- Emerging use of isotope ratio mass spectrometry as a tool for discrimination of 3,4-methylenedioxymethamphetamine by synthetic route
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Drug profiling, or the ability to link batches of illicit drugs to a common source or synthetic route, has long been a goal of law enforcement agencies. Research in the past decade has explored drug profiling with isotope ratio mass spectrometry (IRMS). This type of research can be limited by the use of substances seized by police, of which the provenance is unknown. Fortunately, however, some studies in recent years have been carried out on drugs synthesized in-house and therefore of known history. In this study, 18 MDMA samples were synthesized in-house from aliquots of the same precursor by three common reductive animation routes and analyzed for 13C, 15N, and 2H isotope abundance using IRMS. For these three preparative methods, results indicate that 2H isotope abundance data is necessary for discrimination by synthetic route. Furthermore, hierarchical cluster analysis using 2H data on its own or combined with 13C and/or 15N provides a statistical means for accurate discrimination by synthetic route.
- Buchanan, Hilary A. S.,Daeid, Niamh Nic,Meier-Augenstein, Wolfram,Kemp, Helen F.,Kerr, William J.,Middleditch, Michael
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Read Online
- Environment-friendly, mild and one-step synthesis of Safrole
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One-step synthesis of safrole, an important flavor compound, was described. Safrole was prepared by Friedel-Crafts reaction of 1,2-methylenedioxybenzene and allyl alcohol with recyclable Catalysts-Nafion-H. Safrole was obtained with a yield of 80 % and little isosafrole was obtained. The catalyst and excess raw material can be recycled and reused.
- Ou, Wenhua,Huang, Hong
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Read Online
- Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins
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An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.
- Yang, Biao,Dong, Kui,Li, Xiang-Sheng,Wu, Li-Zhu,Liu, Qiang
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supporting information
p. 2040 - 2044
(2022/03/17)
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- Molecular modeling and chemical synthesis of new safrol oxime ether derivatives
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Leishmaniasis, a neglected tropical disease with a high worldwide incidence, is considered a public health issue in Minas Gerais and Brazil, with a high degree of morbidity, not to mention the lack of therapeutic arsenal. The cysteine protease (rCPB2.8) and cyclin dependent kinase (CRK3), important enzymes for the parasite’s feasibility, were the targets chosen for investigation of the new drugs. The following study aimed to analyze several oximic derivatives starting from safrol, which can present an affinity profile for selected molecular targets using tools from molecular modeling and bioinformatics, planning and synthesis of brand new substances being tested for leishmanicidal drugs. The study allowed to verify that three oximic derivatives (5a, 5f and 5h) presented high affinity for the CRK3 enzyme, and that the compounds 5c and 5g presented good interaction by the amino acids of the catalytic site of the rCPB2.8 enzyme with atomic distances capable of generating covalent bonds, which are essential for enzyme inhibitory activity.
- Alves, Levy B.,Chagas, Thaynan A. B.,Cordeiro, Mirian M.,Monti, Paloma A. G.,Silva, Mariana G. R.,Souza, Ruth V.,Veloso, Marcia P.
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p. 1476 - 1490
(2021/06/14)
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- AN EFFICIENT PROCESS FOR PREPARATION OF ACYL DERIVATIVES OF ALKYLENEDIOXYBENZENES
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The present disclosure provides a process of preparation of compounds of Formula I comprising the step of : reacting an alkylenedioxybenzene compound of Formula II with an acyl halide of Formula III in presence of a solvent, wherein the step of reacting the alkylenedioxybenzene compound of Formula II with the acyl halide of Formula III is effected in presence of an amphoteric oxide and a Lewis acid so as to immediately quench the compound of formula H-X, formed during the course of the reaction, to substantially eliminate degradation of the compound of any of Formula I and II. The present disclosure also provides for process(es) for preparation of compound of Formula IVa, IVb and IVc.
