Synthesis of indaphyrins: meso-tetraarylsecochlorin-based porphyrinoids containing direct o-phenyl-to-beta-linkages.
The synthesis of indaphyrins, novel meso-tetraarylsecochlorin-derived chromophores incorporating o-phenyl-to-beta-linkages, is described. Oxidative diol cleavage of meso-tetraaryl-2,3-dihydroxy-2,3-chlorins results in the formation of a secochlorin bisaldehyde. Depending on the reaction conditions during the ring cleavage reaction, one or two of the aldehyde groups react with the adjacent o-phenyl positions, leading to an intramolecular electrophilic aromatic substitution of the o-phenyl proton, and the establishment of a direct o-phenyl-to-beta-linkage. The initially formed carbinol is spontaneously oxidized to the corresponding ketone. This modification forces the aryl groups into co-planarity with the macrocycle, allowing for interactions between the pi-electrons of the aryl groups, the ketone linkage, and those of the chromophore, resulting in a significant electronic modulation of the porphyrinic pi-system. The UV-vis spectroscopic properties of the free base, CuII, NiII, and ZnII indaphyrins are discussed.
McCarthy
Jason R
JR
University of Connecticut, Department of Chemistry, Storrs, CT 06269-3060, USA.
Hyland
Michael A
MA
Brückner
Christian
C
D003198:Computer Simulation; D003300:Copper / Q000737:chemistry; D003500:Cyclization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry
D006576:Heterocyclic Compounds, 4 or More Rings; D011166:Porphyrins; C409084:tetraphenylporphyrin; D003300:Copper; D009532:Nickel; D015032:Zinc