Photoassisted oxidation of ruthenium(ii)-photocatalysts Ru(bpy)32+ and Ru(bpz)32+ to RuO4: orthogonal tandem photoredox and oxidation catalysis

Abstract

Common photoredox catalysts Ru(bpy)₃²⁺ and Ru(bpz)₃²⁺ are rapidly converted into Ruthenium(VIII)-oxide through continuous visible light irradiation in the presence of NaIO₄ or H₅IO₆. This hitherto unreported photoassisted catalyst oxidation was utilized in the development of tandem catalytic protocols which combine a photoredox reaction with a subsequent RuO₄-mediated oxidation. The new concept was demonstrated through one-pot radical cation Diels–Alder (RCDA)/1,5-diene cyclisation sequences.