Tetracyanobenzene, solid state

Type of reaction C-C bond formation Reaction condition solid-state Keywords tetracyanobenzene, benzyl reaction... 

Contrary to previous reports, acridizinium bromide yields all four isomeric [4+4]photodimerisation products both in solution and in the solid state. 2-Cyano-6,6-dimethyl-2-cyclohexenone undergoes photoaddition to 2,3-dimethyl-2-butene to give tricyclic[c,d]fused isoxazole (146) in 92% yield, possibly involving the triplet biradical (144) and the nitrene (145). With 2-methyI-2-butene and 2-methylpropene, isoxazoles (147) and (148) respectively are formed, though products from competitive formation of triplet biradical (149) are also found.The crystalline 1 2 adducts of 1,2,4,5-tetracyanobenzene with benzyl cyanide yield the coupling product (150) on irradiation this involves electron and proton transfer, radical coupling and tautomerisation steps. In solution (150) is not formed. 

Solid-state irradiation of two component molecular crystals of thienylacetic acids with aza aromatic compounds (acridine and phenanthridine) ° results in photodecarboxylation and gives decarboxylated and condensation products. Two-component molecular crystals of the above azo aromatic compounds with 3-indolepropionic acid and 1-naphthylacetic acid, upon solid-state irradiation, give radical intermediates via electron transfer and ultimately afford decarboxylated compounds in near quantitative yield. Irradiation of crystalline charge-transfer complexes of 3-indoleacetic acid and 2-naphthylacetic acid with 1,2,4,5-tetracyanobenzene gives methylnaphthalene (decarboxylation) and naphthyl(2,4,5-tricy-ano)methane (dehydrocyanating condensation) in the solid state. 

Koshima, H., Ding, K., Chisaka, Y., Matsuura, X, Ohashi, Y, and Mukasa, M., Solid-state photodecarboxylation induced by exciting the CT bands of the complexes of arylacetic adds and 1,2,4,5-tetracyanobenzene,/. Org. Chem., 61, 2352, 1996. 

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