Substitutional doping of perylene with two boron atoms at the 6b/12b positions and two oxygen or nitrogen atoms at the 1/7 positions has been achieved. The modular synthesis route developed for these bis-BO- (3) and bis-BN-perylenes (5) starts from the readily accessible borinic acid derivative of the doubly brominated 9,10-dihydro-9,10-diboraanthracene (DBA), 1,5-Br2 DBA(OH)2 . A Stille-type reaction first furnishes the alkynyl-substituted species 1,5-(RCC)2 DBA(OH)2 (2), which undergo double ring closure to afford 3 via the gold-catalyzed addition of the O-H bonds to the C≡C bonds. Treatment of 2 with MeN(SiMe3 )2 leads to aminoborane intermediates 1,5-(RCC)2 DBA(N(H)Me)2 , which can be ring-closed to give 5 in a similar manner as in the case of 3. Different substituents R (such as Me, tBuPh) can be introduced at the 2/8 positions of the perylene core. The products obtained undergo reversible reduction and are efficient blue/turquoise emitters.
Keywords: azaborines; fluorescence; heterocycles; polycycles; synthetic methods.
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