305831-41-8Relevant academic research and scientific papers
A new synthesis of porphyrins: Via a putative trans-manganese(iv)-dihydroxide intermediate
Biswal, Himansu S.,Jena, Subhrakant,Kar, Sanjib,Mondal, Sruti,Patra, Bratati,Sahu, Kasturi
, p. 1424 - 1432 (2020/02/15)
A new method for the synthesis of meso-substituted porphyrins was developed. In this two-step methodology, the first step involves the condensation of pyrroles/dipyrromethanes with aldehydes in a water-methanol mixture under acidic conditions. The second step involves manganese induced cyclization followed by oxidation via PhIO/O2. This methodology has been useful for the synthesis of a wide range of trans-A2B2 porphyrins and also symmetric porphyrins in moderate to good yields. A detailed investigation of the manganese induced cyclization reaction has allowed us to characterize a Mn-porphyrinogen complex. A series of analytical and spectroscopic techniques and DFT calculations have led us to the conclusion that the putative intermediate species are trans-manganese(iv)-dihydroxide complexes. EPR and magnetic susceptibility measurements helped us to assign the oxidation state of the manganese complexes in their native state. The assumption of trans-manganese(iv)-dihydroxide as the true intermediate for this porphyrin synthesis has been authenticated via in situ UV-Vis experiments. This new methodology is certainly different from other previously reported methodologies in many aspects and most importantly these reactions can be easily performed on a gram scale for the synthesis of porphyrins.
Synthesis of meso-substituted corroles and porphyrins using iodine as a catalyst
Chauhan, Shive M S,Dandia, Anshu
, (2020/10/02)
Abstract: Different types of corroles and porphyrins are synthesized from substituted aldehydes and pyrrole. The current synthetic method involves iodine as catalyst and proceeds at room temperature itself. By varying the amounts of reactants (i.e., pyrrole and aldehydes), the corrole and porphyrins were obtained in good to excellent yields. These products were characterized by 1H-NMR, UV-visible, and HRMS techniques. The reaction approach utilizes the readily available pyrrole and substituted aldehydes as starting materials and makes this reaction highly attractive in diversity-oriented synthesis. Graphic abstract: Different types of porphyrins and corroles are synthesized from substituted aldehydes and pyrrole using iodine as a catalyst and the reaction proceeds at room temperature itself. By varying the amount of reactants (i.e. pyrrole and aldehydes), the porphyrins and corroles are obtained in good to excellent yields.[Figure not available: see fulltext.]
Application of [Co(Corrole)]– Complexes in Ring-Closing C–H Amination of Aliphatic Azides via Nitrene Radical Intermediates
Goswami, Monalisa,Geuijen, Paul,Reek, Joost. N. H.,de Bruin, Bas
, p. 617 - 626 (2018/02/06)
The synthesis, characterisation and application of anionic [CoII(Cor)]– (Cor = corrole) metalloradicals in the ring-closing C–H amination of an aliphatic azide in the presence of Boc2O (Boc = tert-butyloxycarbonyl) to give the corresponding Boc-protected N-heterocyclic product tert-butyl 2-phenylpyrrolidine-1-carboxylate are reported. This is the first example of the use of metalloradical cobalt(II) corrole complexes in nitrene-transfer reactions. On the basis of DFT calculations, the reaction is proposed to proceed via discrete open-shell nitrene radical intermediates bearing most of their spin density at the nitrene nitrogen atom. The [CoII(Cor)]– complexes are substantially faster catalysts than the corresponding neutral [CoII(porphyrin)] complexes when applied in the same ring-closing C–H amination reaction under identical reaction conditions. Increasing the electron density at cobalt(II) therefore has a positive influence on the reaction rate.
Selective Synthesis of Tripyrranes, Tetrapyrranes, and Corroles
Aydin, Gokcen,Temelli, Baris,Unaleroglu, Canan
, p. 7583 - 7593 (2016/01/25)
A new, catalytic, and general methodology was developed for the direct synthesis of unsymmetrical AB-type tripyrranes by reaction of dipyrromethanesulfonamides with pyrrole. Key structure dipyrromethanesulfonamides were synthesized by the addition of meso
Cobalt triarylcorroles containing one, two or three nitro groups. Effect of NO2 substitution on electrochemical properties and catalytic activity for reduction of molecular oxygen in acid media
Li, Bihong,Ou, Zhongping,Meng, Deying,Tang, Jijun,Fang, Yuanyuan,Liu, Rui,Kadish, Karl M.