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- Synthesis of new cyclic imides derived from safrole, structure-and ligand-based approaches to evaluate potential new multitarget agents against species of leishmania
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Background: Leishmaniasis is a neglected disease that does not have adequate treatment. It affects around 12 million people around the world and is classified as a neglected disease by the World Health Organization. In this context, strategies to obtain new, more active and less toxic drugs should be stimulated. Sources of natural products combined with synthetic and chemoinformatic methodologies are strategies used to obtain molecules that are most likely to be effective against a specific disease. Computer-Aided Drug Design has become an indispensable tool in the pharmaceutical industry and academia in recent years and has been employed during various stages of the drug design process. Objectives: Perform structure-and ligand-based approaches, synthesize and characterize some compounds with materials available in our laboratories to verify the method’s efficiency. Methods: We created a database with 33 cyclic imides and evaluated their potential anti-Leishmanial activity (L. amazonensis and L. donovani) through ligand-and structure-based virtual screening. A diverse set selected from ChEMBL databanks of 818 structures (L. donovani) and 722 structures (L. amazonensis), with tested anti-Leishmanial activity against promastigotes forms, were classified according to pIC50 values to generate and validate a Random Forest model that shows higher statistical indices values. The structures of four different L. donovani enzymes were downloaded from the Protein Data Bank and the imides’ structures were submitted to molecular docking. So, with available materials and technical feasibility of our laboratories, we have synthesized and characterized seven compounds through cyclization reactions between isosafrole and maleic anhydride followed by treatment with different amines to obtain new cyclic imides to evaluate their anti-Leishmanial activity. Results: In silico study allowed us to suggest that the cyclic imides 516, 25, 31, 24, 32, 2, 3, 22 can be tested as potential multitarget molecules for leishmanial treatment, presenting activity probability against four strategic enzymes (Topoisomerase I, N-myristoyltransferase, cyclophilin and O-acetylserine sulfhydrylase). The compounds synthesized and tested presented pIC50 values less than 4.7 for Leishmania amazonensis. Conclusion: After combined approach evaluation, we have synthesized and characterized seven cyclic imides by IR,1 H NMR,13 C-APT NMR, COSY, HETCOR and HMBC. The compounds tested against promastigote forms of L. amazonensis presented pIC50 values less than 4.7, showing that our method was efficient in predicting true negative molecules.
- Athayde-Filho, Petr?nio F.,Costa, Normando A. da Silva,Lima, Tatjana K. de Souza,Lira, Bruno F.,Luis, Cristiane C. S.,Luis, José A. de Sousa,Rocha, Juliana da Camara,Scotti, Luciana,Scotti, Marcus T.
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- Synthesis, in silico study, theoretical stereochemistry elucidation and antifungal activity of new imides derived from safrole
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Ten imides derived from safrole, 4a-4j, were synthesized and their structures were fully characterized by infrared (IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRMS) analysis. Among the ten imides studied, eight are new. The compounds were evaluated in an in silico study and showed strong to moderate antifungal activity against various strains of Candida and Cryptococcus. In particular, compounds 4b, 4c and 4h exhibited strong antifungal activity, with minimum inhibitory concentration (MICs) between 0.17-0.73 μmol mL-1. The compound 4j exhibited antifungal activity with MIC 1.28 μmol mL-1 for all strains tested. In silico studies of the parameters of Lipinski's rule of five indicated that these compounds are potential new drug candidates. The predict oral bioavailability can be evaluated through these parameters. In addition, a computational study helped assigning the stereochemistry of compound 4j, where the synthesized mixture is composed by two stereoisomers, 4j(1) (SRR) and 4j(2) (RSS).
- Barbosa-Filho, José M.,Cordeiro, Laísa V.,Costa, Normando A. S.,Cruz, Luiz E. G.,Lima, Edeltrudes O.,Lira, Bruno F.,Rocha, Gerd B.,Souza, Helivaldo D. S.,Vilela, Raquel F.,de Assis, Kelyonara M. S.,de Athayde-Filho, Petronio F.
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p. 2091 - 2103
(2020/10/12)
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- Preferential Photoreaction in a Porous Crystal, Metal-Macrocycle Framework: PdII-Mediated Olefin Migration over [2+2] Cycloaddition
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A nanosized confined space with well-defined functional surfaces has great potential to control the efficiency and selectivity of catalytic reactions. Herein we report that a 1,6-diene, which normally forms an intramolecular [2+2] cycloadduct under photoirradiation, preferentially undergoes a photoinduced olefin migration in a porous crystal, metal-macrocycle framework (MMF), and alternatively [2+2] cycloaddition is completely inhibited in the confined space. A plausible reaction mechanism for olefin migration triggered by the photoinduced dissociation of the Pd-Cl bond is suggested based on UV-vis diffuse reflectance spectroscopy, single-crystal XRD, and MS-CASPT2 calculation. The substrate scope of the photoinduced olefin migration in MMF was also examined using substituted allylbenzene derivatives.
