Aziridines. 76 - Neglected aspects of anthracenide (anthracenidyl) chemistry - Reactions with two N-benzoylaziridines

Reaction of anthracenide A(.-) with N-benzoylaziridines 1a,b forms charged radicals 3a,b by single electron transfer and homolytic ring opening. React ions follow that are known or expected as e.g. coupling with position 9 of A(.-) forming dihydroanthracene anions 9a,b that yield amidoethylated dihyd roanthracenes 10a,b, or react with 1a,b giving finally 9,10-bis-amidoethyla ted dihydroanthracenes 11a,b. Results depend on experimental conditions and on the counter ions Na+ or Li+. Coupling is not regiospecific: contributio ns by positions 2 and 1 reach 29% or 4%, respectively, of total coupling wi th the primary radical 3a; much higher contributions are possible with Li. Product 21s (probably 3,3'-disubstituted tetrahydrobianthryl) may arise by hydrogen detachment from the first intermediate (29) of coupling with posit ion 2 and dimerization of the formed 2-substituted A(.-) (30). Coupling pro ducts may be fully aromatized or may be hydroxylated in one of the benzylic positions. With counter ion Li+ a non-SET reaction of la with the dimer of A(.-) is indicated by the isolation of 9-benzoyl-dihydroanthracene 15 and by 19% yield of 16a (aromatized 10a). Reaction of 3b with anthracene is ind icated by 10,10'-disubstituted tetrahydrobianthryl 37.