- Synthesis of palladium complexes with anionic N,NR- or neutral NH,NR-theophylline-derived NHC ligands
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Four C8-halogenated theophyllines (1–4) featuring N7-methyl or N7-allyl and C8-chloro or C8-bromo substituents have been prepared. The halogenotheophyllines react with [Pd(PPh3)4] in an oxidative addition to give complexes of type trans-[Pd(theophyllinato)X(PPh3)2] (trans-[5]–trans-[8]). The protonation of the unsubstituted theophyllinato ring-nitrogen atom to give the pNHC complexes was achieved either by performing the oxidative addition of 1 in the presence of NH4BF4 to give complex trans-[9]BF4 or by N-protonation of the coordinated theophyllinato ligand in trans-[6]–trans-[8] with HBF4·Et2O to give complexes trans-[10]BF4–trans-[12]BF4. The molecular structures of trans-[5], trans-[7], trans-[9]BF4, trans-[11]BF4 and trans-[12]BF4 were determined by X-ray diffraction showing significant differences of comparable metric parameters in the theophylline-derived five-membered diaminoheterocycles. No interaction of the N-allyl substituents with the metal center was observed.
- Hahn, F. Ekkehardt,Hervé, Alexandre,Jahnke, Mareike C.,Kampert, Florian
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- Shedding light on the bimolecular interactions of Cafaminol and human serum albumin: spectroscopic characterization and in-silico investigation
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Cafaminol, also known as methylcoffanolamine, is a vasoconstrictor and anticatarrhal of the methylxanthine family, which is used as a nasal decongestant. This study aimed to investigate the interaction mechanisms of human serum albumin (HSA) with Cafaminol, through several spectroscopic (fluorescence quenching, UV-visible absorption, and circular dichroism (CD) spectroscopies) and molecular modeling techniques. Stern-Volmer plots were employed to specify the fluorescence quenching mechanism, while the simulation methods were utilized to deduce the approximate binding position of Cafaminol on HSA. On the other hand, thermodynamic parameters, enthalpy and entropy changes, were determined to be, respectively, ?105.88 (kJ mol?1) and ?282.34 (J mol?1 K?1), using the Van't Hoff equation and analyzed later to specify the main acting forces between Cafaminol and HSA. Overall results revealed the binding of Cafaminol to the site I of HSA, as a result of an enthalpy-driven process, mainly through the van der Waals and hydrogen bonding interactions. Static quenching mechanism was found to be responsible for the fluorescence quenching of HSA in the Cafaminol presence, while the number of binding sites and apparent binding constant were measured accordingly. Docking results proposed that Cafaminol and HSA interact with a binding free energy (ΔG) of ?6.5 kcal mol?1 Communicated by Ramaswamy H. Sarma.
- Alavianmehr, Mohamad Mehdi,Behrouz, Somayeh,Mohammad-Aghaie, Delara,Parvizi, Negar,Soltani Rad, Mohammad Navid
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- Synthetic Transformations of Sesquiterpene Lactones. 11.* Conjugates Based on Caffeine and Eudesmanolides with N-Containing Linkers
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8-(Aminoalkylamino)caffeine or 8-(piperazinyl)caffeine were formed in high yields by reacting 8-bromo- or 8-chlorocaffeine with linear and cyclic diamines using microwave-assisted organic synthesis. These amines were highly reactive in Michael reactions with sesquiterpene lactones containing active methylene groups. Conjugates with caffeine and eudesmanolide moieties bonded by a N-containing linker were synthesized.
- Reshetnikov,Patrushev,Shults
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Read Online
- Radical Carbonyl Umpolung Arylation via Dual Nickel Catalysis
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The formation of carbon-carbon bonds lies at the heart of synthetic organic chemistry and is widely applied to construct complex drugs, polymers, and materials. Despite its importance, catalytic carbonyl arylation remains comparatively underdeveloped, due
- Huang, Huan-Ming,Bellotti, Peter,Erchinger, Johannes E.,Paulisch, Tiffany O.,Glorius, Frank
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supporting information
p. 1899 - 1909
(2022/02/01)
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- 8-Ethynylxanthines as promising antiproliferative agents, angiogenesis inhibitors, and calcium channel activity modulators
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[Figure not available: see fulltext.] Synthetic procedures for the preparation of 8-ethynylxanthines by treating 8-bromocaffeine and 8-bromopentoxifylline with terminal acetylenes were elaborated. Certain ethynylxanthine derivatives exhibit high in vitro antiproliferative activity against a panel of cancer cell lines, matrix metalloproteinase and in vitro angiogenesis inhibitory activity. Ca2+ channel blocking and agonist activity of the synthesized ethynylxanthines was discussed based on data obtained on the H9C2, SH-SY5Y, and A7R5 cell lines.
