Copper-Catalyzed Modular Access to N-Fused Polycyclic Indoles and 5-Aroyl-pyrrol-2-ones via Intramolecular N-H/C-H Annulation with Alkynes:Scope and Mechanism Probes

• 作者: Yan-Hua Liu Hong Song Chi Zhang Yue-Jin Liu Bing-Feng Shi
• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2020,（12）
• 所属期刊栏目: Concise Reports
• 页码范围: 1545-1552
• 页数: 8页
• 语种: 英文
• DOI: 10.1002/cjoc.202000246

摘要

Copper-catalyzed intramolecular N—H/C—H annulation with alkynes has been developed.A variety of densely functionalized heterocycles,such as pyrrolo[1,2-a]indoles,indolo[1,2-c]quinazolin-2-ones,oxazolo[3,4-a]indoles,and imidazo[1,5-a]indoles,were synthesized in an atom-and step-economical manner,owing to the high modularized feature of aniline moiety,the linker moiety,as well as the alkyne moiety.By simply changing the oxidant from di-tert-butyl peroxide(DTBP)to 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO),the reaction could readily be transformed to the aminooxygenation pathway,which grabs one oxygen atom from the TEMPO to generate 5-aroyl-pyrrol-2-ones.Mechanistic experi-ments indicate that vinyl radical is involved in this reaction and an amidyl-radical-initiated radical cascade might be responsible for this transformation.