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110-85-0Relevant articles and documents
Axial ligation of iron(III) porphyrin with a series of aliphatic bases: Piperazine, piperidine and pyrrolidine
Saffari,Khorasani-Motlagh,Noroozifar
, p. 128 - 132 (2012)
The binding of a series of nitrogen donor ligands (Piperazine (Pipz), Piperidine (Pip) and Pyrro- lidine (Pyr)) to iron porphyrin, OEPFeClO 4, where OEP is octaethylporphyrin, has been characterized by electronic spectroscopy in CH2Cl2. In nonaqueous media, in the presence of a neutral ligand, the equilibria observed are: OEPFeClO 4 + 2L [OEPFeL2]+ (β2) where the product is an ion pair and in some cases: OEPFeClO4 + L OEPFeLClO4 (K1), where the product may either be the six-coordinate or the five-coordinate [OEPFeL]+ ion pair, that L denotes neutral N-donor ligands. This behavior for the nitrogen donor ligands (L = Pipz, Pip, Pyr) is confirmed by spectrophotometric titrations data and the bind- ing constants for the substitution reaction have been reported. Pleiades Publishing, Ltd., 2012.
Putrescine Transaminases for the Synthesis of Saturated Nitrogen Heterocycles from Polyamines
Slabu, Iustina,Galman, James L.,Weise, Nicholas J.,Lloyd, Richard C.,Turner, Nicholas J.
, p. 1038 - 1042 (2016)
Putrescine transaminase (pATA; EC 2.6.1.82) catalyzes the transfer of an amino group from terminal diamine donor molecules to keto acid acceptors by using pyridoxal-5′-phosphate as a cofactor. The ygjG genes from Escherichia coli K12, Bacillus megaterium, and Bacillus mycoides were successfully cloned and expressed in E. coli BL21(DE3) cells. The three putrescine transaminases were all shown to prefer diaminoalkanes as substrates and thereby generated cyclic imines from the ω-amino aldehyde intermediates. The addition of a mild chemical reducing agent rapidly reduced the imine intermediate in situ to furnish a range of N-heterocycle products. We applied pATA in a biomimetic synthesis of 2,3-dihydro-1H-indolizinium-containing targets, notably the bioactive alkaloid ficuseptine.
Cobalt-bridged secondary building units in a titanium metal-organic framework catalyze cascade reduction of N-heteroarenes
Feng, Xuanyu,Song, Yang,Chen, Justin S.,Li, Zhe,Chen, Emily Y.,Kaufmann, Michael,Wang, Cheng,Lin, Wenbin
, p. 2193 - 2198 (2019)
We report here a novel Ti3-BPDC metal-organic framework (MOF) constructed from biphenyl-4,4′-dicarboxylate (BPDC) linkers and Ti3(OH)2 secondary building units (SBUs) with permanent porosity and large 1D channels. Ti-OH groups from neighboring SBUs point toward each other with an O-O distance of 2 ?, and upon deprotonation, act as the first bidentate SBU-based ligands to support CoII-hydride species for effective cascade reduction of N-heteroarenes (such as pyridines and quinolines) via sequential dearomative hydroboration and hydrogenation, affording piperidine and 1,2,3,4-tetrahydroquinoline derivatives with excellent activity (turnover number ～ 1980) and chemoselectivity.
Chemical equilibrium constants for the formation of carbamates in (carbon dioxide + piperazine + water) from 1H-NMR-spectroscopy
Ermatchkov, Viktor,Perez-Salado Kamps, Alvaro,Maurer, Gerd
, p. 1277 - 1289 (2003)
H-NMR spectroscopic investigations were performed on aqueous solutions of carbon dioxide and piperazine at temperatures ranging from 283 to 333K. These investigations were performed to determine quantitatively the speciation in these solutions. The results were used to determine the chemical equilibrium constants for the formation of piperazine carbamate, piperazine dicarbamate and protonated piperazine carbamate.
Intermolecular condensation of ethylenediamine to 1,4-diazabicyclo[2,2,2]octane over TS-1 catalysts
Wang, Yong,Liu, Yueming,Li, Xiaohong,Wu, Haihong,He, Mingyuan,Wu, Peng
, p. 258 - 267 (2009)
The intermolecular condensation of ethylenediamine (EDA) to 1,4-diazabicyclo[2.2.2]octane or triethylenediamine (TEDA) has been carried out over various titanosilicate catalysts. Superior to Ti-MWW, Ti-Beta, Ti-FER, and Ti-MOR, TS-1 showed higher EDA conversion and TEDA selectivity. The effects of reaction parameters, Ti content, and crystal size on the EDA condensation over TS-1 have been investigated. The mechanism for the TS-1-catalyzed condensation of EDA has also been considered. The acid sites, originated from the Si-OH groups adjacent to the "open" Ti sites, were assumed to contribute to the intermolecular condensation of EDA, whereas the Lewis acid sites directly related to Ti(IV) ions were not the true active sites. The primary intermolecular condensation of EDA to 1,4-diazacyclohexane or piperazine (PIP) took place mainly inside the micropores of the MFI structure, while the secondary condensation of PIP with EDA to TEDA was favored by the acid sites located near the pore entrance and on the outer surface of crystals.
