Decarboxylative cross-coupling reactions of substituted 2-carboxyazine N-oxides, with a variety of (hetero)aryl halides, by bimetallic Pd(0)/Cu(I) and Pd(0)/Ag(I) catalysis are reported. Two possible pathways, a conventional bimetallic-catalyzed decarboxylative arylation, as well as a protodecarboxylative/direct C-H arylation sequence have been considered. These methods provide the first general decarboxylative arylation methodology for the 2-carboxyazine series.
Keywords: 2-carboxyazine N-oxides; catalysis; cross-coupling; palladium.
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.