Hypervalent Iodine(III)‐Mediated Oxidative Degradation of 2‐Alkoxychalcones Under Copper(II) Catalysis for the Synthesis of Unsymmetrical 1,2‐Diaryl Diketones

ABSTRACT A mild and efficient oxidative transformation of 2‐alkoxychalcones into unsymmetrical 1,2‐diaryl diketones has been achieved using [(hydroxy)tosyloxyiodo]benzene (HTIB) and catalytic Cu(OTf) 2 in acetonitrile at room temperature. The reaction proceeds via a tandem oxidative rearrangement and C─C bond cleavage pathway, delivering diketones in good to excellent yields. The protocol exhibits broad substrate scope and functional group tolerance, with the ortho ‐alkoxy group playing a crucial role. The synthetic potential of the obtained 1,2‐diketones is demonstrated by their efficient conversion into densely substituted imidazole and quinoxaline derivatives. A plausible mechanism involving hypervalent iodine‐mediated activation and copper‐assisted oxidation is proposed.