Ruthenium Catalyzed Directing Group-Free C2-Selective Carbenoid Functionalization of Indoles by α-Aryldiazoesters
摘要:
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.
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 %