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heterocyclic amines

Moritz Balkenhohl, Cyril François, Daniela Sustac Roman, Pauline Quinio, Paul Knochel
A new transition-metal-free amination of pyridine-2-sulfonyl chloride and related N-heterocycles using magnesium amides of type R2NMgCl·LiCl is reported. Additionally, the directed ortho-magnesiation of pyridine-2-sulfonamides using TMPMgCl·LiCl was investigated. Reaction of the magnesium intermediates with various electrophiles and subsequent amination using magnesium amides led to a range of 2,3-functionalized pyridines. Also, cyclization reactions providing an aza-indole and an aza-carbazole were carried out...
January 17, 2017: Organic Letters
Tristram Chivers, Risto S Laitinen
Cyclocondensation is a major preparative route for the generation of inorganic heterocycles especially in the case of ring systems involving a Group 15 or 16 element linked to nitrogen. This Perspective will consider recent experimental and computational studies involving the reactions of primary amines (or their synthetic equivalents) with pnictogen and chalcogen halides. The major focus will be a discussion of the identity and role of acyclic intermediates in the reaction pathways to ring formation, as well as the nature of the heterocycles so formed...
January 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Anton Vladimirovich Lukashenko, Vitaly Aleksandrovich Osyanin, Dmitry Vladimirovich Osipov, Yuri N Klimochkin
A simple and efficient method for the synthesis of 4H-chromenes and 1H-benzo[f]chromenes containing trifluoroacetyl or aroyl group in pyran ring from o-quinone methide precursors and push-pull enaminoketones has been developed. The chromenes are presumably formed through an initial oxa-Diels-Alder reaction followed by an elimination of amine. Possibility of further transformations of given chromenes to o-hydroxybenzylated pyrazoles, isoxazoles and pyridines has been demonstrated.
January 16, 2017: Journal of Organic Chemistry
Lívia Queiroz de Sousa, Kátia da Conceição Machado, Samara Ferreira de Carvalho Oliveira, Lidiane da Silva Araújo, Evaldo Dos Santos Monção-Filho, Ana Amélia de Carvalho Melo-Cavalcante, Gerardo Magela Vieira-Júnior, Paulo Michel Pinheiro Ferreira
Amphibians present pharmacologically active aliphatic, aromatic and heterocyclic molecules in their skin as defense against microorganisms, predators and infections, such as steroids, alkaloids, biogenic amines, guanidine derivatives, proteins and peptides. Based on the discovered bioactive potential of bufadienolides, this work reviewed the contribution of amphibians, especially from members of Bufonidae family, as source of new cytotoxic and antitumor molecules, highlighting the mechanisms responsible for such amazing biological potentialities...
January 6, 2017: Toxicon: Official Journal of the International Society on Toxinology
Dan Zhang, Wenhao Hu
Metal carbenes derived from transition metal-catalyzed decomposition of diazo compounds react with nucleophiles with heteroatoms, such as alcohols and amines, to generate highly active oxonium/ammonium ylides intermediates. These intermediates can be trapped by appropriate electrophiles to provide three-component products. Based on this novel trapping process, we have developed novel multicomponent reactions (MCRs) of diazo compounds, alcohols/anilines, and electrophiles. The nucleophiles were also extended to electron-rich heterocycles (indoles and pyrroles)/arenes, in which the resulting zwitterionic intermediates were also trapped by electrophiles...
January 4, 2017: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Robert H Crabtree
The different types of acceptorless alcohol dehydrogenation (AAD) reactions are discussed, followed by the catalysts and mechanisms involved. Special emphasis is put on the common appearance in AAD of pincer ligands, of noninnocent ligands, and of outer sphere mechanisms. Early work emphasized precious metals, mainly Ru and Ir, but interest in nonprecious metal AAD catalysis is growing. Alcohol-amine combinations are discussed to the extent that net oxidation occurs by loss of H2. These reactions are of potential synthetic interest because they can lead to N heterocycles such as pyrroles and pyridines...
January 4, 2017: Chemical Reviews
Maher Abd El-Aziz El-Hashash, Sobhi Mohamed Gomha, Elham Ezz El-Arab
A series of pyrazolyl-triazolo[1,5-a]pyrimidines, pyrazolyl-tetrazolo[1,5-a]pyrimidines, pyrazolyl-benzo[4,5]imidazo[1,2-a]pyrimidines and bis-azolopyrimidines were prepared by reaction of pyrazolyl-chalcones or its bis-pyrazolyl-chalcones with the appropriate heterocyclic amines as aminotriazole, aminotetrazole, 2-aminobenzimidazole and 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-amine by grinding method. The newly synthesized compounds have been characterized on the basis of elemental analysis and spectral data (IR, (1)H- and (13)C-NMR, Mass)...
