KCS

C-H bond functionalizations catalyzed by transition metals have been demonstrated to be a very streamlined method for the formation of C-C and C-heteroatom bonds. In particular, ortho C-H bond functionalizations can be accomplished by the employment of a variety of directing groups with the aid of coordination of transition metals. In a number of directing groups for C-H bond functioalizations, nitrogen-containing compounds, carboxyl and hydroxyl ones have been broadly investigated. We report for the first time rhodium-catalyzed tandem oxidative alkenylation and intramolecular oxa-Michael reaction using arylphosphonic acid monoethyl esters and alkenes under aerobic conditions, which produced benzoxaphosphole 1-oxides in good to excellent yields.