41969-71-5Relevant academic research and scientific papers
Stereoselectivity in the double reductive alkylation of pyrroles: Synthesis of cis-3,4-disubstituted pyrrolidines
Donohoe, Timothy J.,Harji, Rakesh R.,Cousins, Rick P. C.
, p. 141 - 142 (1999)
The preparation and Birch reduction of a 1,3,4-tri-substituted pyrrole is described: the heterocycle is loaded with electron-withdrawing groups and undergoes a double reductive alkylation reaction to yield cis-3,4-disubstituted pyrrolidines.
Synthesis and photophysical studies of a chlorin sterically designed to prevent self-aggregation
De Assis, Francisco F.,De Souza, Juliana M.,Assis, Beatriz H.K.,Brocksom, Timothy J.,De Oliveira, Kleber T.
, p. 153 - 159 (2013)
Synthesis and photophysical evaluations of a new non-aggregating chlorin derivative are described. A b-octa(carboxyethyl)porphyrin 3 was synthesized in 2 steps starting from pyrrole-3,4-dicarboxylic acid diethyl ester (2). The new chlorin derivative 6 was obtained through a 1,3-dipolar cycloaddition using benzyl azomethine ylide. Chlorin 6 presents a molecular scaffold in an "L" shape avoiding aggregation in solutions at 1-27 mM. Photophysical properties were measured, and indicate that this new compound can be considered a useful candidate for PDT studies.
Activating the Fe(I) State of Iron Porphyrinoid with Second-Sphere Proton Transfer Residues for Selective Reduction of CO2to HCOOH via Fe(III/II)-COOH Intermediate(s)
Amanullah, Sk,Saha, Paramita,Dey, Abhishek
, p. 13579 - 13592 (2021/09/11)
The ability to tune the selectivity of CO2 reduction by first-row transition metal-based complexes via the inclusion of second-sphere effects heralds exciting and sought-after possibilities. On the basis of the mechanistic understanding of CO2 reduction by iron porphyrins developed by trapping and characterizing the intermediates involved (J. Am. Chem. Soc. 2015, 137, 11214), a porphyrinoid ligand is envisaged to switch the selectivity of the iron porphyrins by reducing CO2 from CO to HCOOH as well as lower the overpotential to the process. The results show that the iron porphyrinoid designed can catalyze the reduction of CO2 to HCOOH using water as the proton source with 97% yield with no detectable H2 or CO. The iron porphyrinoid can activate CO2 in its Fe(I) state resulting in very low overpotential for CO2 reduction in contrast to all reported iron porphyrins, which can reduce CO2 in their Fe(0) state. Intermediates involved in CO2 reduction, Fe(III)-COOH and a Fe(II)-COOH, are identified with in situ FTIR-SEC and subsequently chemically generated and characterized using FTIR, resonance Raman, and M?ssbauer spectroscopy. The mechanism of the reaction helps elucidate a key role played by a closely placed proton transfer residue in aiding CO2 binding to Fe(I), stabilizing the intermediates, and determining the fate of a rate-determining Fe(II)-COOH intermediate.
The role of porphyrin peripheral substituents in determining the reactivities of ferrous nitrosyl species
Amanullah, Sk,Dey, Abhishek
, p. 5909 - 5921 (2020/07/13)
Ferrous nitrosyl {FeNO}7 species is an intermediate common to the catalytic cycles of Cd1NiR and CcNiR, two heme-based nitrite reductases (NiR), and its reactivity varies dramatically in these enzymes. The former reduces NO2- to NO in the denitrification pathway while the latter reduces NO2- to NH4+ in a dissimilatory nitrite reduction. With very similar electron transfer partners and heme based active sites, the origin of this difference in reactivity has remained unexplained. Differences in the structure of the heme d1 (Cd1NiR), which bears electron-withdrawing groups and has saturated pyrroles, relative to heme c (CcNiR) are often invoked to explain these reactivities. A series of iron porphyrinoids, designed to model the electron-withdrawing peripheral substitution as well as the saturation present in heme d1 in Cd1NiR, and their NO adducts were synthesized and their properties were investigated. The data clearly show that the presence of electron-withdrawing groups (EWGs) and saturated pyrroles together in a synthetic porphyrinoid (FeDEsC) weakens the Fe-NO bond in {FeNO}7 adducts along with decreasing the bond dissociation free energies (BDFENH) of the {FeHNO}8 species. The EWG raises the E° of the {FeNO}7/8 process, making the electron transfer (ET) facile, but decreases the pKa of {FeNO}8 species, making protonation (PT) difficult, while saturation has the opposite effect. The weakening of the Fe-NO bonding biases the {FeNO}7 species of FeDEsC for NO dissociation, as in Cd1NiR, which is otherwise set-up for a proton-coupled electron transfer (PCET) to form an {FeHNO}8 species eventually leading to its further reduction to NH4+.