- Yonezawa, Hirotaka,Tashiro, Shohei,Shiraogawa, Takafumi,Ehara, Masahiro,Shimada, Rintaro,Ozawa, Takeaki,Shionoya, Mitsuhiko
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supporting information
p. 16610 - 16614
(2018/12/11)
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- A PROCESS FOR PREPARATION OF ALKENYL AND ALKYL DERIVATIVES OF ALKYLENEDIOXYBENZENE
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The present disclosure generally relates to the method of preparation of compounds of Formula IV. An aspect of the present disclosure relates to a process for preparation of compound of Formula IV, said process comprising the step of reacting an alkylenedioxybenzene compound of Formula II with an acyl halide of Formula III in presence of a solvent, characterized in that the step of reacting the alkylenedioxybenzene compound of Formula II with the acyl halide of Formula III is effected in the presence of an amphoteric oxide so as to in-situ quench the compound of formula H-X formed during the course of the reaction, thereby substantially eliminating degradation of the compounds of Formula IV and Formula II.
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- Cobalt-Catalyzed Allylic C(sp3)-H Carboxylation with CO2
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Catalytic carboxylation of the allylic C(sp3)-H bond of terminal alkenes with CO2 was developed with the aid of a Co/Xantphos complex. A wide range of allylarenes and 1,4-dienes were successfully transformed into the linear styrylacetic acid and hexa-3,5-dienoic acid derivatives in moderate to high yields, with excellent regioselectivity. The carboxylation showed remarkable functional group tolerability, so that selective addition to CO2 occurred in the presence of other carbonyl groups such as amide, ester, and ketone. Since styrylacetic acid derivatives can be readily converted into optically active γ-butyrolactones through Sharpless asymmetric dihydroxylation, this allylic C(sp3)-H carboxylation showcases a facile synthesis of γ-butyrolactones from simple allylarenes via short steps.
- Michigami, Kenichi,Mita, Tsuyoshi,Sato, Yoshihiro
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supporting information
p. 6094 - 6097
(2017/05/08)
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- Toward a mild dehydroformylation using base-metal catalysis
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Dehydroformylation, or the reaction of aldehydes to produce alkenes, hydrogen gas, and carbon monoxide, is a powerful transformation that is underdeveloped despite the high industrial importance of the reverse reaction, hydroformylation. Interestingly, nature routinely performs a related transformation, oxidative dehydroformylation, in the biosynthesis of cholesterol and related sterols under mild conditions using base-metal catalysts. In contrast, chemists have recently developed a non-oxidative dehydroformylation method; however, it requires high temperatures and a precious-metal catalyst. Careful study of both approaches has informed our efforts to design a base-metal catalyzed, mild dehydroformylation method that incorporates benefits from each while avoiding several of their respective disadvantages. Importantly, we show that cooperative base metal catalysis presents a powerful, mechanistically unique approach to reactions which are difficult to achieve using conventional catalyst design.
- Abrams, Dylan J.,West, Julian G.,Sorensen, Erik J.
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p. 1954 - 1959
(2017/03/09)
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- Alkene isomerisation catalysed by a ruthenium PNN pincer complex
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The [Ru(CO)H(PNN)] pincer complex based on a dearomatised PNN ligand (PNN: 2-di-tert-butylphosphinomethyl-6-diethylaminomethylpyridine) was examined for its ability to isomerise alkenes. The isomerisation reaction proceeded under mild conditions after activation of the complex with alcohols. Variable-temperature (VT) NMR experiments to investigate the role of the alcohol in the mechanism lend credence to the hypothesis that the first step involves the formation of a rearomatised alkoxide complex. In this complex, the hemilabile diethylamino side-arm can dissociate, allowing alkene binding cis to the hydride, enabling insertion of the alkene into the metal-hydride bond, whereas in the parent complex only trans binding is possible. During this study, a new uncommon Ru0 coordination complex was also characterised. The scope of the alkene isomerisation reaction was examined. The catalyst tested positive! A dearomatised ruthenium PNN (2-di-tert-butylphosphinomethyl-6-diethylaminomethylpyridine) pincer complex, [Ru(CO)H(PNN)], was evaluated as an alkene isomerisation catalyst. The isomerisation reaction was greatly accelerated by the addition of alcohols, in particular isopropanol. Isomerisation of terminal to internal alkenes took place at room temperature. A mechanism was proposed based on variable-temperature NMR spectroscopy.
- Perdriau, Sébastien,Chang, Mu-Chieh,Otten, Edwin,Heeres, Hero J.,De Vries, Johannes G.
