Anomalous Intramolecular C−H Insertion Reactions of Rhodium Carbenoids: Factors Influencing the Reaction Course and Mechanistic Implications
作者:J. Stephen Clark、Alexander G. Dossetter、Yung-Sing Wong、Robert J. Townsend、William G. Whittingham、C. Adam Russell
DOI:10.1021/jo049900e
日期:2004.5.1
the expected 3(2H)-furanones formed by conventional carbenoidC−Hinsertion. These acetals are the favored C−Hinsertion products in certain circumstances and particularly in cases where carbenoid generation is effected using an electron-deficient rhodium complex. Experiments with simple deuterium labeled substrates reveal that anomalous C−Hinsertion products arise by a mechanism that is distinct from
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 isotopeeffects 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