of tertiary and secondary benzylic C(sp3)-H, aliphatic C(sp3)-H, and drug-molecules-based C(sp3)-H bonds containing in substrates are well tolerated under our protocol. The simultaneous gram-scale synthesis and the ease of transformation of azide to amine collec-tively advocate for the potential application in the preparative syn-thesis. Good reactivity of tertiary benzylic C(sp3)-H bond and se-lectivity
Novel Synthesis of 3-Substituted 2,3-Dihydrobenzofurans via <i>ortho</i>-Quinone Methide Intermediates Generated <i>in Situ</i>
作者:Abdul kadar Shaikh、George Varvounis
DOI:10.1021/ol500290e
日期:2014.3.7
A new method is presented for the regioselective one-pot synthesis of 3-substituted 2,3-dihydrobenzofurans from 2-bromo-1-2-[(triisopropylsilyl)oxy]phenyl}ethyl nitrate by fluoride-induced desilylation leading to o-quinone methide generation, Michael addition of different C, N, O, and S nucleophiles, and intramolecular 5-exo-tet elimination of a bromide anion. The method has potential synthetic applications
作者:Tjark H. Meyer、Ramesh C. Samanta、Antonio Del Vecchio、Lutz Ackermann
DOI:10.1039/d0sc05924b
日期:——
Manganaelectro-catalyzed azidation of otherwise inert C(sp3)–H bonds was accomplished using most user-friendly sodium azide as the nitrogen-source. The operationally simple, resource-economic C–H azidation strategy was characterized by mild reaction conditions, no directing group, traceless electrons as the sole redox-reagent, Earth-abundant manganese as the catalyst, high functional-group compatibility
使用大多数用户友好的叠氮化钠作为氮源,完成了锰电催化的惰性 C(sp 3 )–H 键的叠氮化。操作简单、资源经济的C-H叠氮化策略具有反应条件温和、无导向基团、无痕电子作为唯一氧化还原试剂、地球丰富的锰作为催化剂、高官能团相容性和高化学选择性等特点。生物活性化合物的后期叠氮化阶段。通过实验、分光光度法和循环伏安法进行的详细机理研究为金属催化脂肪族自由基的形成以及随后在锰( III / IV )流形内的叠氮基自由基转移提供了强有力的支持。
Kinetic Resolution of Cyclic Secondary Azides, Using an Enantioselective Copper-Catalyzed Azide–Alkyne Cycloaddition
作者:Juliana R. Alexander、Amy A. Ott、En-Chih Liu、Joseph J. Topczewski
DOI:10.1021/acs.orglett.9b01556
日期:2019.6.7
An enantioselectivecopper-catalyzedazide–alkynecycloaddition (E-CuAAC) is reported by kinetic resolution. Chiral triazoles were isolated in high yield with limiting alkyne (up to 97:3 enantiomeric ratio (er)). A range of substrates were tolerated (>30 examples), and the reaction was scaled to >1 g. The er of a triazole product could be enhanced by recrystallization and the recovered scalemic azide