31708-14-2Relevant academic research and scientific papers
Solvent Free Synthesis of N-Substituted Pyrroles Catalyzed by Calcium Nitrate
Wani, Rucha R.,Chaudhari, Hemchandra K.,Takale, Balaram S.
supporting information, p. 1337 - 1340 (2019/02/05)
Moderated and mild way for synthesizing N-substituted pyrrole has been demonstrated herein. No solvents need to be used for this reaction, and instead, reactants themselves acted as a reaction medium. In fact, the reaction is carried out using catalytic amount of Ca(NO3)2.4H2O. The reaction conditions are selective and mild that helped to tolerate a wide variety of functional groups to give the desired products in good chemical yields.
Sustainable Manganese-Catalyzed Solvent-Free Synthesis of Pyrroles from 1,4-Diols and Primary Amines
Borghs, Jannik C.,Lebedev, Yury,Rueping, Magnus,El-Sepelgy, Osama
supporting information, p. 70 - 74 (2019/01/11)
A general and selective metal-catalyzed conversion of biomass-derived primary diols and amines to the highly valuable 2,5-unsubstituted pyrroles has been developed. The reaction is catalyzed by a stable nonprecious manganese complex (1 mol %) in the absence of organic solvents whereby water and molecular hydrogen are the only side products. The manganese catalyst shows unprecedented selectivity, avoiding the formation of pyrrolidines, cyclic imides, and lactones.
Synthesis method for converting lignin 4-O-5 model compound diaryl ether into nitrogen-containing compound
-
Paragraph 0048-0050, (2019/04/26)
The invention discloses a synthesis method for converting lignin 4-O-5 model compound diaryl ether into a nitrogen-containing compound. According to the synthesis method, a diaryl ether compound andan amine compound are subjected to a heating reaction in a certain amount of a solvent (containing a certain amount of water) in an argon atmosphere (containing a certain amount of air) under the actions of a metal catalyst and sodium borohydride, such that the drug with the important physiological activity or the compound with the natural product skeleton containing nitrogen is formed by directlycoupling the C-O bond cut and the amine compound cross while the corresponding aromatic hydrocarbon is obtained. According to the present invention, the synthesis method has characteristics of simpleand easily-available raw materials, high conversion rate, important product and good yield, and has broad application prospects in the degradation and deep development and utilization of lignin.
Solvent Free Synthesis of N-Substituted Pyrrole Derivatives Catalyzed by Silica Sulfuric Acid
Khammas,Yolacan,Aydogan
, p. 2680 - 2683 (2019/04/04)
Sulfuric acid immobilized on silica gel is used as an efficient catalyst in the synthesis of N-substituted pyrrole derivatives by the Clauson–Kaas pyrrole synthesis. The solvent free reaction mixture is stirred by grinding. Within very short reaction time the process leads to the corresponding products without any decomposition recorded.
Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-O-5 Linkage in Lignin Models
Zeng, Huiying,Cao, Dawei,Qiu, Zihang,Li, Chao-Jun
, p. 3752 - 3757 (2018/03/13)
Lignin is the second most abundant organic matter on Earth, and is an underutilized renewable source for valuable aromatic chemicals. For future sustainable production of aromatic compounds, it is highly desirable to convert lignin into value-added platform chemicals instead of using fossil-based resources. Lignins are aromatic polymers linked by three types of ether bonds (α-O-4, β-O-4, and 4-O-5 linkages) and other C?C bonds. Among the ether bonds, the bond dissociation energy of the 4-O-5 linkage is the highest and the most challenging to cleave. To date, 4-O-5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross-coupling of diaryl ether 4-O-5 linkage models with amines is reported, in which dual C(Ar)?O bond cleavages form valuable nitrogen-containing derivatives.
Formal aromaticity transfer for palladium-catalyzed coupling between phenols and pyrrolidines/indolines
Qiu, Zihang,Li, Jiang-Sheng,Li, Chao-Jun
, p. 6954 - 6958 (2017/10/05)
We herein describe a palladium-catalyzed formal aromaticity transfer coupling reaction between phenols and pyrrolidines or indolines to generate the corresponding N-cyclohexyl pyrroles or indoles. In this transformation, the aromaticity of phenols is formally passed on to the pyrrolidine or indoline units. Substituted phenols thus can serve as latent cyclohexyl equivalents for the fast construction of various N-cyclohexyl pyrroles and indoles.
