N-fusion reaction sequence of heptaphyrin(1.1.1.1.1.1.1): singly, doubly, and quadruply N-fused heptaphyrins.
meso-Heptakis(pentafluorophenyl) heptaphyrin(1.1.1.1.1.1.1) (1) was prepared by a stepwise route in 39 % yield and its unique N-fusion reaction (NFR) sequence has been revealed; this reaction leads to singly-, doubly-, and quadruply N-fused heptaphyrins (4, 5, and 6) in good yields. These transformations are facilitated by the inherent conformational distortion of 1 as well as the distorted, folded conformations of N-fused heptaphyrins 4 and 5. The proximate arrangement of the three pyrrole units in 6 allowed for the formation of the tripyrrolylboron(III) complexes 7, 8, and 9 with unique coordination features. Molecules 1, 5, and 9 were structurally characterized by X-ray crystallography. In addition, the boron complexes 7, 8, and 9 displayed weak but distinct fluorescence in the near infrared region.
Saito
Shohei
S
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Osuka
Atsuhiro
A