An effective metal-free C-H amination of N-Ts-2-alkenylanilines by using DDQ as an oxidant has been developed to afford a diverse range of substituted indoles. This protocol is operationally simple and robust, obviates the need of expensive transition-metal catalysts, and offers a broad substrate scope. A mechanism involving a radical cation generated by SET and a migratorial process via a phenonium ion intermediate is proposed.
Silver(I)-Mediated CH Amination of 2-Alkenylanilines: Unique Solvent-Dependent Migratory Aptitude
作者:So Won Youn、Tae Yun Ko、Min Jung Jang、Su San Jang
DOI:10.1002/adsc.201400759
日期:2015.1.12
A highly effective silver(I)‐mediated CHamination of 2‐alkenylanilines has been developed to afford a diverse range of substituted indoles. High functional group tolerance, broad substrate scope, simple/fast/high‐yielding reaction, and recovery/reuse of the inexpensive silver oxidant are noteworthy. Furthermore, an uncommon migratory process of β‐monosubstituted 2‐alkenylanilines with solvent‐dependence
Palladium-Catalyzed Sequential Vinylic C–H Arylation/Amination of 2-Vinylanilines with Aryl boronic Acids: Access to 2-Arylindoles
作者:Ruixia Yu、Dejun Li、Fanlong Zeng
DOI:10.1021/acs.joc.7b02728
日期:2018.1.5
A palladium-catalyzed selective and successive vinylic C–H arylation/amination of 2-vinylanilines with arylboronic acids to generate indoles has been developed. This procedure represents a straightforward and practical approach to valuable multifunctionalized indoles.
Iodine(III) Reagent-Mediated Intramolecular Amination of 2-Alkenylanilines to Prepare Indoles
作者:Chun-Yang Zhao、Kun Li、Yu Pang、Jia-Qing Li、Cui Liang、Gui-Fa Su、Dong-Liang Mo
DOI:10.1002/adsc.201701551
日期:2018.5.16
A variety of 3‐substituted and 2,3‐disubstituted indoles were synthesized efficiently in good yields through the intramolecular amination of 2‐alkenylanilines promoted by readily available iodine(III) reagents in a short reaction time. Mechanistic studies showed that the reaction pathway went through a nitrenium ion and that 3‐acetoxy indoline was the key intermediate in the indole formation. The indole
Unusual 1,2-aryl migration in Pd(<scp>ii</scp>)-catalyzed aza-Wacker-type cyclization of 2-alkenylanilines
作者:So Won Youn、So Ra Lee
DOI:10.1039/c5ob00361j
日期:——
Hegedus aza-Wacker indole synthesis, we were intrigued with the fate of the aminopalladation intermediate if syn β-hydrogen is made inaccessible or unavailable. In contrast to our previously reported β-carbon elimination, cyclization of a variety of 2-alkenylaniline substrates under electrophilic palladium conditions unexpectedly afforded C3-substituted indoles. This unusual 1,2-migratory process was