3-NO₂-5,10,15-triarylcorrolato-Cu as a versatile platform for synthesis of novel 3-functionalized corrole derivatives

Abstract

β–Nitrocorrole derivatives are potentially valuable platforms for the preparation of a wide range of more elaborated corrole derivatives possessing unique chemical functionalities and electronic properties. Here we report our results on the chemical manipulation of a copper 3-NO2-triarylcorrolate using different organic reactions, all involving the reduction of –NO2 to –NH2 at an early stage, followed by further transformations. By way of a β-acylated copper corrolate, a novel corrole derivative bearing an alkyl azide group on the peripheral positions was obtained and exploited in the Huisgen 1,3-dipolar cycloaddition.

Strategies for Corrole Functionalization

“…Paolesse and co-workers reported the reduction of 3-nitro-5,10,15-tris­( t -butylphenyl)­corrole to the corresponding amino derivative 180 as a key step to obtain the 3-functionalized amide corroles 181a – d (Scheme ). The reduction, performed with an excess of NaBH 4 in the presence of palladium supported on carbon, gave 180 in 35% yield. Acylation with anhydrides or formic acid, either performed in situ or in a two step procedure after amine isolation, afforded the target amides 181a – d in 56–71% yield.…”

Facile Generation of A2B Corrole Radical Using Fe(III) Salts and Its Spectroscopic Properties

“…Notably, β-functionalization such as halogenation, nitration, chlorosulfonation, and hydroformylation of the corrole periphery leads to the formation of novel and more sophisticated corroles. 7 Different strategies are available to prepare symmetrical and unsymmetrical corroles in good yields. 8 …”

“…Recently, corroles have emerged as an independent area of research − due to their useful applications in catalysis, sensors, molecular electronics, solar cells, nonlinear optics, and photodynamic therapy. , A number of free base corroles and their metal complexes have been synthesized and characterized over the last two decades after the invention of facile synthetic methods. Notably, β-functionalization such as halogenation, nitration, chlorosulfonation, and hydroformylation of the corrole periphery leads to the formation of novel and more sophisticated corroles . Different strategies are available to prepare symmetrical and unsymmetrical corroles in good yields …”

Corrole and nucleophilic aromatic substitution are not incompatible: a novel route to 2,3-difunctionalized copper corrolates

“…Regarding this, we have recently reported the chemical manipulation of a copper 3-NO 2 -triarylcorrolate, in which the initial reduction of -NO 2 to the -NH 2 group was followed by further transformations. 17 The amidation proceeded efficiently and different β-acylated copper corrolates were obtained, the more interesting being the derivative bearing an alkyl azide group at the peripheral positions. The use of such a compound in the Huisgen 1,3dipolar ("click") cycloaddition was also reported and represents to date one of the few examples of the application of this approach in the corrole field.…”