用于杂环。当使用光学活性环氧化物作为起始原料时，可以高效地制备对映富集的环丙基硼酸酯，立体选择性大于 99%。机理研究表明，γ-位的离去基团起着关键作用，并显著促进了偕二硼部分的活化。
