Regioselective (thio)carbamoylation of 2,7-di-tert-butylpyrene at the 1-position with iso(thio)cyanates

Abstract

It has been found that 2,7-di-tert-butylpyrene reacts with aliphatic iso(thio)cyanates in the presence of trifluoromethanesulfonic acid to exclusively afford the corresponding 1-substituted (thio)amides in high yields. For aromatic iso(thio)cyanates the reaction is less regioselective, although substitution at the 1-position prevails. For ethoxycarbonyl isothiocyanate, apart from the 1-substituted thioamide, 1,8-disubstituted thioamide and 2,7-di-tert-butylpyrene-1-carbonitrile are formed (especially at longer reaction times).