2017: Chemical & Pharmaceutical Bulletin
Lili He, Zhongqi Xu, Takeshi Hirokawa, Li Shen
Biogenic amines (BAs) play significant roles in indicating human health or food quality. Aiming to simultaneously determine three structures (aliphatic, aromatic and heterocyclic) of underivatized BAs, we explored a simple and rapid capillary electrophoresis (CE) method only coupled with conventional UV detector for the separation of thirteen key BAs. The strategy is to choose a UV absorbing probe as co-ion in the background electrolyte (BGE), and different BAs could be characterized by positive or negative peaks according to the fact that their UV absorptivity coefficients at a certain wavelength are better or worse than that of the UV absorbing probe...
December 24, 2016: Journal of Chromatography. A
Lucien D Caspers, Peter Finkbeiner, Boris J Nachtsheim
Unprotected aromatic amines can be used as directing groups in metal-catalyzed C-H alkynylations of alkenes. Using low amounts of an Ir(III)-catalyst in combination with alkynylbenziodoxolones as electrophilic alkyne transfer reagents, highly desirable 1,3-enynes were isolated in excellent yields of up to 98% and Z-stereoselectivity. A broad substrate scope as well as the high synthetic utility of the 1,3-enynes renders this novel method an efficient approach for the synthesis of 5- and 6-membered heterocycles...
December 31, 2016: Chemistry: a European Journal
Bohdan Ardan, Vasyl Kinzhybalo, Yurii Slyvka, Olga Shyyka, Mykhaylo Luk Yanov, Tadeusz Lis, Marian Mys Kiv
As an important class of heterocyclic compounds, 1,3,4-thiadiazoles have a broad range of potential applications in medicine, agriculture and materials chemistry, and were found to be excellent precursors for the crystal engineering of organometallic materials. The coordinating behaviour of allyl derivatives of 1,3,4-thiadiazoles with respect to transition metal ions has been little studied. Five new crystalline copper(I) π-complexes have been obtained by means of an alternating current electrochemical technique and have been characterized by single-crystal X-ray diffraction and IR spectroscopy...
January 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Abbas Ahmadi, Mohsen Khalili, Zahra Olama, Shirin Karami, Babak Nahri-Niknafs
Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs worldwide and represent a mainstay in the therapy of acute and chronic pain and inflammation. The traditional NSAIDs like ibuprofen (I) contain free carboxylic acid group which can produce gastro-intestinal (GI) damage in long-term using of them. In order to obtain the novel NSAIDs with less side effects; carboxylic acid moiety has been modified into various amide groups which is the most active area of research in this family...
December 26, 2016: Mini Reviews in Medicinal Chemistry
Jayalakshmi Sridhar, Jiawang Liu, Rajesh Komati, Richard Schroeder, Quan Jiang, Phan Tram, Kevin Riley, Maryam Foroozesh
Members of the cytochrome P450 1A family metabolize many procarcinogens such as polycyclic aromatic hydrocarbons and heterocyclic amines. Inactivation of these enzymes is prerequisite for cancer prevention and treatment in certain cases. Mechanism-based inhibition (time and co-factor dependent) is an effective method for the inactivation of these enzymes. Our recent study on emodin analogs revealed an anthraquinone with ortho-methylarylamine moiety that exhibited time-dependent inhibition of P450 enzymes 1A1 and 1A2...
December 20, 2016: Drug Metabolism Letters
Ramon Borges da Silva, Rodolfo Inêz Teixeira, James L Wardell, Solange M S V Wardell, Simon J Garden
In the present study a series of N-phenyl-1,10-phenanthroline-2-amine derivatives were obtained by heating 2-chlorophenanthroline with aniline derivatives under solvent free conditions in good to excellent yields. The N-phenyl-1,10-phenanthroline-2-amines were employed as substrates in a copper(ii)-catalyzed C-H amination reaction to give derivatives of the novel heterocyclic system benzo[4,5]imidazo[1,2-a][1,10]phenanthroline. The structure of these compounds was predicted to be helical by DFT calculations and single crystal X-ray diffraction of an example of this system confirmed the non-planar helical structure...
December 19, 2016: Organic & Biomolecular Chemistry
Yi Wang, Peter W Villalta, Lijuan Peng, Karen Dingley, Michael A Malfatti, K W Turteltaub, Robert J Turesky
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed during the high-temperature cooking of meats. The cytochrome P450-mediated N-hydroxylation of the exocyclic amine group of PhIP produces 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine, an electrophilic metabolite that forms adducts with DNA and proteins. Previous studies conducted by our laboratory showed that the reaction of N-oxidized PhIP metabolites with human albumin in vitro primarily occurs at the Cys(34) residue, to produce an acid-labile linked sulfinamide adduct...
