Dethe Dattatraya H, Singh Prabhakar, Joshi Asha, Biswas Proshanta
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
J Org Chem. 2024 Sep 20;89(18):13167-13178. doi: 10.1021/acs.joc.4c01289. Epub 2024 Sep 11.
Until now, a myriad of effective approaches have emerged for the functionalization of -heteroaryl C-H bonds. In contrast, dearomatization and construction of fused heterocycles from activated heteroarenes is still a subject to explore. In this work, we present a refined approach for both dearomatization of -heteroarenes and the synthesis of fused heterocycles from activated heteroarenes ruthenium catalysis using paraformaldehyde along with additive and base. Notably, quinolinium salts with a hydrogen at the C-4 position yield a methoxymethyl-substituted fused cyclic product through the Thorpe Ingold effect. An innovative aspect of this research is the dual functionality of paraformaldehyde as both a hydride donor and electrophile, utilizing readily available feedstock chemicals. A broad range of electron withdrawing and donating substituents was tolerable under standardized reaction conditions.
到目前为止，已经出现了无数种用于-杂芳基C-H键官能化的有效方法。相比之下，从活化的杂芳烃进行去芳构化和构建稠合杂环仍然是一个有待探索的课题。在这项工作中，我们提出了一种改进的方法，用于-杂芳烃的去芳构化以及从活化的杂芳烃通过钌催化、多聚甲醛以及添加剂和碱合成稠合杂环。值得注意的是，在C-4位带有氢的喹啉鎓盐通过索普-英戈尔德效应生成甲氧基甲基取代的稠环产物。这项研究的一个创新点是多聚甲醛作为氢化物供体和亲电试剂的双重功能，利用了容易获得的原料化学品。在标准化反应条件下，各种吸电子和供电子取代基都是可以耐受的。