- Arsenyan, Pavel,Vasiljeva, Jelena,Domracheva, Ilona,Kanepe-Lapsa, Iveta
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p. 776 - 785
(2020/07/27)
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- Organic semiconductor compounds comprising caffeine and Organic solar cell comprising the same
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The present invention relates to an organic semiconductor compound comprising caffeine and an organic solar cell comprising the same, wherein and the organic semiconductor compound of the present invention can introduce caffeine into an end group, thereby
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Paragraph 0120-0124
(2020/04/22)
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- Site-Selective C–H Functionalization of (Hetero)Arenes via Transient, Non-symmetric Iodanes
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Fosu, Hambira, and colleagues describe the direct C–H functionalization of medicinally relevant arenes or heteroarenes. This strategy is enabled by transient generation of reactive, non-symmetric iodanes from anions and PhI(OAc)2. The site-selective incorporation of Cl, Br, OMs, OTs, and OTf to complex molecules, including within medicines and natural products, can be conducted by the operationally simple procedure included herein. A computational model for predicting site selectivity is also included. The discovery of new medicines is a time- and labor-intensive process that frequently requires over a decade to complete. A major bottleneck is the synthesis of drug candidates, wherein each complex molecule must be prepared individually via a multi-step synthesis, frequently requiring a week of effort per molecule for thousands of candidates. As an alternate strategy, direct, post-synthetic functionalization of a lead candidate could enable this diversification in a single operation. In this article, we describe a new method for direct manipulation of drug-like molecules by incorporation of motifs with either known pharmaceutical value (halides) or that permit subsequent conversion (pseudo-halides) to medicinally relevant analogs. This user-friendly strategy is enabled by combining commercial iodine reagents with salts and acids. We expect this simple method for selective, post-synthetic incorporation of molecular diversity will streamline the discovery of new medicines. A strategy for C–H functionalization of arenes and heteroarenes has been developed to allow site-selective incorporation of various anions, including Cl, Br, OMs, OTs, and OTf. This approach is enabled by in situ generation of reactive, non-symmetric iodanes by combining anions and bench-stable PhI(OAc)2. The utility of this mechanism is demonstrated via para-selective chlorination of medicinally relevant arenes, as well as site-selective C–H chlorination of heteroarenes. Spectroscopic, computational, and competition experiments describe the unique nature, reactivity, and selectivity of these transient, unsymmetrical iodanes.
- Fosu, Stacy C.,Hambira, Chido M.,Chen, Andrew D.,Fuchs, James R.,Nagib, David A.
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supporting information
p. 417 - 428
(2019/02/14)
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- General Entry into o-,o′-Heteroatom-Linked N-(Hetero)aryl-Imidazole Motifs by Gold-Catalysed Formal [3+2]-Dipolar Cycloaddition
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A general redox-neutral approach into the o-,o′-heteroatom-linked N-(hetero)aryl-imidazole family of heteroaromatics has been developed. New types of heteroatom substituted carbimidoyl nitrenoids are efficiently realised from robust, bench-stable N-(heteroaryl)-pyridinium-N-aminides by formal gold-catalysed [3+2]-dipolar cycloadditions across ynamides. Broad structural variety and functional group tolerance allows rapid access into diverse functionalised scaffolds, as exemplified by the preparation of 8 different heteroaromatic cores. (Figure presented.).
- Garzón, Miguel,Arce, Elsa M.,Reddy, Raju Jannapu,Davies, Paul W.
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p. 1837 - 1843
(2017/06/09)
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- ETHYNYLXANTHINES, PREPARATION AND USE AS CALCIUM ION CHANNEL MODULATORS
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The present invention relates to novel pharmaceutical compounds, which exhibit ability to act as calcium ion channel modulators, methods for their synthesis and the treatment and/or prevention of various diseases and disorders including deregulated calcium ion channel activity.
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Page/Page column 11; 12
(2016/10/27)
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- Caffeinated compounds and compositions for treatment of amyloid diseases and synucleinopathies
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Compounds and their pharmaceutically acceptable salts for treatment of β-amyloid diseases, such as observed in Alzheimer's disease and synucleinopathies, such as Parkinson's disease.
