Heteroporphyrins and Carbaporphyrins

Porphyrinoid framework embedded with polycyclic aromatic hydrocarbons: new synthetic marvels

“…The porphyrinoids can be modified further by replacing pyrrole ring(s) with other five-and sixmembered heterocycles and carbacycles, and resulting coremodified porphyrinoids exhibit quite unique and distinct physico-chemical properties that differ very much from those of porphyrinoids. [14][15][16][17][18][19] One of the most recent unique modifications of porphyrinoids is the replacement of one or more pyrrole(s)/heterocyclic ring(s) with polycyclic aromatic hydrocarbons (PAHs) such as biphenyl, naphthalene, phenanthrene, anthracene, pyrene, and fluorene, to afford polycyclic aromatic hydrocarbon embedded porphyrinoids (Chart 1). The introduction of a PAH in place of a pyrrole/heterocycle in porphyrinoids induces new features in PAH-embedded porphyrinoids, such as different π-conjugation pathways, variable aromatic properties, an unprecedented coordination environment, significantly altered electronic properties, and unusual reactivities.…”

Organometallic Chemistry within the Structured Environment Provided by the Macrocyclic Cores of Carbaporphyrins and Related Systems

“…However, many other intriguing carbaporphyrinoid systems such as carbaporphyrins 2 and 3 [ 15 ], azuliporphyrins 4 [ 16 ], benziporphyrins 5 [ 17 , 18 ], oxybenziporphyrins 6 [ 19 ], and tropiporphyrins 7 [ 20 ] have been reported ( Figure 1 ) and these exhibit diverse structural and spectroscopic properties, unusual reactivity, and varying degrees of aromatic, nonaromatic and antiaromatic characteristics. Carbaporphyrinoids have attracted widespread interest and have been the subject of a number of reviews [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. This article focuses on the formation and reactivity of metalated carbaporphyrinoids that have carbon-metal bonds within 16-atom macrocyclic cavities.…”

Aromatic Character and Relative Stability of Pyrazoloporphyrin Tautomers and Related Protonated Species: Insights into How Pyrazole Changes the Properties of Carbaporphyrinoid Systems

“…Investigations into porphyrin-type structures has exploded over the last thirty years [ 1 , 2 , 3 ]. In 1994, two groups independently discovered N -confused porphyrins (NCPs, 1 ) ( Figure 1 ) as by-products in the acid-catalyzed condensation of pyrrole with aromatic aldehydes [ 4 , 5 ], and an efficient synthesis of this system was subsequently reported by Lindsey and Geier [ 6 ].…”