Synthesis of quinoxalines through iodine-catalyzed one-pot annulation of alkynes with o-phenylenediamines

The synthesis of N-heterocycles of quinoxalines has been developed by an efficient protocol of one-pot annulation of alkynes with o-phenylenediamines. A variety of quinoxalines were prepared in good to high yields in the presence of catalytic amount of iodine as a catalyst.