H–D exchange between quercetin and solvent in the presence of AuI chloride complexes with DMSO: quantum chemical modeling

The pathways of H–D exchange between quercetin and solvent taking into account the effects of the medium are considered using quantum chemical calculations and the mechanism of selective H–D exchange reaction at the C(2′) position observed only in the presence of Au complexes is identified. It is shown that only the exchange processes in the A-ring have suffi- ciently low activation barriers. In the acidic and alkaline media, these processes occur at lower energies as compared with the reaction in the neutral system, which qualitatively agrees with the published experimental data. It was shown that the Au I chloride complex with DMSO is able to react with the C–H bond at the C(2′) position by the mechanism of electrophilic substitution under mild conditions.