Subporphyrins with an Axial BC Bond

Abstract

Axial fabrications of subporphyrins have been conveniently accomplished by the reaction of B(methoxo)triphenylsubporphyrin with Grignard reagents such as aryl-, heteroaryl-, ferrocenyl-, β-styryl-, phenylethynyl-, and ethylmagnesium bromides. The axial groups thus introduced are not conjugated with the subporphyrin core. This situation leads to effective fluorescence quenching of subporphyrins when the axial group is strongly electron donating such as 4-dimethylaminophenyl and ferrocenyl groups.

Observation of Diastereomeric Interconversions of β‐Sulfinylsubporphyrins as Evidence for Bowl Inversion

“…[13] The structure of 4 is fully consistent with its spectroscopicd ata. In addition, the structure of 4 has been confirmed by single-crystal X-ray diffraction analysis (Figure 2a).…”

Pyrrole‐Modified Subporphyrins Bearing a Sulfur‐Containing Heterocyclic Unit

“…The UV/VIS absorption spectra of 5 – 8 in CH 2 Cl 2 are shown in Figure , which are similar to that of subchlorophin 1 rather than that of subporphyrin 0 . However, the Soret ‐like bands of 5 – 7 show different features compared to that of 1 possessing only one absorption maximum; the Soret ‐like band of 6 shows one absorption maximum at 370 nm along with shoulders at 326 and 354 nm, and the Soret ‐like bands of 5 and 7 show absorption maxima at 325 and 381 nm, and 338 and 366 nm, respectively ( Table ).…”

“…The electrochemical properties of 5‐OMe , 5 – 9 , 10a , and 10b were measured by cyclic voltammetry and differential pulse voltammetry in CH 2 Cl 2 with 0.1 m tetrabutylammonium hexafluorophosphate as a supporting electrolyte (Figure and Table ). Despite the difference of the axial ‐substituent on the boron atom, dithiazolosubporphyrins 5 and 5‐OMe showed almost the same oxidation and reduction potentials. The first and second oxidation potentials of 5 were 0.25 and 0.82 V, respectively, significantly less positive than those of 1 and 6 – 8 .…”

Synthesis and characterization of π–extended “earring” subporphyrins

“…In addition the intense absorption in the UV–vis region [9–24] makes it a promising building block in pigments. The functionalization of subporphyrin can proceed at various sites such as the central boron atom [25–30], meso - [31–32] and β-position [33–35]. By using the method developed by Osuka the β,β′-diborylsubporphyrins [36] can be obtained in high yields.…”