Probing the mechanism of the anomalous intramolecular C–H insertion reaction of rhodium carbenoids by analysis of kinetic isotope effects

The mechanism of the anomalous intramolecular insertion reaction of a rhodium carbenoid into an ethereal C–H bond has been explored using deuterium labelled substrates. Comparison of primary kinetic isotope effects and analysis of ratios of diastereoisomeric deuterated products suggests the reactions leading to the anomalous and conventional C–H insertion products are mechanistically distinct and do not share a common rate-determining step.