Unveiling the Biocatalytic Aromatizing Activity of Monoamine Oxidases MAO-N and 6-HDNO: Development of Chemoenzymatic Cascades for the Synthesis of Pyrroles
Scalacci, Nicoló,Black, Gary W.,Mattedi, Giulio,Brown, Nicola L.,Turner, Nicholas J.,Castagnolo, Daniele
, p. 1295 - 1300 (2017/08/09)
A chemoenzymatic cascade process for the sustainable production of pyrroles has been developed. Pyrroles were synthesized by exploiting the previously unexplored aromatizing activity of monoamine oxidase enzymes (MAO-N and 6-HDNO). MAO-N/6-HDNO whole cell biocatalysts are able to convert 3-pyrrolines into pyrroles under mild conditions and in high yields. Moreover, MAO-N can work in combination with the ruthenium Grubbs catalyst, leading to the synthesis of pyrroles from diallylamines/-anilines in a one-pot cascade metathesis-aromatization sequence.
Copper-Catalyzed Oxidative Dehydrogenative C(sp3)?H Bond Amination of (Cyclo)Alkanes using NH-Heterocycles as Amine Sources
Wang, Chang-Sheng,Wu, Xiao-Feng,Dixneuf, Pierre H.,Soulé, Jean-Fran?ois
, p. 3075 - 3082 (2017/08/18)
A copper-catalyzed oxidative C(sp3)?H/N?H coupling of NH-heterocycles with affordable (cyclo)alkanes has been developed. This procedure involves C(sp3)?N bond formation through a radical pathway generated by homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalysts. The reaction tolerates a series of functional groups, such as bromo, fluoro, ester, ketone, nitrile, methyl, and methoxy. free-NH-containing indoles, pyrroles, pyrazoles, indazoles, and benzotriazoles are successfully N-alkylated.
Discovery of allosteric and selective inhibitors of inorganic pyrophosphatase from mycobacterium tuberculosis
Pang, Allan H.,Garzan, Atefeh,Larsen, Martha J.,McQuade, Thomas J.,Garneau-Tsodikova, Sylvie,Tsodikov, Oleg V.
, p. 3084 - 3092 (2016/11/29)
Inorganic pyrophosphatase (PPiase) is an essential enzyme that hydrolyzes inorganic pyrophosphate (PPi), driving numerous metabolic processes. We report a discovery of an allosteric inhibitor (2,4-bis(aziridin-1-yl)-6-(1-phenylpyrrol-2-yl)-s-triazine) of bacterial PPiases. Analogues of this lead compound were synthesized to target specifically Mycobacterium tuberculosis (Mtb) PPiase (MtPPiase). The best analogue (compound 16) with a Ki of 11 μM for MtPPiase is a species-specific inhibitor. Crystal structures of MtPPiase in complex with the lead compound and one of its analogues (compound 6) demonstrate that the inhibitors bind in a nonconserved interface between monomers of the hexameric MtPPiase in a yet unprecedented pairwise manner, while the remote conserved active site of the enzyme is occupied by a bound PPi substrate. Consistent with the structural studies, the kinetic analysis of the most potent inhibitor has indicated that it functions uncompetitively, by binding to the enzyme-substrate complex. The inhibitors appear to allosterically lock the active site in a closed state causing its dysfunctionalization and blocking the hydrolysis. These inhibitors are the first examples of allosteric, species-selective inhibitors of PPiases, serving as a proof-of-principle that PPiases can be selectively targeted.
Sustainable Pathways to Pyrroles through Iron-Catalyzed N-Heterocyclization from Unsaturated Diols and Primary Amines
Yan, Tao,Barta, Katalin
, p. 2321 - 2325 (2016/10/24)
Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom-economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily available alcohol substrates have been recently established; however, these approaches rely on the use of noble metals such as ruthenium or iridium. Here, we report on the direct synthesis of pyrroles using a catalyst based on the earth-abundant and inexpensive iron. The method uses 2-butyne-1,4-diol or 2-butene-1,4-diol that can be directly coupled with anilines, benzyl amines, and aliphatic amines to obtain a variety of N-substituted pyrroles in moderate-to-excellent isolated yields.
