Ligand‐to‐Metal Charge Transfer of Ag(II) CF ₂ X Carboxylates: Quantum Yield and Electrophotocatalytic Arene Fluoroalkylation Tuned by X

Abstract

Abstract Incorporation of CF 2 X groups beyond CF 3 into arene scaffolds is underdeveloped despite these groups’ utility as halogen‐bond donors and as precursors to bioisosteres. Herein, we report the synthesis, characterization, and comparative photochemistry of a suite of [Ag(II)(bpy) 2 O 2 CCF 2 X] + and Ag(II)(bpy)(O 2 CCF 2 X) 2 (bpy = 2,2´‐bipyridine, X = F, CF 3 , Cl, Br, H, CH 3 ) carboxylate complexes. We find a dramatic effect of the X substituent on the efficiency of generating CF 2 X radicals by ligand‐to‐metal charge transfer (LMCT), with Ag(II) photoreduction rates varying by over an order of magnitude and quantum yields spanning over 20%. We provide insight into how electronic and structural perturbations of the Ag(II)–O 2 CCF 2 X core are manifested in the LMCT quantum efficiency. With this information in hand, Ag(II)‐mediated electrophotocatalytic CF 2 X functionalization is carried out on a range of (hetero)arenes. This work expands the nascent field of Ag(II)‐based photocatalysis by allowing for (hetero)aryl–CF 2 X functionalization directly from unactivated fluoroalkyl carboxylate precursors.