Starting from simple anilines and ester arylpropiolates, an efficient one-pot synthesis of 2-arylindole-3-carboxylate derivatives has been developed through copper-mediated sequential hydroamination and cross-dehydrogenative coupling (CDC) reaction. The initial hydroamination of anilines to ester arylpropiolates in benzene can proceed in a stereoselective manner to give ester (Z)-3-(arylamino)acrylates
arylnitrones and diazo compounds by C–H activation/[4 + 1] annulation with a C(N2)–C(acyl) bond cleavage is reported, and 2,3-disubstituted NH indoles are directly synthesized in up to a 94% yield. A variety of functional groups are applicable to this reaction to give the corresponding products with high selectivity. Compared to other previously reported Rh(III)-catalyzed synthesis of homologous series, this method
I2-Catalyzed Indole Formation via Oxidative Cyclization of N-Aryl Enamines
作者:Zhiheng He、Weiping Liu、Zhiping Li
DOI:10.1002/asia.201100045
日期:2011.6.6
Cat.′s Is: An I2‐catalyzed synthesis of indoles, taking advantage of intramolecular dehydrogenative coupling reactions of enamines, afforded a variety of multifunctionalized indole derivatives in good to excellent yields under transition‐metal‐free reaction conditions.
Selective Synthesis of Indoles by Cobalt(III)-Catalyzed C–H/N–O Functionalization with Nitrones
作者:Hui Wang、Marc Moselage、María J. González、Lutz Ackermann
DOI:10.1021/acscatal.5b02937
日期:2016.4.1
redox-neutral annulation of alkynes by differently decorated nitrones set the stage for a step-economical access to indoles with ample substrate scope. The redox-neutral C–H/N–O functionalization process proceeded through kinetically relevant C–H activation by carboxylate assistance, and displayed an excellent site- and regio-selectivity with unsymmetrical nitrones and alkynes.
Multisubstituted indoles were synthesized via a one-pot tandem copper-catalyzed Ullmann-type C–N bond formation/intramolecular cross-dehydrogenativecoupling process at 130 °C in DMSO. The methodology allows practical and modular assembly of indoles in good to excellent yields from readily available aryl iodides and enamines.