AuBr3-catalyzed cyclization of o-(alkynyl)nitrobenzenes. Efficient synthesis of isatogens and anthranils

The cyclization of o-(arylalkynyl)nitrobenzenes was catalyzed by AuBr3 to produce the corresponding isatogens in good to high yields together with small amounts of anthranils. On the other hand, anthranils were obtained selectively when the AuBr3-catalyzed reaction was carried out using o-(alkylalkynyl)nitrobenzenes.