2-Substituted 3-arylindoles through palladium-catalyzed arylative cyclization of 2-alkynyltrifluoroacetanilides with arylboronic acids under oxidative conditions
Free NH 2-substituted 3-arylindoles have been prepared usually in good to high yields through the palladium-catalyzed reaction of readily available 2-alkynyltrifluoroacetanilides with arylboronic acids under oxidative conditions. The reaction tolerates a variety of useful functional groups both in the arylboronic acid and in the alkyne, including chloro, formyl, and ester groups.
Transition-metal-free, visible-light induced cyclization of arylsulfonyl chlorides with o-azidoarylalkynes: a regiospecific route to unsymmetrical 2,3-disubstituted indoles
作者:Lijun Gu、Cheng Jin、Wei Wang、Yonghui He、Guangyu Yang、Ganpeng Li
DOI:10.1039/c6cc10305g
日期:——
A visible-light-catalyzed synthesis of unsymmetrical 2,3-diaryl-substituted indoles from arylsulfonyl chlorides and o-azidoarylalkynes at room temperature has been discovered. This transformation exhibits excellent substrate scope and functional group tolerance. The use of inexpensive eosin Y as the catalyst with easy operation makes this protocol very practical.
Sequential Sonogashira/intramolecular aminopalladation/cross-coupling of <i>ortho</i>-ethynyl-anilines catalyzed by a single palladium source: rapid access to 2,3-diarylindoles
developed a practical and efficient one-pot protocol for the synthesis of 2,3-diarylindoles via Pd-catalyzed bis-arylative cyclization of various o-ethynylanilines with aryl iodides. Mechanism studies showed that a Pd-catalyzed Sonogashira reaction took place firstly, giving an internal alkyne intermediate, which subsequently underwent intramolecular aminopalladation/cross-coupling to give access to 2,3-diarylindoles
<i>tert</i>-Butyl Hydroperoxide (TBHP)-Initiated Vicinal Sulfonamination of Alkynes: A Radical Annulation toward 3-Sulfonylindoles
作者:Fei Chen、Qiang Meng、Shang-Qing Han、Bing Han
DOI:10.1021/acs.orglett.6b01427
日期:2016.7.15
novel, efficient, and facile vicinal sulfonamination of alkynes by the reaction of accessible 2-alkynyl arylazides with sulfinic acids in the presence of tert-butylhydroperoxide (TBHP) has been developed. This protocol utilizes sulfinic acids as the sulfonating reagent, azidos as the aminating reagent, and TBHP as the sulfonyl radical initiator. By using this protocol, a variety of potentially bioactive