A mechanistic analysis of the Rh-catalyzed intramolecular C-H amination reaction

A detailed mechanistic investigation of the intramolecular dirhodium tetracarboxylate-catalyzed sulfamate ester C-H amination reaction is presented. These studies provide support for the formation of a sulfamate-derived iminoiodinane, which reacts rapidly with the rhodium catalyst to generate a nitrenoid-type oxidant. Reactivity patterns, Hammett analysis, kinetic isotope measurement, and a cyclopropane clock experiment are indicative of a concerted, asynchronous transition structure in the product-determining C-H insertion event.