January 18, 2017: Chemical Research in Toxicology
Maomao Zeng, Mengru Zhang, Zhiyong He, Fang Qin, Guanjun Tao, Shuang Zhang, Yahui Gao, Jie Chen
The inhibitory profiles of chilli pepper and capsaicin, as well as their relationship to the formation of heterocyclic amines (HAs) in roast beef patties were investigated using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with principal component analysis (PCA). HAs including 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-1,6-dimethylimidazo[4,5-b]pyridine (DMIP), 2-amino-1,5,6-trimethylimidazo[4,5-b]pyridine (1,5,6-TMIP), 2-amino-3-methyl-3H-imidazo[4,5-f]quinoxaline (IQx), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 1-methyl-9H-pyrido[3,4-b]indole (harman) and 9H-pyrido[3,4-b]indole (norharman) were detected and quantified in beef patties...
April 15, 2017: Food Chemistry
Shouji Zhu, Shichao Xu, Wang Jing, Zhendong Zhao, Jianxin Jiang
p-Menth-3-en-1-amine, 4, and its Schiff base derivatives, 5a-l, were designed and synthesized. They were characterized by FT-IR, ESI(+)-MS, HRMS, (1)H NMR, and (13)C NMR spectral analyses, and their pre-emergence herbicidal activities against ryegrass were evaluated. All of the compounds showed excellent herbicidal activity. The Schiff bases showed stronger herbicidal activities than the original amine 4. These compounds showed herbicidal activities comparable to that of glyphosate. The herbicidal activities of 5k and 5l against ryegrass shoot growth were 78...
December 28, 2016: Journal of Agricultural and Food Chemistry
Medjda Bellamri, Ludovic Le Hegarat, Robert J Turesky, Sophie Langouët
2-Amino-9H-pyrido[2,3-b]indole (AαC) is the most abundant carcinogenic heterocyclic aromatic amine (HAA) formed in mainstream tobacco smoke. AαC is a liver carcinogen in rodents, but its carcinogenic potential in humans is not known. To obtain a better understanding of the genotoxicity of AαC in humans, we have investigated its metabolism and its ability to form DNA adducts in human hepatocytes. Primary human hepatocytes were treated with AαC at doses ranging from 0.1-50 μM, and the metabolites were characterized by ultra-performance LC/ion trap multistage mass spectrometry (UPLC/MS(n))...
December 15, 2016: Chemical Research in Toxicology
Ulrike Holzgrabe, Michael Decker
Bitopic M ligands, that is, ligands that interact both with the ortho- and allosteric binding sites of the M receptor subtypes, hold great potential as novel selective for muscarinic acetylcholine (M) ligands for several therapeutic applications. Areas covered: The patent application describes a set of compounds based on the neurotransmitter acetylcholine applying the Schulman-model for M ligands comprising heterocyclic (often quaternary) amines and a benzene ring (often as benzoic acid esters) to act as bitopic ligands...
December 26, 2016: Expert Opinion on Therapeutic Patents
Genin Gary Huang, Chung-Jay Lee, Jyisy Yang, Che-Hao Chang, Malaichamy Sathiyendiran, Zong-Zhan Lu, Kuang-Lieh Lu
An evanescent wave infrared chemical sensor was developed to selectively detect volatile amines with heterocyclic or phenyl ring. To achieve this goal, a rhenium-based metallacycle with a "molecular-trap" structure was designed and synthesized as host molecules to selectively trap amines with heterocyclic or phenyl ring through Re-amine and π-π interactions. To explore the trapping properties of the material, a synthesized Re-based molecular trap was treated on an IR sensing element, and wide varieties of volatile organic compounds (VOCs) were examined to establish the selectivity for detection of amines...
December 28, 2016: ACS Applied Materials & Interfaces
Zhenfeng Zhang, Nicholas A Butt, Wanbin Zhang
Chiral cyclic structures are found in numerous natural products, pharmaceutical compounds, and important synthetic intermediates. Asymmetric hydrogenation, allowing for the preparation of these complex targets in an environmentally benign and efficient manner, has received much attention over the past few years. This review summarizes the advances in the construction of chiral heterocycles and carbocycles (including cyclic amines, ethers, alcohols, and alkanes) via the asymmetric hydrogenation of nonaromatic cyclic substrates (including prochiral cyclic imines, ketones, and alkenes) using appropriate transition-metal complexes...
December 14, 2016: Chemical Reviews
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