83242-12-0Relevant academic research and scientific papers
The Photochemical Reaction between 1,4-Dicyanonaphthalene and benzyl ethers
D'Alessandro, Nicola,Mella, Mariella,Fasani, Elisa,Toma, Lucio,Albini, Angelo
, p. 5043 - 5050 (2007/10/02)
Irradiation of 1,4-dicyanonaphthalene (DCN) and benzyl methyl ether gives the two diastereoisomeric 1-substituted 1,2-dihydronaphthalenes. A stereochemical assignment for these products, and related diastereoisomers pairs is proposed. The reaction occurs via the free radical ions and the low quantum efficiency is due to the slow deprotonation of the radical cation, with only moderate salt effect. In accordance with this scheme, the reaction with benzyl 1-menthyl ether gives a low enantiomeric eccess.
Photochemical Reaction between 1,4-Naphthalenedicarbonitrile and α-Substituted Benzylic Derivatives
Sulpizio, Ada,Albini, Angelo,d'Alessandro, Nicola,Fasani, Elisa,Pietra, Silvio
, p. 5773 - 5777 (2007/10/02)
The photochemical reaction of 1,4-naphthalenedicarbonitrile (NDN) with benzylic derivatives of the general formula PhCHRX (R = H, Ph; X = H, C, O, S, Si, Sn-bonded substituents) has been investigated.The competition between C-H and C-X bond cleavage in the photochemically created radical cation PhCHRX(.+) is revealed by the different chemical products formed, viz. 5,11-methanodibenzocyclooctenes (2), from proton transfer and coupling of the radicals within the cage, and 2-benzyl- (3) and 1-benzyl-1,2-dihydronaphthalenes (4), as well as 4-benzyl-1-naphthalenenitriles (5), from the reaction between the radical anion NDN(.-) and the neutral radicals PhCHR(.) or PhCRX(.).With the alcohols, the hydroxylic proton is easily transferred.Measurement of reaction quantum yield and fluoroscence quenching and thermochemical calculations support the mechanism proposed.
THE PHOTOCHEMICAL REACTION OF 1,4-NAPHTHALENEDICARBONITRILE WITH AROMATIC PINACOLS AND PINACOL ETHERS
Albini, A.,Mella, M.
, p. 6219 - 6224 (2007/10/02)
Irradiation of 1,4-naphthalenedicarbonitrile (NDN) in deoxygenated acetonitrile in the presence of aromatic pinacols (1) leads to reduction of the former to the dihydro derivative 4 and the tetrahydro derivative 5 as well as to oxidative cleavage of the latter to yield ketones or aldehydes (3).Reaction with pinacol ethers (2) leads to product types 3,4 and 5 as well as to 1(1-methoxybenzyl)-1,2-dihydro NDN derivatives (two diastereoisomers, 6 and 7).Only one of these adducts is formed in the reaction of NDN with benzyl methyl ether (8).The reaction involves electron transfer to singlet excited NDN and cleavage of the radical cations 1+. and 2+. to yield α-hydroxy and α-methoxy radicals, respectively.These react with NDN by proton transfer in the first case, and by carbon-carbon bond formation in the latter.The stereoselectivity observed in the adduct formation with 8 is explained by deprotonation of the radical cation and reaction of the corresponding radical with NDN-. in the geminate solvent cage.The mechanism of these reactions is discussed in the light of a recent flash-photolysis study.
THE PHOTOCHEMICAL REACTION BETWEEN 1,4-DICYANONAPHTALENE AND METHYLBENZENES ELECTRON TRANSFER AND FORMATION OF BENZYLIC RADICALS
Albini, A.,Fasani, E.,Oberti, R.
, p. 1027 - 1034 (2007/10/02)
The photochemical reaction of 1,4-dicyanonaphtalene (1) in the presence of methylbenzenes (2a-c) in acetonitrile affords 1-benzyl-4-cyanonaphtalenes (3), 1-benzyl-1,4-dicyano-1,2-dihydronaphtalenes (4), 2-benzyl-1,4-dicyano-1,2-dihydronaphtalenes (5 and 6) and the tetracyclic derivatives 7 and 8.Compounds 3, 7 and 8 are not the products of subsequent transformations of compound 4.No photochemical reaction is observed in non-polar media, in which, on the contrary, exciplex emission is detected.Experiments in the presence of electron acceptors, electron donors and strong acids support the idea that the reaction is initiated by electron transfer from the methylbenzenes to singlet excited 1, followed by protolytic equilibrium of the benzylic radical cation to the corresponding radical, which is the attacking species.
