Direct C-H Phosphonylation of Electron-Rich Arenes and Heteroarenes by Visible-Light Photoredox Catalysis.

The direct transformation of ubiquitous, but chemically inert C-H bonds into diverse functional groups is an important strategy in organic synthesis that improves the atom economy and faclitates the preparation and modification of complex molecules. In contrast to the wide applications of aryl phosphonates, their synthesis via direct C-H bond phosphonylation is a less explored area. We report here a general, mild, and broadly applicable visible-light photoredox C-H bond phosphonylation method for electron-rich arenes and heteroarenes. The photoredox catalytic protocol utilizes electron-rich arenes and biologically important heteroarenes as substrates, [Ru(bpz)3 ][PF6 ]2 as photocatalyst, ammonium persulfate as oxidant, and trialkyl phosphites as the phosphorus source to provide a wide range of aryl phosphonates at ambient temperature under very mild reaction conditions.