Organic light-emitting compound and preparation method and application thereof
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Paragraph 0051-0055, (2020/10/29)
The invention discloses an organic light-emitting compound as well as a preparation method and application thereof. The organic light-emitting compound has a structural formula shown in the specification, wherein in the structural formula, R is C6-C12 alkyl. According to the preparation method, 2-alkylpyrrolo[3,4-c]pyrrole-1-3(2H, 5H)-diketone is taken as a main body, and chromophoric groups, indole, are respectively introduced into symmetrical positions on two sides of pyrrole, and thereby the organic light-emitting compound is finally obtained. The organic light-emitting compound has a light-emitting characteristic in an organic solvent, wherein the fluorescence intensity is further improved after anions are introduced into a system; the organic light-emitting compound can be applied tothe fields of light-emitting devices, laser dyes, fluorescence sensitivity, anti-counterfeiting technologies, fluorescence imaging, biomedical analysis and the like.
Evaluating the influence of heteroatoms on the electronic properties of aryl[3,4-c]pyrroledione based copolymers
Hale, Benjamin J.,Elshobaki, Moneim,Gebhardt, Ryan,Wheeler, David,Stoffer, Jon,Tomlinson, Aimée,Chaudhary, Sumit,Jeffries-EL, Malika
, p. 85 - 92 (2016/12/26)
A donor-acceptor-type conjugated copolymer (PBDT-PPD) composed of benzodithiophene (BDT) and pyrrolopyrroledione (PPD) was synthesized using the Stille cross-coupling reaction. Using both experimental and theoretical data, the optical, electrochemical, and photovoltaic properties of PBDT-PPD were compared with those of its sulfur analog, PBDT-TPD, which is composed of BDT and thienopyrroledione (TPD). The optical bandgaps of the polymers were determined to be 1.86 and 2.20 eV, respectively. While both materials possessed similar highest occupied molecular orbital (HOMO) levels, the lowest unoccupied molecular orbital (LUMO) level for PBDT-PPD was raised relative to that of PBDT-TPD. Devices incorporating PBDT-PPD had a higher open-circuit voltage and fill factor, yet drastically lower short-circuit current density (Jsc) than PBDT-TPD leading to a lower power conversion efficiency (PCE). The lack of significant intramolecular charge transfer (ICT) combined with the high LUMO of PBDT-PPD resulted in poor spectral overlap with the solar spectrum, lowering Jsc. Additionally, there was poor electron injection into PCBM, which also reduced the PCE.
Calix[4]tetrahydrothiophenopyrrole: A ditopic receptor displaying a split personality for ion recognition
Saha, Indrajit,Park, Kyung Hwa,Han, Mina,Kim, Sung Kuk,Lynch, Vincent M.,Sessler, Jonathan L.,Lee, Chang-Hee
, p. 5414 - 5417 (2015/02/19)
A calix[4]pyrrole fused with 2,5-dihydrothiophene, possessing both a deep, π-electron-rich pocket upon anion binding and chelating ligands on the periphery, was developed. The receptor selectively forms an ion-pair complex with CsF through H-bonding and a
A simple synthesis of 1-substituted diethyl pyrrole-3,4-dicarboxylates
Skrlep, Luka,Cercek-Hocevar, Andreja,Jakse, Renata,Stanovnik, Branko,Svete, Jurij
experimental part, p. 683 - 688 (2009/12/26)
A series of 1-substituted diethyl 1H-pyrrole-3,4-dicarboxylates 4a - o were prepared in 14-93% yield by acid-catalysed treatment of diethyl 2,3-bis[(E, E)-(dimethylamino)-methylidene]succinate (2) with various aliphatic and (hetero)aromatic primary amines 3a - o. The configuration of the C=C double bonds in the bis-enaminone 2 was determined by 1H NMR and HMBC spectroscopy.
New carboxylic acid amides of the pyrrole series: Synthetic routes and biological aspects
Walter, Harald
scheme or table, p. 351 - 362 (2009/01/31)
Complex II inhibitors play an important role in agrochemical fungicide research and have been known for more than 40 years. With the introduction of ortho-substituted heterocyclic amides, a breakthrough in activity level and spectrum within this class was achieved. In the meantime all major agrochemical companies have entered this field. In this paper, a special complex II subclass, the pyrrole carboxamides, will be introduced in more detail and the synthesis of selected compounds as well as a short biological SAR analysis of the pyrrole subclass will be discussed.
Diethoxymethyl protected pyrroles: Synthesis and regioselective transformations
Bergauer,Gmeiner
, p. 2281 - 2288 (2007/10/03)
Treatment of the acceptor-substituted pyrroles 1a-k with neat triethyl orthoformate gives access to the diethoxymethyl (DEM) protected derivatives 2a-k in high yield. Convenient and mild cleavage was achieved by subsequent treatment of the DEM-pyrroles 2a-k with trifluoroacetic acid in acetonitrile and aqueous NaOH at room temperature. DEM protection proved suitable for a variety of regioselective transformations involving directed orthometalation and iodine-magnesium exchange processes. Furthermore, electrophilic halogenations and Pd-catalyzed coupling reactions were also carried out.
