A ruthenium-catalyzed ortho C–H arylation process is described using visible light.

A general and efficient access to aryl, heteroaryl, vinyl and alkynyl difluoromethylphosphonates is described. The developed methodology using TMSCF2PO(OEt)2, iodonium salts and a copper salt provided a straightforward manifold to reach these highly relevant products. The reaction proved to be highly functional group tolerant and proceeded under mild conditions, giving the corresponding products in good to excellent yields. This method represents the first general synthetic route to this important class of fluorinated scaffolds, which are well-recognized as in vivo stable phosphate surrogates.

The difluoromethyl phosphonate motif plays a crucial role in the development of bioactive molecules as it is considered as a phosphate bioisoster. Since 2010, a renewal of interest to enlarge the panel of reactions to access these difluoromethylated phosphonate-containing molecules has been witnessed. This Concept article charts the recent progress that has been made.