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Page/Page column 30; 31
(2015/11/09)
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- Aerobic photooxidative bromination of aromatic compounds using carbon tetrabromide mediated by anthraquinone-2-carboxylic acid
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We developed the aerobic photooxidative bromination of aromatic compounds using carbon tetrabromide in the presence of anthraquinone-2-carboxylic acid under visible light irradiation.
- Tanaka, Masanori,Kamito, Yuji,Lei, Cui,Tada, Norihiro,Itoh, Akichika
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p. 5886 - 5888
(2015/11/02)
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- CAFFEINATED COMPOUNDS AND COMPOSITIONS FOR TREATMENT OF AMYLOID DISEASES AND SYNUCLEINOPATHIES
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Compounds and their pharmaceutically acceptable salts for treatment of Beta-amyloid diseases, such as observed in Alzheimer's disease and synucleinopathies, such as Parkinson's disease
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Page/Page column 39; 40
(2013/05/21)
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- 8-Bromocaffeine (8-BC): A new versatile reagent for conversion of aldoximes into nitriles
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A rapid and highly convenient synthesis of nitriles from the corresponding aldoximes using 8-bromocaffeine (8-BC) is described. In this protocol, aldoximes react with 8-BC in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and N,N-dimethylformamide (DMF) to furnish the corresponding nitriles under both microwave-assisted and/or conventional heating (reflux) conditions in short times and in good to excellent yields. This methodology is highly efficient for structurally diverse aldoximes including aliphatic, aromatic, and heteroaromatic oximes. Georg Thieme Verlag Stuttgart · New York.
- Soltani Rad, Mohammad Navid,Behrouz, Somayeh,Nekoei, Abdo-Reza
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experimental part
p. 1191 - 1198
(2012/06/04)
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- In situ generation and trapping of aryllithium and arylpotassium species by halogen, sulfur, and carbon electrophiles
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(Chemical Equation Presented) A general method has been developed for in situ trapping of arylmetal intermediates by halogen, sulfur, ketone, and aldehyde electrophiles affording the functionalization of the most acidic position in arene. Pentafluorobenzene, benzothiazole, and benzoxazole can be functionalized by using K3PO4 base. For less acidic arenes, tBuOLi base is required. Arenes with DMSO pKa values of 35 or less are reactive. 2009 American Chemical Society.
- Popov, Ilya,Do, Hien-Quang,Daugulis, Olafs
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supporting information; experimental part
p. 8309 - 8313
(2010/01/16)
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- Synthesis of 8-substituted xanthine derivatives by Suzuki cross-coupling reaction
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A Suzuki cross-coupling reaction procedure was developed to prepare 8-substituted 3,7-dihydropurine-2,6-dione (xanthine) derivatives. 8-Halogen-substituted xanthines were reacted with phenyl- and styrylboronic acids. The best results were obtained using tetrakis(triphenylphosphine)palladium(0) and tripotassium phosphate in dimethylformamide. The developed procedure allows for a convergent synthesis of pharmacologically active 8-substituted xanthine derivatives.
- Vollmann, Karl,Mueller, Christa E.
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p. 871 - 879
(2007/10/03)
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- Effect of Trifluoromethyl and Other Substituents on Activity of Xanthines at Adenosine Receptors
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An aryl p-(trifluoromethyl) substituent increases the affinity of 1,3-disubstituted 8-phenylxanthines at A2a-adenosine receptors, while having little effect on affinity at A1-adenosine receptors.In contrast, an aryl p-(trifluoromethy
- Jacobson, Kenneth A.,Shi, Dan,Gallo-Rodriguez, Carola,Manning, Malcolm,Mueller, Christa,et al.
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p. 2639 - 2644
(2007/10/02)
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- SOME NEW HALO- AND CYANO-DEMERCURATION REACTIONS OF 8-ACETOXYMERCURI- AND 8,8'-MERCURIBIS-CAFFEINES
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On acting upon 8-acetoxymercuri-caffeine (1) and/or 8,8'-mercuribis-caffeine (2) with aqueous solutions of KI3, KBr3, ICN, BrCN or with an excess of neat liquid SO2Cl2, SCl2, S2Cl2, and SF4, the following 8-X-substituted caffeines, X=CN (3), I (4), Br (5), Cl (6), and F (7), were prepared, sometimes in excellent yields.Seven of these methods of demercuration of organomercurials have not been reported so far in the literature.
- Skulski, Lech,Wroczynski, Piotr
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p. 975 - 982
(2007/10/02)
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