Site-selective and metal-free C-H phosphonation of arenes photoactivation of thianthrenium salts.

Aryl phosphonates are prevalent moieties in medicinal chemistry and agrochemicals. Their chemical synthesis normally relies on the use of precious metals, harsh conditions or aryl halides as substrates. Herein, we describe a sustainable light-promoted and site-selective C-H phosphonation of arenes thianthrenation and the formation of an electron donor-acceptor complex (EDA) as key steps.