98-98-6Relevant articles and documents
Barbituric acid initiated rearrangement of 2,2'-pyridil into 5,5'-(2-pyrilidine)bisbarbituric acid.
Jursic, Branko S,Neumann, Donna M,Martin, Kenneth L,Stevens, Edwin D
, p. 811 - 813 (2002)
[reaction: see text] In the study of the barbituric acid initiated 2,2'-pyridil rearrangement, a very efficient synthetic procedure (isolated yield 80-90%) for the preparation of useful 2-pyrilidenes 3 was developed.
Copper(II)-Catalyzed Selective Para Amination of Arylamine with Pyrazole by C?H Functionalization
Xu, Jun,Du, Kui,Shen, Jiabin,Shen, Chao,Chai, Kejie,Zhang, Pengfei
, p. 3675 - 3679 (2018)
A coordinating activation strategy for selective para amination of arylamine with pyrazole is developed. Various substrates are compatible, giving the corresponding products in moderate to good yields. This strategy provides a practical solution for the efficient synthesis of arylamine-containing pharmacophores from simple starting materials. A single electron transfer mechanism is suggested for this reaction.
DNA-templated metal catalysis
Brunner, Jens,Mokhir, Andriy,Kraemer, Roland
, p. 12410 - 12411 (2003)
Hydrolysis of an ester substrate by a CuII complex catalyst, both attached to oligo-peptide nucleic acids (PNA), is accelerated up to 485-fold in the presence of a complementary DNA template. The approach combines the sequence selectivity of DNA-templated reactions with signal amplification by multiple turnover and the versatility of metal catalysis. Copyright
ANODIC OXIDATION OF 2-PICOLINE
Toomey, Joseph E.,Chaney, Gregory A.
, p. 697 - 704 (1991)
Concentrations, temperature, and current density for anodic oxidation of 2-picoline were optimized by using three statistically designed experiments.Criteria for optimization were chemical yield, current efficiency, space-time yield and rate of anode corrosion.
Detection of transient intermediates in the metal-dependent nonoxidative decarboxylation catalyzed by α-amino-β-carboxymuconate-ε- semialdehyde decarboxylase
Li, Tingfeng,Ma, John K.,Hosler, Jonathan P.,Davidson, Victor L.,Liu, Aimin
, p. 9278 - 9279 (2007)
The first description of a metalloenzyme-mediated nonoxidative decarboxylation reaction was that catalyzed by α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) (Li, T.; Walker, A. L.; Iwaki, H.; Hasegawa, Y.; Liu, A. J. Am. Chem. Soc. 2005, 127, 12282-12290 and Liu, A.; Zhang, H. Biochemistry 2006, 45, 10407-10411). Here, we report a rapid kinetic study of the ACMSD reaction using the cobalt(II)-reconstituted enzyme. Two previously undetected intermediates of the reaction are characterized. These are proposed to be the aminomuconate-ε-semialdehyde (AMS) product of the decarboxylation in complex with the enzyme and the free AMS after release from ACMSD. It was possible to determine the rates of formation of the enzyme-substrate complex (2.4 × 106 s-1 M-1), release of the AMS product (8.8 s-1), and spontaneous cyclization of AMS to picolinic acid (0.05 s-1), which is the final product of the reaction. Reconstructed spectra of these reaction intermediates and a kinetic mechanism for the overall reaction are presented. Copyright
Highly Selective Detection of Hypochlorous Acid by a Bis-heteroleptic Ru(II) Complex of Pyridyl-1,2,3-triazole Ligand via C(sp2)-H Hydroxylation
Sen, Bhaskar,Sheet, Sanjoy Kumar,Patra, Sumit Kumar,Koner, Debaprasad,Saha, Nirmalendu,Khatua, Snehadrinarayan
, p. 9982 - 9991 (2019)
A Ru(II) complex (Ru-1) of a substituted pyridyl-1,2,3-triazole ligand (BtPT) for highly selective "light-up" detection of hypochlorous acid is presented. An unusual anti-Markovnikov HOCl addition to the C=C bond of 1,2,3-triazole and a highly specific C(sp2)-H hydroxylation over epoxidation made Ru-1 a highly selective luminescent HOCl probe. The abnormal regio- and stereoselective HOCl addition and subsequent hydroxylation mechanism in detail is supported by the combination of ESI-MS, 1H/13C NMR spectroscopy, and 1H NMR titration. The hydroxylation at the C5 center in 1,2,3-triazole increases the electron density and makes BtPT a better σ-donor as well as π-donor, which in turn increases the 3MC-3MLCT energy gap and inhibits the nonradiative decay from the excited state of Ru-1 and is the key reason for luminescence light-up. Most importantly, the exogenous and endogenous HOCl imaging in the living HEK293T cells is also demonstrated. The probe showed low cytotoxicity and efficiently permeated the cell membrane. The cell-imaging experiments revealed rapid staining of the extranuclear region of HEK293T cells which clearly indicates the presence of cytoplasmic HOCl. The endogenous HOCl generation and imaging, stimulated by lipopolysaccharides (LPS) and paraquat in the HEK293T cells, is also demonstrated.
