Reaction of indoles with molecular oxygen catalyzed by metalloporphyrins

Abstract

Cobalt(II), cobalt(III), and manganese(III) meso-tetraphenylporphins catalyse the oxygenation of simple alkyl-substituted indoles, the latter complex being the most active catalyst. Spectroscopic data (uv, n.m.r., e.s.r.) indicate that during the reaction catalysed by CoTPP, a ternary complex: O 2CoTPPindole is formed initially. This complex is converted into indolenyl hydroperoxide, which decomposes to the final product under the influence of CoTPP.