Mn-catalyzed oxo-alkylation of 1,2,4-triazine-3,5(2<i>H</i>,4<i>H</i>)-diones with cyclic alkanols <i>via</i> oxidative cross-dehydrogenative coupling

An efficient and convenient pathway to synthesize diverse 3 or 4-oxo-alkyl substituted 1,2,4-triazine-3,5(2<i>H</i>,4<i>H</i>)-diones has been reported <i>via</i> an atom- and step-economical cross-dehydrogenation coupling strategy with good functional group tolerance and wide substrate scope. The present transformation employs inexpensive manganese salt catalysts and iodobenzene diacetate oxidants at room temperature. The synthetic utility of this pathway is further demonstrated by a gram scale reaction.