Cobalt carbaporphyrin-catalyzed cyclopropanation

Abstract

Cobalt complexes of N-confused porphyrins and benziphthalocyanine, which both feature organometallic bonds at the macrocycle cores, catalyze the cyclopropanation of styrene with a higher trans-selectivity than the corresponding porphyrin and phthalocyanine complexes.

Effect of Solvent and Protonation/Deprotonation on Electrochemistry, Spectroelectrochemistry and Electron‐Transfer Mechanisms of N‐Confused Tetraarylporphyrins in Nonaqueous Media

“…[1] N-Confused porphyrins have unique spectral and coordination properties as compared to porphyrins [1][2][3][4][5][6][7][8][9][19][20][21][22] and have possible applications in the fields of catalysts, functional materials, molecular switches, and ion transducers as well as in the areas of coordination and supramolecular chemistry. [23][24][25][26][27][28][29][30][31][32] The electrochemistry of "normal" free-base porphyrins has been well documented in the literature, [33] but this is not the case for N-confused porphyrins for which the solution electrochemistry is characterized by multiple irreversible processes and only a few free-base derivatives have been electrochemically examined in DMF or CH 2 Cl 2 . [16,25,34] There have been no systematic studies on how changes in solvent, porphyrin ring substituents, and protonation/deprotonation reactions will affect the electrochemistry and oxidation/reduction products of N-confused free-base porphyrins in nonaqueous media, and very little is known about the spectral properties of the oxidized or reduced compounds as a function of solvent or applied oxidation/reduction potential.…”

Ruthenium N‐Confused Porphyrins: Selective Reactivity for Ambident 2‐Heteroatom‐Substituted Pyridines Serving as Axial Ligands

“…Driven by this idea, we have synthesized a pentadentate NCP ligand with a pyridine directly tethered from the inner sp 3 ‐carbon atom of the NCP core through a sulfur atom by a sulfur addition reaction of 2‐mercaptopyridine or 2,2′‐dipyridyl disulfide for mimicking the active site of the heme‐containing enzymes (e. g., cytochrome P 450 ) . In fact, the corresponding pyridine‐tethered cobalt NCP complex showed a higher catalytic activity than an unmodified cobalt NCP complex in terms of the reaction rate and turnover number (TON) for the cyclopropanation reaction of styrene with ethyl diazoacetate …”

The first manganese N-confused porphyrins catalyzed oxidation of alkene

“…Unlike N-confused porphyrin, it's alkylation products do not undergo NH-tautomerism and have only one stable form, which can form manganese(III) N-confused porphyrin having a direct carbon-manganese (Mn-C) bond [11]. The metal complexes of N-confused porphyrins have been demonstrated to be potent catalysts in cyclopropanation of styrene with high trans-selectivity [12,13] and oxygen atom transfer reactions [14]. While numerous manganese complexes of porphyrins [15][16][17][18], corroles [19][20][21][22][23], phthalocyanines [24] and related macrocycles [25] have been extensively studied as catalysts in the oxidation of organic substrates, to the best of our knowledge, no report was found for manganese N-confused porphyrins catalyzed oxidation of organic substrates so far.…”