Use of bacteria for rapid, pH-neutral, hydrolysis of the model hydrophobic carboxylic acid ester p-nitrophenyl picolinate
Forest, Alexandra E.,Goldstine, Gordon G.,Murray, Sean R.,Schrodi, Yann
, p. 435 - 439,5 (2012)
Caulobacter crescentus, Escherichia coli and Bacillus subtilis cultures promote the hydrolysis of the model ester p-nitrophenyl picolinate (PNPP) at neutral pH with high efficiency. Hydrolysis is related to cell concentration, while the interaction of PNPP with both bacterial cells and their extracellular molecules is required for a maximum rate of PNPP hydrolysis in C. crescentus cultures. Furthermore, C. crescentus cultures hydrolyse PNPP at concentrations useful in synthetic chemistry.
Reaction Acceleration Promoted by Partial Solvation at the Gas/Solution Interface
Qiu, Lingqi,Wei, Zhenwei,Nie, Honggang,Cooks, R. Graham
, p. 1362 - 1365 (2021/09/14)
The kinetics of organic reactions of different types in microvolumes (droplets, thin films, and sealed tubes) show effects of gas/solution interfacial area, reaction molecularity and solvent polarity. Partial solvation at the gas/solution interface is a major contributor to the 104-fold reaction acceleration seen in bimolecular but not unimolecular reactions in microdroplets. Reaction acceleration can be used to manipulate selectivity by solvent choice.
{BW12O40} Hybrids Modified by in Situ Synthesized Rigid Ligand with Supercapacitance and Photocatalytic Properties
Du, Nana,Gong, Lige,Wang, Chunmei,Wang, Chunxiao,Yu, Kai,Zhang, Wenjia,Zhou, Baibin
supporting information, p. 16357 - 16369 (2021/11/13)
Organic rigid ligand-modified polyoxometalate-based materials possess complex and diverse structures, promising electrochemical energy storage properties and outstanding photocatalytic capabilities. Hence, two new [BW12O40]5-(abbreviated as {BW12O40})-based inorganic-organic hybrids [{Cu(en)2(H2O)}][{Cu(pdc)(en)}{Cu(en)2}(BW12O40)]·2H2O (1) and [{CuI5(pz)6(H2O)4}(BW12O40)] (2) (pdc = 2-picolinate, en = ethylenediamine, pz = pyrazine) were successfully synthesized through a hydrothermal method. Among them, pdc and pz were obtained by in situ transformation from 2,6-pyridinedicarboxylic acid (H2 pydc) and 2,3-pyrazinedicarboxylic acid (H2pzdc), respectively. In compound 1, the {BW12O40} clusters as an intermediate junction connect with {Cu(pdc)(en)}{Cu(en)2} and {Cu(en)2(H2O)} to form monomers, which in turn form supramolecular chains, sheets, and space network via hydrogen bonding. The {BW12O40} clusters are packed into copper-pyrazine frameworks in compound 2, and a unique polyoxometalate-based metal organic frameworks (POMOFs) structure with a new topology of {12}2{6.123.142}2{62.12.142.18}{62.123.16}{6}6 is formed via covalent bonds. When used as electrode materials for supercapacitors, the values of specific capacitance are 651.56 F g-1 for 1-GCE and 584.43 F g-1 for 2-GCE at a current density of 2.16 A g-1 and good cycling stability (90.94%, 94.81% of the initial capacity after 5000 cycles at 15.12 A g-1, respectively). The kinetic analysis reveals that surface capacitance plays a major role. Furthermore, both compounds can effectively degrade Rhodamine B (RhB) and Methylene blue (MB), showing the outstanding photocatalytic performance.
Reactivity of secondary N-alkyl acrylamides in Morita–Baylis–Hillman reactions
Ahmar, Mohammed,Queneau, Yves,Verrier, Charlie,Yue, Xiaoyang
, p. 319 - 330 (2021/10/29)
The Morita–Baylis–Hillman (MBH) reaction of secondary N-alkyl acrylamides, discarded up to now from investigations of the scope of activated alkenes, was studied. Optimization of the reaction conditions revealed that a balance must be found between activation of the MBH coupling reaction and that of the undesired competitive aldehyde Cannizzaro reaction. Using 3-Hydroxyquinuclidine (3-HQD) in a 1:1 water-2-MeTHF mixture provides the appropriate conditions that were applicable to a wide range of diversely substituted secondary N-alkyl acrylamides and aromatic aldehydes, giving rise to novel amide-containing MBH adducts under mild and clean conditions.
