Ruthenium-catalyzed direct synthesis of quinoxalines from o-dinitrobenzene derivatives and vicinal diols

A highly efficient synthesis of quinoxalines from o-dinitrobenzene derivatives and vicinal diols is developed based on the protocol of Ru-catalyzed direct N-alkylation of nitroarenes. The o-nitroanilines rather than the corresponding diamines are also tolerated and have comparable reactivity. The diols and the nitro group act as the hydrogen donors and acceptors in this method, respectively. The scope and limitation of the method were illustrated with 20 examples and isolated yields of up to 88% were achieved. This study provides a viable synthetic approach to various quinoxaline derivatives.