Evaluation of Transition Metal Catalysts in Electrochemically Induced Aromatic Phosphonation.

摘要: Voltammetry provides important information on the redox properties of catalysts (transition metal complexes Ni, Co, Mn, etc.) and their activity in electrocatalytic reactions aromatic C–H phosphonation presence a phosphorus precursor, for example, dialkyl-H-phosphonate. Based catalytic current growth oxidation or reduction (CoII, MnII, NiII, MnII/NiII, MnII/CoII, CoII/NiII), quantitative characteristics regeneration were determined, NiII CoII/NiII pairs. Calculations confirmed previously made synthetic observations synergistic effect certain ions binary systems (MnIIbpy/NiIIbpy NiIIbpy/CoIIbpy); mixtures, observed rate constants, TOF, 690 s−1 721 s−1, respectively, product yields higher monometallic (up to 71% bimetallic ~30% systems). In some cases, appearance pre-waves after adding H-phosphonates preceding chemical reaction. It also formation phosphonates time scale voltammetry, oxidizing reducing at lower potentials than original (RO)2P(O)H complex, which could be used fast diagnostics ion dialkyl-H-phosphonate interactions. Electrochemical transfer an electron (from) phosphonate generates phosphonyl radical, can then react with different arenes give products phosphonation.