A novel and efficient method for the generation of phosphinoyl radicals from the combination of diphenyliodonium salt (PhI,OTf) with triethylamine (EtN) in the presence of secondary phosphine oxides is reported. By employing this practical and simple approach, a large variety of 6-phosphorylated phenanthridines have been synthesized through the addition of phosphinoyl radicals to isonitriles as radical acceptors. The reaction works smoothly in the absence of any transition metal or photocatalyst. On the basis of electron paramagnetic resonance (EPR) and density functional theory (DFT) calculations, the mechanism of this reaction is discussed.

A derivatization of dialkylbiarylphosphines consisting in the formal replacement of their distal aryl group by a pyrimidinium betaine is reported. Two achiral representatives of this new class of Buchwald-type phosphines have been successfully synthesized through two strategies. The first one is based on a last stage introduction of the phosphino moiety, and the second one consists in a modular, one-pot, three-step procedure starting from an o-bromoaryl phosphine. The resulting phosphines have been coordinated onto gold(I) and palladium(II) centers and have been employed as supporting ligands in Pd-catalyzed Suzuki−Miyaura cross-coupling of aryl halide substrates.