Manganese‐Mediated Intermolecular Arylation of H‐Phosphinates and Related Compounds

The intermolecular radical functionalization of arenes with aryl and alkyl H-phosphinate esters, as well as diphenylphosphine oxide and H-phosphonate diesters, is described. The novel catalytic Mn(II) /excess Mn(IV) system is a convenient and inexpensive solution to directly convert Csp2 H into CP bonds. The reaction can be employed to functionalize P-stereogenic H-phosphinates since it is stereospecific. With monosubstituted aromatics, the selectivity for para-substitution increases in the order (RO)2 P(O)H<R(1) P(O)(OR)H<Ph2 P(O)H, a trend that may be explained by steric effects.