Photocatalyst-free visible-light-promoted C(sp²)-P coupling: efficient synthesis of aryl phosphonates

A novel and efficient method for the synthesis of aryl phosphonates from aryl halides and trialkylphosphites via EDA complex-based photochemistry has been developed. It is demonstrated that aryl radicals, generated from the photoexcitation of the EDA complex formed by aryl halide and potassium thioacetate, could be intercepted with trialkylphosphite to produce the corresponding aryl phosphonates in moderate to good yields. It should be noted that the reaction is performed at room temperature in the absence of any transition metal catalyst, oxidant and photocatalyst, exhibiting high efficiency, high selectivity, and operational simplicity.