98943-73-8

Upstream product

• 7646-66-4 N-benzoylaziridine 
• 120-12-7 anthracene 
• 14002-51-8 4-biphenyl-carboxylic acid chloride 
• 613-31-0 9,10-dihydroanthracene 

Relevant academic research and scientific papers

Reductive Ring Opening of N-Benzoylaziridine by Anthracene Hydride (Anion of 9,10-Dihydroanthracene) via Base-Induced Fragmentation of the Intermediate Carbonyl Adduct

As previously reported reaction of anthracene hydride (AH-) or of its oxa analogue xanthenyl anion (X-), with N-benzoylaziridines 1a,b can result in amidoethylation (2a,b and 3a,b) of the carboanion, in reductive opening (4a,b) of the aziridine ring, and in attack on the carbonyl group of 1a,b.We now show with 1a that both the rate of ring opening and the amount of reductive opening are significantly enhanced by an excess of AH-Li+ while the initially formed (90percent) carbonyl adduct 6a survives with a defict of AH-Li+.Both effects due to carbanion excess are absent with X-Li+ but are much stronger with AH-Na+.These results point to a rapid process that is triggered off by deprotonation at position 10 of the carbonyl adduct 6.A concerted or subsequent homolytic fragmentation is proposed to generate the ketyl 5 of 1, followed by homolytic ring opening of 5 to yield the radical 12, which is reduced to the carbanion 14.The latter forms 4 by capturing a proton from dihydroantracene.Inaccessibility of reductive ring opening for a trialkylacetyl-activated aziridine is demonstrated again (18).

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. Reactions follow that are known or expected as e.g. coupling with position 9 of A.- forming dihydroanthracene anions 9a,b that yield amidoethylated dihydroanthracenes 10a,b, or react with 1a,b giving finally 9,10-bis-amidoethylated dihydroanthracenes 11a,b. Results depend on experimental conditions and on the counter ions Na+ or Li+. Coupling is not regiospecific: contributions by positions 2 and 1 reach 29% or 4%, respectively, of total coupling with 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 position 2 and dimerization of the formed 2-substituted A.- (30). Coupling products may be fully aromatized or may be hydroxylated in one of the benzylic positions. With counter ion Li+ a non-SET reaction of 1a 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 indicated by 10,10′-disubstituted tetrahydrobianthryl 37. Wiley-VCH Verlag GmbH, 2000.

Benzylic Fragmentation of Adducts formed from Anthracene Hydride and Benzoyl Compounds: A Non-concerted Process

A carbanion intermediate (4) of the title fragmentation can be trapped by an excess of N-benzoylaziridine 1 after a long (41 h) reaction time.

Highly Regioselective Ring Cleavage of N-Acylaziridines by "Anthracene Hydride" (Anion of 9,10-Dihydroanthracene). Intermediacy of a Carbonyl Adduct. Influence of Nitrogen Inversion on the Ring Opening?

Anthracene hydride AH- reacts with N-acylaziridines by reductive opening of the aziridine ring and/or amidoethylation of AH-.When the two aziridine carbons are differently substituted, in both reactions only that bond is broken which can form the more stable carbon radical quite in accord with the intermediacy of a radical anion (ketyl) 14 and with the known homolytic cleavage of 14 forming the radical 15.The extra electron in 14 is provided by AH- being oxidized to the radical AH., which can react with 15 either by radical combination or by hydrogen transfer.The reaction of AH- with N-aroylaziridines can be interrupted at the stage of the carbonyl adduct 5 as is shown by the isolation of the ketones 7a,b.So, 5 (R4 = aryl) is considered to be in equilibrium with the radical pair AH./14.The conversion of 5 into the final products progresses as expected from its structure apart from the observed retardation by a phenyl substituent in the aziridine ring (3a, 4a).This retardation is tentatively explained by a hypothesis assuming ring opening of 14 to occur in the transition state of nitrogen inversion.The anion X- of xanthene resembles AH- in its reactivity.Both carbanions react with N-sulfonylaziridines as expected from an SN2 mechanism.