An efficient synthesis of quaterrylenedicarboximide NIR dyes

Quaterrylenedicarboximides were prepared from 9-bromoperylene-3,4-dicarboximides by palladium-catalyzed coupling with 3-perylene boronic ester, followed by oxidative cyclo-dehydrogenation of the resulting perylene-perylenedicar-boximide dyads with iron(III) chloride. The quaterrylenedi-carboximides, described here, are highly photochemically and thermally stable dyes, which may be useful as green NIR dyes (lambda(max) = 735 nm) and as building blocks for the synthesis of higher rylene dyes.