Quinoxaline Synthesis from (alpha)-Hydroxy Ketones via a Tandem Oxidation Process Using Catalysed Aerobic Oxidation

The direct conversion of (alpha)-hydroxy ketones into quinoxalines via metalcatalysed aerobic oxidation followed by in situ trapping with aromatic 1,2diamines is reported. Catalyst screening indicated that these transformations could be carried out efficiently using 2 mol% Pd(OAc)2 or RuCl2(PPh3)3TEMPO; the palladium system was utilised for a range of transformations.