B. Gerlach et Fp. Montforts, AZACHLORINS - SYNTHESIS OF A NOVEL TYPE OF HYDROPORPHYRINS FROM THE BILE PIGMENT BILIRUBIN, Liebigs Annalen, (8), 1995, pp. 1509-1514
Azachlorins rac-10a,b, rac-11, and rac-16, a novel type of hydroporphi
noid compounds, were synthesized from azaporphyrins 8 and 13 by regios
elective cycloaddition of singlet oxygen and further transformation by
amide acetal Claisen rearrangement. The azaporphyrins are readily acc
essible from the naturally occurring bile pigment bilirubin (5). The p
hotophysical properties of the azachlorins recommend these chlorin der
ivatives as potential photosensitizers for Photodynamic Therapy (PDT).