78075-61-3

Upstream product

• 3029-30-9 naphthalene-1,4-dicarbonitrile 
• 108-88-3 toluene 

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.

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.