Site‐Specific C(sp<sup>3</sup>)–H Aminations of Imidates and Amidines Enabled by Covalently Tethered Distonic Radical Anions
作者:Rong Zhao、Kang Fu、Yuanding Fang、Jia Zhou、Lei Shi
DOI:10.1002/anie.202008806
日期:2020.11.9
utilization of N‐centered radicals to synthesize nitrogen‐containing compounds has attracted considerable attention recently, due to their powerful reactivities and the concomitant construction of C−N bonds. However, the generation and control of N‐centered radicals remain particularly challenging. We report a tethering strategy using SOMO‐HOMO‐converted distonic radical anions for the site‐specific
Radical-mediated intramolecular β-C(sp<sup>3</sup>)–H amidation of alkylimidates: facile synthesis of 1,2-amino alcohols
作者:Xue-Qing Mou、Xiang-Yu Chen、Gong Chen、Gang He
DOI:10.1039/c7cc08897c
日期:——
A new radical-mediated intramolecular β-C(sp3)–H amidation reaction of O-alkyl trichloro- or arylimidates is reported. Various oxazolines were efficiently prepared from easily accessible alcohol starting materials. The trichloro-oxazoline products can be hydrolyzed under mild conditions to give valuable 1,2-amino alcohols. This amidation reaction exhibits a broad substrate scope and good functional
Access to Benzoxazepines and Fully Substituted Indoles via HDDA Coupling
作者:Xiaojie Zheng、Baohua Liu、Feihu Yang、Qiong Hu、Liangliang Yao、Yimin Hu
DOI:10.1021/acs.orglett.9b04499
日期:2020.2.7
The HDDA-derived benzyne intermediate was captured by oxazolines based on the addition reaction of benzyne to the C═N double bond. Benzoxazepine derivatives, fused benzoxazepine derivatives, and fully substituted indoles are synthesized in one step. The reaction does not require any catalyst or additives. Possible reaction mechanisms are presented.
Directed β C–H Amination of Alcohols via Radical Relay Chaperones
作者:Ethan A. Wappes、Kohki M. Nakafuku、David A. Nagib
DOI:10.1021/jacs.7b05214
日期:2017.8.2
for β C-H amination of alcohols has been developed. This approach employs a radical relay chaperone, which serves as a traceless director that facilitates selective C-H functionalization via 1,5-hydrogen atom transfer (HAT) and enables net incorporation of ammonia at the β carbon of alcohols. The chaperones presented herein enable direct access to imidate radicals, allowing their first use for H atom
已经开发了一种自由基介导的醇类 β CH 胺化策略。该方法采用自由基中继伴侣,作为无痕导向剂,通过 1,5-氢原子转移 (HAT) 促进选择性 CH 官能化,并使氨在醇的 β 碳上净结合。本文介绍的分子伴侣能够直接访问亚胺酸酯自由基,从而使其首次用于 H 原子提取。简化的方案能够将醇快速转化为它们的 β-氨基类似物(通过将醇原位转化为亚胺酸酯、定向 CH 胺化和水解为 NH2)。机械实验表明 HAT 是限速的,而分子内胺化是产物和立体决定。
Photochemical Transformation of <i>O</i>
-(β-Arylethyl) Arylimidates into 2,4-Diaryl-5-iodoxazoles with 1,3-Diiodo-5,5-dimethylhydantoin
作者:Aya Saito、Hideo Togo
DOI:10.1002/ejoc.202000383
日期:2020.6.16
2,4‐Diaryl‐5‐iodoxazoles could be obtained by the treatment of O ‐(β‐arylethyl) arylimidates with 1,3‐diiodo‐5,5‐dimethylhydantoin (DIH) under irradiation with a tungsten lamp. This reaction proceeds through multiple stets, i.e., formation of N ‐iodoimidate, iminyl radical, 1,5‐H shift, 5‐exo‐tet cyclization to oxazoline, oxidation to oxazole, and iodination to 5‐iodoxazole.