, p. 130 - 139 (2014/06/24)
Cobalt(III) triarylcorroles containing 0-3 nitro groups on the para-position of the three meso-phenyl rings of the macrocycle were synthesized and characterized by electrochemistry, mass spectrometry, (UV-vis) and 1H NMR spectroscopy. The examined compounds are represented as (NO2Ph)nPh3 - nCorCo(PPh3), where n varies from 0 to 3 and Cor represents the core of the corrole. Each compound can undergo two metal-centered one-electron reductions leading to formation of Co(II) and Co(I) derivatives in CH2Cl2 or pyridine containing 0.1 M tetra-n-butylammonium perchlorate (TBAP). A stepwise two electron reduction of each NO2Ph group of the compound is also observed. The first is reversible and occurs in a single overlapping step at the same potential which involves an overall one-, two- or three-electron transfer process for compounds 2-4, respectively. This indicates the lack of an interaction between these redox active sites on the corroles. The second reduction of the NO2Ph groups is irreversible and located at a potential which overlaps the Co(II)/Co(I) process of the compounds. Thin-layer UV-visible spectroelectrochemical measurements in CH2Cl2, 0.1 M TBAP demonstrate the occurrence of an equilibrium between a Co(III) π-anion radical and a Co(II) derivative with an uncharged macrocycle after the first controlled potential reduction of the nitro-substituted corroles. All four cobalt corroles were also examined as catalysts for the electroreduction of O2 when coated on an edge-plane pyrrolytic graphite electrode in 1.0 M HClO4. This study indicates that the larger the number of nitro-substituents on the cobalt corrole, the better the compound acts as a catalyst.
Synthesis of meso-tetraphenyl porphyrins via condensation of dipyrromethanes with N-tosyl imines
Temelli, Baris,Unaleroglu, Canan
experimental part, p. 2043 - 2050 (2009/07/18)
A new synthetic route for the synthesis of 5,10,15,20-tetraphenyl porphyrins has been developed based on the reaction of 5-substituted dipyrromethanes with N-tosyl imines in the presence of a metal triflate catalyst. meso-Substituted tetraphenyl porphyrins were synthesized in a two-step process. The first step of the method is the metal triflate-catalyzed condensation of 5-substituted dipyrromethanes with N-tosyl imines to form a porphyrinogen intermediate and the second step is the oxidation of the porphyrinogen to porphyrin. The method was applied to the synthesis of trans-A2B2-tetraarylporphyrins and the products were obtained with only a trace amount of one scrambling product. The synthesis of two important building blocks for porphyrin synthesis, mono and di-sulfonamide alkylated 5-substituted dipyrromethanes, was achieved by the addition of 5-substituted dipyrromethane to N-tosyl imine. The application of mono and di-sulfonamide alkylated 5-substituted dipyrromethanes in '2+2' porphyrin formation reactions is presented.
Organocatalytic synthesis of dipyrromethanes by the addition of N-methylpyrrole to aldehydes
Biaggi, Cinzia,Benaglia, Maurizio,Raimondi, Laura,Cozzi, Franco
, p. 12375 - 12379 (2007/10/03)
The reaction of aldehydes with N-methylpyrrole carried out in the presence of catalytic pyrrolidinium tetrafluoroborate at room temperature affords the corresponding dipyrromethanes and minor amounts of tripyrranes. This new, mild, and convenient process
Efficient synthesis of meso-substituted corroles in a H2O-MeOH mixture
Koszarna, Beata,Gryko, Daniel T.
, p. 3707 - 3717 (2007/10/03)
New and efficient conditions for the synthesis of meso-substituted corroles were developed. The first step, involving the reaction of aldehydes with pyrrole, was carried out in a water-methanol mixture in the presence of HCl. A relatively narrow distribut
Synthesis of Corroies Bearing up to Three Different Meso Substituents
Guilard, Roger,Gryko, Daniel T.,Canard, Gabriel,Barbe, Jean-Michel,Koszarna, Beata,Brandes, Stephane,Tasior, Mariusz
, p. 4491 - 4494 (2007/10/03)
(Matrix Presented) We have developed a new method that affords regioisomerically pure corroles possessing up to three different substituents at the meso positions. The corrole formation reaction involves the acid-catalyzed condensation of a dipyrromethane
Triarylcorroles by oxidative coupling of triaryltetrapyrranes
Bri?as,Brückner
, p. 442 - 444 (2007/10/03)
A general two-step, one-pot synthesis of meso-triphenylcorrole from 5-phenyldipyrrane is presented. A number of p-phenyl-substituted 5-phenyldipyrranes were condensed with substituted benzaldehydes under acid catalyzed conditions to produce a mixture high
