第一个利用酰亚胺自由基的催化策略已经开发出来。这种方法可以通过光催化还原烯丙醇的肟酰亚胺酯来实现烯丙醇的烯烃双官能化。随后的亚氨酸酯自由基经历连续的分子内和分子间反应,通过三种不同的自由基机制提供(i)氢胺化、(ii)氨基烷基化或(iii)氨基芳基化。介绍了这种亚胺酯自由基反应催化方法的广泛范围和实用性,以及与其他 N 中心自由基和互补的闭壳亚胺酯途径的比较。
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
selected cyclopropanes as model substrates since they present a relatively weak σ-bond. Herein, we describe an iridium-catalyzed hydroboration of cyclopropanes, resulting in β-methyl alkylboronates. These unusually branched boronates can be derivatized by oxidation or cross-coupling chemistry, accessing "designer" products that are desired by practitioners of natural product synthesis and medicinal chemistry
Transition metal and base free synthesis of 2-aryl-2-oxazolines from aldehydes and β-amino alcohols catalysed by potassium iodide
作者:C. Uma Maheswari、G. Sathish Kumar、M. Venkateshwar
DOI:10.1039/c4ra08578g
日期:——
Synthesis of 2-aryl-2-oxazolines from β-amino alcohols and aldehydes was achieved in good to excellent yield by employing a potassium iodide (KI)–tert-butyl hydroperoxide (TBHP) catalytic system.
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。
Rhodium(III)‐Catalyzed Synthesis of
<i>N</i>
‐(2‐Acetoxyalkyl)isoquinolones from Oxazolines and Alkynes through C−N Bond Formation and Ring‐Opening
作者:Zi Yang、Lianghua Jie、Zhenyu Yao、Zhimin Yang、Xiuling Cui
DOI:10.1002/adsc.201801217
日期:2019.1.11
An atom‐economic approach for the synthesis of N‐(2‐acetoxyalkyl)isoquinolones from oxazolines and alkynes through rhodium(III)‐catalyzed auto‐tandem reactions involving C−Hbond functionalization/C−N bond formation/ring opening/nucleophilic substitution is described. This protocol features high regioselectivity, tolerance of various functional groups, and retention of absolute configuration of chirality