Bal Ankita, Maiti Saikat, Mal Prasenjit
School of Chemical Sciences , National Institute of Science Education and Research (NISER), HBNI, Bhubaneswar , PO Bhimpur-Padanpur, Via Jatni, District Khurda , Odisha 752050 , India.
J Org Chem. 2018 Sep 21;83(18):11278-11287. doi: 10.1021/acs.joc.8b01857. Epub 2018 Aug 31.
Here we report a metal-free C-N coupling reaction for carbazole synthesis by distal (- meta) C-H bond functionalization. Nitrenium ion, a potential synthetic intermediate, was generated in situ from reactions of iodine(III) reagents and biarylsulfonanilides. Following, nitrenium ions were used for intramolecular dehydrogenative C-N coupling reactions via 1,2-alkyl (methyl or ethyl) migration by the expense of C-H bond functionalization at the distal position toward synthesis of 1,2,4-trialkyl-substituted carbazoles. The iodine(III) condition was either maintained by using a stoichiometric amount of phenyliodine diacetate (PIDA) or in-situ generated from iodobenzene (PhI)- meta-chloroperbenzoic acid ( mCPBA) combination.
在此，我们报道了一种通过远端（间位）C-H键官能化合成咔唑的无金属C-N偶联反应。氮鎓离子是一种潜在的合成中间体，由碘（III）试剂与联芳基磺酰苯胺反应原位生成。随后，氮鎓离子通过1,2-烷基（甲基或乙基）迁移用于分子内脱氢C-N偶联反应，以消耗远端位置的C-H键官能化来合成1,2,4-三烷基取代的咔唑。碘（III）条件可通过使用化学计量的二乙酸碘苯（PIDA）来维持，或由碘苯（PhI）-间氯过苯甲酸（mCPBA）组合原位生成。
