The reaction of ethyl3-(o-trifluoroacetamidoaryl)-1-propargylic carbonates with primary or secondary amines in the presence of Pd 2 (dba) 3 , dppf, and carbon monoxide in THF at 80 °C provides ready access to free-NH indole 2-acetamides. The reaction can be applied to the synthesis of free-NH indole 2-acetic acid methyl esters.
Cp*Co(III)-catalysed selective alkylation of directed C–H bonds of arenes and heteroarenes has been accomplished employing donor–acceptor carbenes, derived from α-diazocarbonyl compounds. The developed method allows ready access to various substituted α-(hetero)aryl-α-arylacetic acid derivatives in good to excellent yields. Synthetic utility was also shown through the synthesis of a substituted indole
Enantioselective Palladium-Catalyzed Carbene Insertion into the N−H Bonds of Aromatic Heterocycles
作者:Vanessa Arredondo、Stanley C. Hiew、Eugene S. Gutman、Ilandari Dewage Udara Anulal Premachandra、David L. Van Vranken
DOI:10.1002/anie.201611845
日期:2017.4.3
C3‐substituted indoles and carbazoles react with α‐aryl‐α‐diazoesters underpalladiumcatalysis to form α‐(N‐indolyl)‐α‐arylesters and α‐(N‐carbazolyl)‐α‐arylesters. The products result from insertion of a palladium‐carbene ligand into the N−H bond of the aromatic N‐heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 %
Ruthenium Catalyzed Directing Group-Free C2-Selective Carbenoid Functionalization of Indoles by α-Aryldiazoesters
作者:Wai-Wing Chan、Shing-Hin Yeung、Zhongyuan Zhou、Albert S. C. Chan、Wing-Yiu Yu
DOI:10.1021/ol9028226
日期:2010.2.5
A directing group-free approach for C2-selective carbenoid functionalization of NH-indoles is presented. Using [RuCl2(p-cymene)](2) as catalyst and alpha-aryldiazoesters as carbenoid source, 2-alkylated indoles were obtained in up to 96% isolated yield. Similarly, a regioselective carbenoid functionalization of NH-pyrroles was also achieved.