Rationalizing the Regioselectivity of Azolation of Benzylic C –H Bonds under Photoredox Catalysis

Synlett DOI: 10.1055/a-2236-1122 A density functional theory (DFT) study was performed to evaluate the reaction mechanism of the C–N bond formation under an integrated hydrogen atom transfer/radical-polar crossover photoredox catalytic cycle. The regioselective activation of a model substrate, including three reactive positions (3° benzylic C–H bond, 2° benzylic C–H bond, and primary C–Cl bond) was addressed to distinguish among the radical C–H activation mechanism and the standard SN2 reaction. We demonstrated that activation of tertiary benzylic C–H bond is the most favored and forms exclusively the experimentally observed product. In addition, the whole photoredox catalytic cycle, including the outer-sphere electron-transfer steps, was characterized computationally. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text

Source: Synlett - January 31, 2024 Category: Chemistry Authors: Sanosa, Nil Montiel-Cervantes, C ésar Rubio-Mu ñoz, Miguel Sampedro, Diego Funes-Ardoiz, Ignacio Tags: letter Source Type: research