Department of Chemistry, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China.
Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China.
J Org Chem. 2021 Jan 1;86(1):235-253. doi: 10.1021/acs.joc.0c02047. Epub 2020 Dec 18.
Reported here is the room-temperature metal-free iodoarene-catalyzed oxyamination of unactivated alkenes. In this process, the alkenes are difunctionalized by the oxygen atom of the amide group and the nitrogen in an exogenous HNTs molecule. This mild and open-air reaction provided an efficient synthesis to -bistosyl-substituted 5-imino-2-tetrahydrofuranyl methanamine derivatives, which are important motifs in drug development and biological studies. Mechanistic study based on experiments and density functional theory calculations showed that this transformation proceeds via activation of the substrate alkene by an generated cationic iodonium(III) intermediate, which is subsequently attacked by an oxygen atom (instead of nitrogen) of amides to form a five-membered ring intermediate. Finally, this intermediate undergoes an S2 reaction by NTs as the nucleophile to give the oxygen and nitrogen difunctionalized 5-imino-2-tetrahydrofuranyl methanamine product. An asymmetric variant of the present alkene oxyamination using chiral iodoarenes as catalysts also gave promising results for some of the substrates.
本文报道了室温无金属碘代芳烃催化的未活化烯烃的氧化氨化反应。在该过程中,酰胺基团的氧原子和外源 HNTs 分子中的氮原子对烯烃进行双官能化。这种温和的、在空气中进行的反应为 -双取代 -5-亚氨基-2-四氢呋喃甲胺衍生物提供了一种有效的合成方法,该衍生物是药物开发和生物研究中的重要结构单元。基于实验和密度泛函理论计算的机理研究表明,该转化是通过生成的阳离子碘𬭩(III)中间体对底物烯烃的活化来进行的,随后该中间体被酰胺的氧原子(而不是氮原子)进攻,形成五元环中间体。最后,这个中间体通过 NTs 作为亲核试剂进行 S2 反应,得到氧和氮双官能化的 5-亚氨基-2-四氢呋喃甲胺产物。使用手性碘芳烃作为催化剂的不对称变体的本烯烃氧化氨化反应,对一些底物也给出了有前景的结果。