Department of Chemistry, Indian Institute of Technology Jodhpur, NH-65 Nagaur Road, Karwar - 342037, Jodhpur District, Rajasthan, India.
Org Biomol Chem. 2019 Jul 14;17(26):6326-6341. doi: 10.1039/c9ob00694j. Epub 2019 Jun 19.
Late stage functionalization (LSF) through direct X-H manipulations (X = C, N) enables synthetic chemists to accelerate the diversification of natural products, agrochemicals and pharmaceuticals allowing rapid access to novel bioactive molecules without resorting to arduous de novo synthesis. LSF does not only allow tapping of the hitherto unexplored chemical space but also renders the synthetic sequence more straightforward, atom economical and cost-effective. In this regard, the recent decade has witnessed the emergence of hypervalent iodine(iii) reagents as a powerful synthetic tool owing to their easy availability, mild reaction conditions, remarkable oxidizing properties and high functional group tolerance. Iodine(iii) reagents have tremendous applications in the regio- and chemo-selective late-stage functionalization of a diverse variety of heterocycles through an exciting range of transformations, such as oxidative amination, cross-dehydrogenative coupling (CDC), fluoroalkylation, azidation, halogenation and oxidation. The present review, classified according to the types of synthetic methods involved, encompasses all these recent developments in the field of transition-metal-free iodine(iii)-catalyzed/mediated direct functionalizations of heterocycles with representative examples and insightful mechanistic discussions.
晚期功能化（LSF）通过直接 X-H 操作（X = C，N），使合成化学家能够加速天然产物、农用化学品和药物的多样化，无需进行艰苦的从头合成，即可快速获得新的生物活性分子。LSF 不仅允许开发迄今为止尚未开发的化学空间，而且使合成序列更加直接、原子经济性和具有成本效益。在这方面，最近十年见证了高价碘（III）试剂作为一种强大的合成工具的出现，这是由于它们易于获得、温和的反应条件、显著的氧化性质和高官能团耐受性。碘（III）试剂在通过一系列令人兴奋的转化（如氧化氨化、交叉脱氢偶联（CDC）、氟烷基化、叠氮化、卤化和氧化）对各种杂环进行区域和化学选择性的晚期功能化方面具有巨大的应用。根据所涉及的合成方法的类型，本综述涵盖了无过渡金属碘（III）催化/介导的杂环直接功能化领域的所有这些最新进展，包括代表性实例和深入的机理讨论。
