The structure of the ring-opened product from direct oxidation of meso-tetra-arylporphyrins has been controversial for three decades. Herein we show that bilitrienones 2 are obtained from oxidation of metal-free dodecasubstituted porphyrins 1 in the presence of sodium nitrite, trifluoroacetic acid, and air oxygen. The presence of the para-nonyl groups in 1b stabilized the corresponding bilitrienone 2b, which was characterized by X-ray crystallography. In the absence of the para-nonyl groups bilitrienone 2a undergoes a rapid hydration reaction, giving biladienone 3a as the major isolated product. The molecular structures of 2b and 3a, and the photochemical isomerization of 3a are discussed. © 2009 Elsevier Ltd.
Publication Source (Journal or Book title)
Ongayi, O., Vicente, M., Ghosh, B., Fronczek, F., & Smith, K. (2010). Bilitrienones from the chemical oxidation of dodecasubstituted porphyrins. Tetrahedron, 66 (1), 63-67. https://doi.org/10.1016/j.tet.2009.10.098