Light-Induced Alkylation of (Hetero)aromatic Nitriles in a Transition-Metal-Free C–C-Bond Metathesis

A light-induced C–C-σ-bond metathesis was achieved through transition-metal-free activation of an unstrained C­(sp³)–C­(sp³)-σ-bond in 1-benzyl-1,2,3,4-tetrahydro­iso­quinolines. A photoredox-mediated single-electron oxidation of these precursor amines yield radical cations which undergo a homolytic cleavage of a C­(sp³)–C­(sp³)-σ-bond rather than the well-known α-C–H-scission. The resulting carbon-centered radicals are used in the <i>ipso</i>-substitution of (hetero)­aromatic nitriles proceeding through another single-electron transfer-mediated C–C-bond cleavage and formation

Transition-Metal-Free Decarboxylative Photoredox Coupling of Carboxylic Acids and Alcohols with Aromatic Nitriles

A transition-metal-free protocol for the redox-neutral light-induced decarboxylative coupling of carboxylic acids with (hetero)­aromatic nitriles at ambient temperature is presented. A broad scope of acids and nitriles is accepted, and alcohols can be coupled in a similar fashion through their oxalate half esters. Various inexpensive sources of UV light and even sunlight can be used to achieve this C–C bond formation proceeding through a free radical mechanism