Copper-Catalyzed Aerobic Selective Oxidation of Tetrahydrocarbolines

ABSTRACT: We report a safe and convenient open-flask coppercatalyzed selective oxidation/functionalization methodology for tetrahydrocarbolines and tetrahydro-fi-carbolines that employs atmospheric O2 as the terminal oxidant. The system is applicable to oxidative rearrangement of tetrahydro-fi-carbolines, tetrahydrocarboline oxidation to a-alkoxy carbazoles and spirooxindoles, and Witkop oxidation. Mechanistic experiments indicated that a singleelectron oxidation process is responsible for the tunable selectivity control. This copper-catalysis protocol represents a significant advance in the field of indole oxidation.

Automated summary

This study reports a safe and convenient copper-catalyzed selective oxidation method using atmospheric oxygen as the oxidant. The method allows for the oxidative rearrangement of indole compounds, leading to the formation of various functionalized products. This represents a significant advance in the field of indole oxidation.