Axial Ligand Exchange Reactions of <i>meso</i>-Aryl SubporphyrinsAxially Fluoro-Substituted Subporphyrin and a μ-Oxo Dimer and Trimer of Subporphyrins

High reactivity of the boron atom of meso-aryl subporphyrins enables the introduction of a broad range of functional groups to its axial position. Axially fluoro-substituted subporphyrins were easily synthesized upon treatment of axially hydroxyl-substituted subporphyrins with BF3·OEt2. Homogeneous μ-oxo dimers of subporphyrins were formed by heating monomers in the presence of triethylamine under a high vacuum. A heterogeneous subporphyrin−phthalocyanine−subporphyrin trimer was selectively formed from the respective monomers under similar reaction conditions. Structures of these molecules were elucidated by 1H NMR spectra and a single-crystal X-ray diffraction analysis, and the interactions between neighboring chromophores in the dimeric systems were estimated from absorption and magnetic circular dichroism spectra

Axial Ligand Exchange Reactions of <i>meso</i>-Aryl SubporphyrinsAxially Fluoro-Substituted Subporphyrin and a μ-Oxo Dimer and Trimer of Subporphyrins

High reactivity of the boron atom of meso-aryl subporphyrins enables the introduction of a broad range of functional groups to its axial position. Axially fluoro-substituted subporphyrins were easily synthesized upon treatment of axially hydroxyl-substituted subporphyrins with BF3·OEt2. Homogeneous μ-oxo dimers of subporphyrins were formed by heating monomers in the presence of triethylamine under a high vacuum. A heterogeneous subporphyrin−phthalocyanine−subporphyrin trimer was selectively formed from the respective monomers under similar reaction conditions. Structures of these molecules were elucidated by 1H NMR spectra and a single-crystal X-ray diffraction analysis, and the interactions between neighboring chromophores in the dimeric systems were estimated from absorption and magnetic circular dichroism spectra

Group 10 Metal Complexes of <i>meso</i>-Aryl-Substituted [26]Hexaphyrins with a Metal−Carbon Bond

Nickel(II), palladium(II), and platinum(II) complexes of meso-aryl-substituted [26]hexaphyrin have been prepared and structurally characterized. In mono-metalated complexes, the metal ion is commonly bound with three pyrrolic nitrogen atoms and one pyrrolic β-carbon, whereas a bis-Pd(II) complex exhibits a unique structure involving a Pd−Cα bond. These results reveal novel coordination abilities of the hexaphyrin that lead to a metal−carbon bond at either pyrrolic Cβ or Cα position

Group 10 Metal Complexes of <i>meso</i>-Aryl-Substituted [26]Hexaphyrins with a Metal−Carbon Bond

Nickel(II), palladium(II), and platinum(II) complexes of meso-aryl-substituted [26]hexaphyrin have been prepared and structurally characterized. In mono-metalated complexes, the metal ion is commonly bound with three pyrrolic nitrogen atoms and one pyrrolic β-carbon, whereas a bis-Pd(II) complex exhibits a unique structure involving a Pd−Cα bond. These results reveal novel coordination abilities of the hexaphyrin that lead to a metal−carbon bond at either pyrrolic Cβ or Cα position

Group 12 Metal Complexes of [26]Hexaphyrin(1.1.1.1.1.1)

Metalation of meso-hexakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.1.1.1) (1) has been explored with group 12 metal ions Zn(II), Cd(II), and Hg(II). Zn(II) and Cd(II) ions afforded dinuclear gable-shaped complexes 2 and 3 in good yields, while Hg(II) ion provided bis-Hg(II) and mono-Hg(II) planar complexes (4 and 5) via C−H bond cleavage

Group 10 Metal Complexes of <i>meso</i>-Aryl-Substituted [26]Hexaphyrins with a Metal−Carbon Bond

Nickel(II), palladium(II), and platinum(II) complexes of meso-aryl-substituted [26]hexaphyrin have been prepared and structurally characterized. In mono-metalated complexes, the metal ion is commonly bound with three pyrrolic nitrogen atoms and one pyrrolic β-carbon, whereas a bis-Pd(II) complex exhibits a unique structure involving a Pd−Cα bond. These results reveal novel coordination abilities of the hexaphyrin that lead to a metal−carbon bond at either pyrrolic Cβ or Cα position

Group 10 Metal Complexes of <i>meso</i>-Aryl-Substituted [26]Hexaphyrins with a Metal−Carbon Bond

Nickel(II), palladium(II), and platinum(II) complexes of meso-aryl-substituted [26]hexaphyrin have been prepared and structurally characterized. In mono-metalated complexes, the metal ion is commonly bound with three pyrrolic nitrogen atoms and one pyrrolic β-carbon, whereas a bis-Pd(II) complex exhibits a unique structure involving a Pd−Cα bond. These results reveal novel coordination abilities of the hexaphyrin that lead to a metal−carbon bond at either pyrrolic Cβ or Cα position

Dearomatization-Induced Transannular Cyclization: Synthesis of Electron-Accepting Thiophene‑<i>S</i>,<i>S</i>‑Dioxide-Fused Biphenylene

The transannular cyclization of dehydroannulenes bearing several alkyne moieties in close proximity is a powerful synthetic method for producing polycyclic aromatic hydrocarbons. We report that the reactivity can be switched by the aromaticity of the ring skeletons fused with the dehydroannulene core. Thus, while thiophene-fused bisdehydro[12]­annulene 1 was handled as a stable compound in the air at room temperature, the oxidation with m-chloroperbenzoic acid from the aromatic thiophene rings to the nonaromatic thiophene-S,S-dioxides induced the transannular cyclization, even at room temperature, which was completed within 1 day to produce the formal [2 + 2] cycloadduct 3. This is in stark contrast to the fact that the thermal cyclization of 1 itself required heating at 80 °C for 9 days for completion. Experimental and theoretical studies indicate that the oxidation of even one thiophene ring in 1 sufficiently decreases the activation barrier for the transannular cyclization that proceeds through the 8π and 4π electrocyclic reaction sequence. The thiophene-S,S-dioxide-fused biphenylene 3 thus produced exhibits a set of intriguing properties, such as a higher electron affinity (E1/2 = −1.17 V vs Fc and Fc+) and a stronger fluorescence (ΦF = 0.20) than the other relevant biphenylene derivatives, which have electron-donating and nonfluorescent characteristics

Group 12 Metal Complexes of [26]Hexaphyrin(1.1.1.1.1.1)

Metalation of meso-hexakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.1.1.1) (1) has been explored with group 12 metal ions Zn(II), Cd(II), and Hg(II). Zn(II) and Cd(II) ions afforded dinuclear gable-shaped complexes 2 and 3 in good yields, while Hg(II) ion provided bis-Hg(II) and mono-Hg(II) planar complexes (4 and 5) via C−H bond cleavage

Group 12 Metal Complexes of [26]Hexaphyrin(1.1.1.1.1.1)

Metalation of meso-hexakis(pentafluorophenyl)-substituted [26]hexaphyrin(1.1.1.1.1.1) (1) has been explored with group 12 metal ions Zn(II), Cd(II), and Hg(II). Zn(II) and Cd(II) ions afforded dinuclear gable-shaped complexes 2 and 3 in good yields, while Hg(II) ion provided bis-Hg(II) and mono-Hg(II) planar complexes (4 and 5) via C−H bond cleavage