Palladium-Catalyzed Oxidative Amination of α-Olefins with Indoles

Herein we report the use of indoles, one of the most common nitrogen-containing heterocycles in FDA-approved drugs, as nucleophiles in the Pd-catalyzed aza-Wacker reaction. This N-functionalization of indoles is a Markovnikov selective olefin functionalization of simple alkenes using catalytic Pd-(NPhth)(2)(PhCN)(2 )and O-2 as the terminal oxidant in the presence of catalytic Bu4NBr. Various substituted indoles and alkenes are found to participate; 21 examples are presented with yields ranging from 41 to 97% isolated yield. Additionally, lactams and oxazolidinones are shown to participate under the reaction conditions. Mechanistic investigations suggest that the phthalimide ligand and Bu4NBr additive slow undesired side reactions: indole decomposition and olefin isomerization, respectively.

Automated summary

In this study, we used indoles as nucleophiles in the Pd-catalyzed aza-Wacker reaction, achieving N-functionalization of indoles. By adding phthalimide ligand and Bu4NBr additive to control side reactions, high yields of the reaction were achieved.