Annulation and Arylation Stabilize New Porphyrinoids

Abstract

More pi, please! A free-base, benzannelated triphyrin with a [2.1.1] bridging pattern (1) and an azulene-derived tetracationic all-carbon porphyrinoid (2) are discussed. Compound 1 can be used to form metal triphyrin complexes, and 2 shows potential in molecular electronics and as a receptor for weakly binding anions.

Subphthalocyanines, Subporphyrazines, and Subporphyrins: Singular Nonplanar Aromatic Systems

“…336 The formation of triphyrin(2.1.1) occurs by a mechanism which is not clear, although participation of an azafulvene or an azafulvenium cation in the cyclization procedure is likely. 341 When the same synthetic protocol is employed but using 3,4diethylpyrrole as starting material, the corresponding diethylsubstituted [14]triphyrin(2.1.1) is obtained (Scheme 36, method A). Two other procedures have been reported for the synthesis of the pyrrolic series.…”

“…The formation of triphyrin(2.1.1) occurs by a mechanism which is not clear, although participation of an azafulvene or an azafulvenium cation in the cyclization procedure is likely …”

Synthesis and Properties of Ferrocenylmethylene‐Bridged Calix[4]azulene and a New Example of Bis(1‐azulenyl)ferrocenylmethylium Ion

“…Recently, the generation of the tetracationic species of the methylene-bridged calix [4]azulene derivative by reaction with DDQ was reported. [8] Therefore, it would seem that the ferrocene substituents in the ferrocenylmethylenebridged calix [4]azulene affect the hydride abstraction reaction with DDQ. …”

Annulated Isomeric, Expanded, and Contracted Porphyrins

“…Needless to say, the π-annulation of corroles is much less well-explored. Among others, an alternate synthetic approach to new corroles that stabilizes the corrole unit though the extended π-conjugation achieved via annulation with suitable aromatic moieties would be of particular interest . The limited methods to synthesize functionalized corroles have led researchers to explore reactions on the periphery of corroles by using them as substrates toward more complex functionalized corroles. − Thus, corroles undergo bromination, , nitration, amination, and cycloaddition , reactions at their meso and β-pyrrolic positions.…”