Regioselective Radical Arylation: Silver-Mediated Synthesis of 3-Phosphorylated-Coumarins, Quinolin-2(1H)-one and Benzophosphole Oxides
A silver-mediated domino radical addition/cyclization reaction of diarylphosphine oxides with propynoic acid derivatives were described. The reaction products of diarylphosphine oxides with alkynoates or propynoic amide in different regioselectivities, giving 3-phosphorylated coumarins and benzophosphole oxides in moderate to good isolated yields, respectively. The hydrogen bond between the P=O and NH was proposed to assist the vinyl radical regioselective arylation process. Dialkylphosphine oxides also compatible, and gave the 3-phosphorylated-coumarins and quinolin-2(1H)-one in good yields.
- This article is part of the themed collection: Synthetic methodology in OBC