4277-63-8Relevant academic research and scientific papers
Anion exchange: A novel way of preparing hierarchical porous structure in poly(ionic liquid)s
Qin, Li,Wang, Binshen,Zhang, Yongya,Chen, Li,Gao, Guohua
, p. 3785 - 3788 (2017)
Hierarchical porous poly(ionic liquid)s (PILs) with high specific surface area were firstly synthesized via anion exchange. The exchange of bulky salicylate and its dimers/clusters in PILs by other smaller anions increased the specific surface area and fabricated a hierarchical porous structure. The high specific surface area and hierarchical porous structure prompted a high degree of exposure of the active sites and made the heterogeneous PIL catalysts contact with substrates sufficiently, enhancing their catalytic activity.
Changes in Regioselectivity of H Atom Abstraction during the Hydroxylation and Cyclization Reactions Catalyzed by Hyoscyamine 6β-Hydroxylase
Ushimaru, Richiro,Ruszczycky, Mark W.,Liu, Hung-Wen
supporting information, p. 1062 - 1066 (2019/01/23)
Hyoscyamine 6β-hydroxylase (H6H) is an αKG-dependent nonheme iron oxidase that catalyzes the oxidation of hyoscyamine to scopolamine via two separate reactions: hydroxylation followed by oxidative cyclization. Both of these reactions are expected to involve H atom abstraction from each of two adjacent carbon centers (C6 vs C7) in the substrate. During hydroxylation, there is a roughly 85:1 preference for H atom abstraction from C6 versus C7; however, this inverts to a 1:16 preference during cyclization. Furthermore, 18O incorporation experiments in the presence of deuterated substrate are consistent with the catalytic iron(IV)-oxo complex being able to support the coordination of an additional ligand during hydroxylation. These observations suggest that subtle differences in the substrate binding configuration can have significant consequences for the catalytic cycle of H6H.
Solventless selective phosgene-free N-carbonylation of N-heteroaromatics (pyrrole, indole, carbazole) under mild conditions
Carafa, Marianna,Iannone, Francesco,Mele, Valentina,Quaranta, Eugenio
, p. 3377 - 3385 (2013/01/16)
N-Heteroaromatics HetNH, such as pyrrole (1), indole (2) and carbazole (3), have been selectively N-carbonylated by a direct reaction with diphenyl carbonate (DPC), used as an environmental friendly carbonyl active species in place of toxic and hazardous phosgene. The carbonylation reaction can be effectively catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), which can act as a base catalyst by activating the HetNH substrate, and as a nucleophile catalyst by activating the organic carbonate. The influence of reaction parameters (temperature, reaction time, DBU load, DPC/HetNH molar ratio) on the productivity of the process has been also investigated. The synthetic methodology does not require severe temperature conditions, is solventless, simple (only one step), efficient and selective, and offers a new solution to the synthesis of synthetically versatile HetNCO2Ph derivatives through a route alternative to the current traditional phosgenation methods.
Green N-methylation of electron deficient pyrroles with dimethylcarbonate
Laurila, Michael L.,Magnus, Nicholas A.,Staszak, Michael A.
experimental part, p. 1199 - 1201 (2010/04/22)
The N-methylation of electron-deficient pyrroles was affected using dimethyl carbonate in the presence of DMF and catalytic DABCO. This alkylation methodology has proven useful for the alkylation of a variety of pyrroles in 72-98% yields and is considered to be green chemistry relative to the more common use of methyl halides or dimethyl sulfate.
Superbase-promoted direct N-carbonylation of pyrrole with carbonic acid diesters
Carafa, Marianna,Distaso, Monica,Mele, Valentina,Trani, Francesca,Quaranta, Eugenio
, p. 3691 - 3696 (2008/09/20)
Carbonic acid diesters have been investigated as carbonylating agents in the direct reaction with pyrrole (HetNH). In the presence of superbases (DBU, P1-t-Bu, BTPP) as catalysts, the heteroaromatic substrate can be N-carbonylated by direct reaction with carbonic acid diesters under not-severe experimental conditions. The carbonylation reaction makes accessible pyrrole N-carbonyl derivatives (HetNC(O)OR, (HetN)2CO) selectively through a simple straightforward way, which offers a safe eco-friendly alternative to the traditional synthetic methods based on hazardous phosgene or phosgene-derivatives.
N-methylation of nitrogen-containing heterocycles with dimethyl carbonate
Ouk, Samedy,Thiebaud, Sophie,Borredon, Elisabeth,Chabaud, Bernard
, p. 3021 - 3026 (2007/10/03)
Reactivity of dimethyl carbonate, the environmentally friendly reagent, as methylating agent for nitrogen-containing heterocyclic compounds has been studied. Reactions of imidazole, pyrazole, pyrrole, morpholine, and piperazine with dimethyl carbonate to afford N-methylated products were reported. The reactions were carried out with neither catalyst nor solvent at a temperature range of 110-170°C under atmospheric pressure. Copyright Taylor & Francis, Inc.
7-azabicyclo[2.2.1]-heptane and -heptene derivatives as cholinergic receptor ligands
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, (2008/06/13)
7-Azabicyclo[2.2.1]-heptane and -heptene derivatives are disclosed that can be administered to a mammal, including a human, to treat disorders associated with a decrease or increase in cholinergic activity.
Synthesis of Highly Functionalized 7-Azabicycloheptadienes
Chen, Zhengming,Trudell, Mark L.
, p. 9649 - 9652 (2007/10/02)
Highly functionalized 7-azabicycloheptadiene derivatives have been synthesized via a cycloaddition reaction between N-acyl-3,4-disubstituted pyrroles and ethynyl p-tolyl sulfone 5.
BASE-CATALYZED HYDROLYSIS OF CARBAMATES. REMARKABLE REACTIVITY OF SEVERAL AZOLE DERIVATIVES
Germani, Raimondo,Pizzo, Ferdinando,Savelli, Gianfranco,Ponti, Pier Paolo
, p. 205 - 208 (2007/10/02)
The presence of an azole group (pyrrole, indole, carbazole) in carbamate derivatives determines a remarkable increase in reactivity in basic hydrolysis; these compounds undergo hydrolysis up to 35,000 times faster than the corresponding methylamino derivatives.Mechanism and rationale for such behaviour are discussed.
