Redox-Neutral Weak Chelation-Assisted C–H Functionalization/Annulation via Carbene Insertion: Access to Benzo[ c ]oxaphosphinine Oxides

Abstract A Rh-catalyzed C–H functionalization/annulation cascade of arylphosphonic acid monoesters has been achieved employing diazo compounds as the stable carbene surrogate to furnish functionalized benzo[c]oxaphosphinine oxides. The C–C/C–O bond formation, redox-neutral conditions, site selectivity, substrate scope, and functional group diversity are the important practical features.