83242-06-2

Upstream product

• 67-56-1 methanol 
• 3029-30-9 naphthalene-1,4-dicarbonitrile 
• 770-09-2 benzyltrimethylsilane 
• 28493-54-1 benzyltributyltin 
• 102505-27-1 1-(Diphenylmethyl)-1,2-dihydro-1,4-naphthalenedicarbonitrile 
• 108-88-3 toluene 
• 107-13-1 acrylonitrile 
• 102493-54-9 cis-2-(1,1-Diphenylmethyl)-1,2-dihydro-1,4-naphthalenedicarbonitrile 

Downstream Products

• 98689-34-0 3-Benzylnaphthalene-1-carbonitrile 

Relevant academic research and scientific papers

Benzyl radicals from toluene by photosensitization with naphthalene-1,4- dicarbonitrile - Benzylation and hydroxymethylation of unsaturated compounds

In aprotic media, photoinduced electron transfer from toluene to 1,4- naphthalenedicarbonitrile (DCN) is followed by in-cage proton transfer and radical coupling. However, in the presence of a protic co-solvent, the radical ions diffuse out of the cage and deprotonation of the toluene radical cation takes place from the free solvated species. With (BuOH, this results in reductive benzylation of DCN through coupling of benzyl radicals with DCN-·. With MeOH, secondary hydrogen abstraction by PhCH2- yields hydroxymethyl radicals, which couple with DCN-·. Both benzyl and hydroxymethyl radicals are efficiently trapped by electrophilic alkenes. Thus, in the presence of dimethyl maleate, DCN-photosensitized benzylation - or hydroxy-methylation - of the substrate occurs through direct activation of the C-H bond. The same reaction has been accomplished with acrylonitrile, albeit with a lower yield.

Set Photochemical Reactions between 1,4-Naphthalenedicarbonitrile and Benzylic Donors. Medium Effects

The electron transfer induced photochemical reactions 1,4-naphthalenedicarbonitrile (NDN) with toluene (1a), diphenylmethane (1b), p-methoxytoluene (1c), and benzyltrimethylsilane (1d) in MeOH-MeCN and 0.1 M KOH-MeOH-MeCN were examined.The results were compared with those of reactions occurring in neat MeCN.Under the former conditions, the cation radical derived from 1a undergoes deprotonation after diffusion from (rather than within) the geminate ion pair (as in MeCN).The formed benzyl radical abstracts a hydrogen from MeOH leading to hydroxymethylation of NDN competitively with its benzylation.Under basis conditions MeO(-) adds to 1a(+.) yielding 1c.The reaction of 1b in MeOH-MeCN and 0.1 M KOH-MeOH-MeCN is similar to that of 1a.However, in the reaction of 1c under these conditions, the arene cation radical undergoes deprotonation out of cage.Finally, desilylation of the cation radical from 1d is a fast process occurring from the geminate pair in all the media explored.

Photoinduced electron-transfer reactions of arylmethyl-substituted 14 group compounds: Photoarylmethylation and photooxygenation

Photoreactions of arylmethylsilanes, -germane, and -stannane with 1,4- dicyanonaphthalene (DCN) and 9, 10-dicyanoanthracene (DCA) were studied under various conditions. The arylmethylation of DCN and DCA occurred in the photoreaction under nitrogen atmosphere, whereas the oxygenation of the arylmethyl organometallic compounds occurred in the photoreaction under oxygen atmosphere. Key intermediates in these reactions in acetonitrile were radical ions which were generated via photoinduced electron transfer from the arylmethyl organometallic compounds to the excited singlet of DCN or DCA. The cleavage of the carbon-metal bond of the radical cations of the arylmethyl compounds resulted in the formation of arylmethyl radicals. The radicals reacted then with the radical anions of DCN and DCA to produce the arylmethylated compounds or reacted with oxygen to produce the oxygenated compounds. The efficiency of the photoreactions was affected by solvents and added materials to the reaction systems. In the photoreactions in benzene, the exciplexes of the type 1[A-ArCH2MR3]* or the triplexes of the type [A-C6H6-ArCH2MR3]* (A=DCN, DCA) were involved as intermediates. The reactivity features of the photoreactions are discussed.

Photochemical Reaction between 1,4-Naphthalenedicarbonitrile and α-Substituted Benzylic Derivatives

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.

ON THE MECHANISM OF THE PHOTOCHEMICAL REACTION BETWEEN 1,4-NAPHTHALENEDICARBONITRILE AND METHYLBENZENES

On the basis of the correlation between fluorescence quenching and reaction quantum yield and of deuteration studies, it is shown that the photochemical reaction between 1,4-naphthalenedicarbonitrile (NDN) and methylbenzenes involves (i) water-mediated proton transfer within the charge-transfer exciplex, (ii) in-cage reaction of the two radicals to form 2-benzyl-1,2-dihydro-1,4-naphthalenedicarbonitrile (2) and 6,11-dicyano-5,11-methano-5,6,11,12-tetrahydrodibenzocyclooctene (3), the formation of the latter product requiring a further water-mediated hydrogen transfer, and (iii) escape of the benzylic radical, which is trapped by NDN, to give 4-benzyl-1-naphthalenecarbonitrile (1), a product formed also when benzylic radicals are generated from other sources.

THE PHOTOCHEMICAL REACTION BETWEEN 1,4-DICYANONAPHTALENE AND METHYLBENZENES ELECTRON TRANSFER AND FORMATION OF BENZYLIC RADICALS

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.

Photochemical Benzylation of 1,4-Dicyanonaphthalene; X-Ray Crystal Structure of 6,11-Dicyano-5,11-methano-5,6,11,12-tetrahydrodibenzocyclo-octene

The irradiation of 1,4-dicyanonaphthalene in the presence of toluene in acetonitrile gives adducts bearing the benzyl group in positions 1 and 2 of the naphthalene nucleus; two of the isolated products arise from rearomatisation or from a further photoreaction, and the structure of one of the products has been determined by X-ray crystallography.