Intermolecular condensation of ethylenediamine to 1,4-diazabicyclo(2,2,2)octane over H-ZSM-5 catalysts: Effects of Si/Al ratio and crystal size
Wang, Yong,Guo, Lifang,Ling, Yun,Liu, Yueming,Li, Xiaohong,Wu, Haihong,Wu, Peng
, p. 45 - 53 (2010)
The intermolecular condensation of ethylenediamine (EDA) to 1,4-diazabicyclo [2.2.2] octane (DABCO) or triethylenediamine (TEDA) was conducted over H-ZSM-5 catalysts. The effects of reaction parameters, Al content and crystal size on the EDA condensation over H-ZSM-5 have been investigated. The H-ZSM-5 catalyst with a medium Al content (Si/Al = 110) and a small crystal size (ca. 100 nm) showed 99% EDA conversion and afforded a TEDA yield as high as 74% under optimized conditions. The mechanism for the H-ZSM-5-catalyzed condensation of EDA has also been considered. The framework Al-related Br?nsted acid sites were assumed to contribute to selective intermolecular condensation of EDA to TEDA. The primary intermolecular condensation of EDA to piperazine (PIP) took place mainly inside the micropores of the MFI structure, while the secondary condensation of PIP with EDA to TEDA was favored by the acid sites located near the pore entrance and on the external surfaces of crystals.
Gas-phase pyrolysis in organic synthesis: A route for synthesis of cyanamides
Al-Awadi, Nouria A.,Abdelkhalik, Mervat Mohammed,El-Dusouqui, Osman M. E.,Elnagdia, Mohammad H.
, p. 207 - 209 (2010)
(Chemical Equation Presented) Pyrolysis of 1,7-di-[(E)-1- morpholinomethylidene]- and 1,7-di-[(E)-1-piperidino-methylidene]-4,6,10,12- tetramethylamino-2,8-dioxo-1,7-diaza-3,5,9,11-cyclododecatetraene-3, 9-dicarbonitrile 6a,b afforded pyridone 10 in addition to cyanamides 11a,b. On the other hand, pyrolysis of 1-[E-(4-(E-3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)- ylimino) methylpiperazin-1-yl] methylenamino-4,6-dimethyl-2-oxo-1,2- dihydropyridine-3-carbonitrile 8 gave 1-amino-4,6-dimethyl-2-oxo-1,2- dihydropyridine-3-carbonitrile 13 as well as piperazine. The mechanism of pyrolysis and the effect of stereochemistry of pyrolyzed substrates on the nature of the pyrolysates are discussed.
Facile hydrogenation of N-heteroarenes by magnetic nanoparticle-supported sub-nanometric Rh catalysts in aqueous medium
Nasiruzzaman Shaikh,Aziz, Md. Abdul,Kalanthoden, Abdul Nasar,Helal, Aasif,Hakeem, Abbas S.,Bououdina, Mohamed
, p. 4709 - 4717 (2018)
The hydrogenation of nitrogen-containing heterocyclic precursors in aqueous medium at low temperature without imposing molecular hydrogen pressure is quite challenging. Herein, we report the synthesis and performance of a novel catalyst capable of facile hydrogenation (employing tetrahydroxydiboron (THDB) as the reductant) of N-heteroarenes in water at 80 °C with good recyclability. Rhodium particles in the sub-nano range (3O4), using aqueous ammonia as a reducing agent at 50 °C. HRTEM and elemental mapping images reveal a homogeneous distribution of 3O4 nanoparticles having an average size within a narrow range of 7-9 nm. The superparamagnetic nature of the composite was confirmed by VSM analysis. The Rh@Fe3O4 catalyst was found to be highly efficient in the heterogeneous hydrogenation of nitrogen-containing heterocyclic compounds with quantitative conversion. It showed selectivity towards the hydrogenation of 1,2,3,4-tetrahydroquinoline (py-THQ) in water using THDB with a high TOF of 1632 h-1. These results are compared with the conversion and selectivity data obtained from reduction with molecular hydrogen gas pressure. The catalytic activity is extended to the successful hydrogenation of simple aromatics like benzene, toluene etc. Isotopic labelling studies were performed to determine the source of hydrogen in quinoline hydrogenation in the presence of THDB. It was found that it could be used for 16 consecutive cycles with gaseous hydrogen, without any undesired by-products; it also retained its original crystallinity.
Reactivity of borohydride incorporated in coordination polymers toward carbon dioxide
Kadota, Kentaro,Sivaniah, Easan,Horike, Satoshi
, p. 5111 - 5114 (2020)
Borohydride (BH4-)-containing coordination polymers converted CO2into HCO2-or [BH3(OCHO)]-, whose reaction routes were affected by the electronegativity of metal ions and the coo
Magnesium borohydride confined in a metal-organic framework: A preorganized system for facile arene hydroboration
Ingleson, Michael J.,Barrio, Jorge Perez,Bacsa, John,Steiner, Alexander,Darling, George R.,Jones, James T. A.,Khimyak, Yaroslav Z.,Rosseinsky, Matthew J.
, p. 2012 - 2016 (2009)
(Chemical Equation Presented) In close quarters: When confined in a metal-organic framework, magnesium borohydride reacts with arenes by a hydroboration pathway (see scheme), in contrast to its reactivity under analogous homogeneous solution-phase conditi