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supporting information
p. 15434 - 15442
(2016/02/18)
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- Biphasic hydroformylation of substituted allylbenzenes with water-soluble rhodium or ruthenium complexes
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The water-soluble complexes [Rh(CO)(Pz)(L)]2 and [HRu(CO)(CH3CN)(L)3][BF4] [L = TPPMS (m-sulfonatophenyl-diphenylphosphine) and TPPTS (tris-m-sulfonato- phenylphosphine)] were used for the first time as catalyst precursors for the hydroformylation of eugenol, estragole, safrole and trans-anethole under moderate conditions in biphasic media. Under mild reaction conditions the substrates showed the following reactivity order: eugenol > estragole ≈ safrole > trans-anethole. The use of cetyl-trimethylammonium chloride (CTAC) as phase transfer agent inhibits the isomerization reaction, reaching high selectivity for the hydroformylation products (80-94%). The catalytic phase can be recycled up to four times with a decrease in the activity over time but maintaining its high selectivity.
- Melean, Luis G.,Rodriguez, Mariandry,Romero, Marynell,Alvarado, Maria L.,Rosales, Merlin,Baricelli, Pablo J.
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experimental part
p. 117 - 123
(2012/01/03)
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- Regioselective platinum catalyzed β-hydrosilylation of allylic benzene derivatives with cyclic siloxane d4H
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Conditions have been found for an efficient regioselective β-hydrosilylation of allylbenzene, 2-allyl-1-trimethylsiloxybenzene, 4-allyl-1,2-(methylenedioxy)benzene, allylpentafluorobenzene, and 4-allyl-2-methoxy-1-trimethylsiloxybenzene with D4H in the presence of Karstedt's-catalyst or platinum black under mild conditions leading quantitatively to functionalized tetramethylcyclosiloxanes 3.
- El Malki, Abdelghani,Hannioui, Abdellah,El Mostapha, Rakib,Knouzi, Nourredine,Vaultier, Michel
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experimental part
p. 361 - 363
(2012/05/31)
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- Rhodium-catalyzed one-pot hydroformylation-cyclization of allylbenzene derivatives: Simple and efficient route to 5,6-dihydronaphthalenes
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The one-pot hydroformylation-cyclization of allylbenzene derivatives by the catalyst system Rh(CO)2acac/ultranox626/CO/H2/CH2Cl2 led chemoselectively to 5,6-dihydronaphthalene derivatives 5a-d in good yields. The addition of a catalytic amount of H3PO4 enhanced in situ the cyclization process via the nucleophilic attack on the carbonyl group of the linear aldehyde, and finally the elimination of alcohol. The type of substitution on phenyl group of the allylbenzene is of great importance in enhancing the cyclization process.
- Alhaffar, Mouheddin,Suleiman, Rami,Ali, Bassam El
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experimental part
p. 778 - 782
(2010/07/06)
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- Studies towards the identification of putative bioactive conformation of potent vasodilator arylidene N-acylhydrazone derivatives
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In this report we disclose the synthesis, vasodilatory activity, and identification of bioactive conformation of new N-acylhydrazone and N-methyl-N-acylhydrazone derivatives, structurally designed by bioisosteric replacements of previously described cardioactive compounds LASSBio-294 and its N-methyl derivative LASSBio-785. Some of these novel derivatives presented improved vasorelaxant properties, being new cardiovascular drug candidates.
- Kuemmerle, Arthur E.,Raimundo, Juliana M.,Leal, Carla M.,da Silva, Givanildo S.,Balliano, Tatiane L.,Pereira, Mariano A.,de Simone, Carlos A.,Sudo, Roberto T.,Zapata-Sudo, Gisele,Fraga, Carlos A.M.,Barreiro, Eliezer J.
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experimental part
p. 4004 - 4009
(2009/12/04)
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- Potassium Fluoride on Alumina - a Versatile Reagent for Isomerisation of Olefins
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Olefins undergo smooth isomerization to the thermodynamically more stable form on treatment with potassium fluoride coated on alumina.
- Radhakrishna, A.S.,Suri, S.K.,Rao, K.R.K.Prasad,Sivaprakash, K.,Singh, B.B.
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p. 345 - 348
(2007/10/02)
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- Catalytic Double Bond Isomerization by Polystyrene-Anchored RuCl2(PPh3)3
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Dichlorotris(triphenylphosphine)ruthenium has been anchored to diphenylphosphinated styrene-divinylbenzene copolymer.The resulting leaching-resistant catalyst was employed successfully for the isomerization of allylbenzenes and allyl alcohols in numerous turnovers.The stability of the catalyst was examined in different media, and its performances were compared with those of homogeneous RuCl2(PPh3)3 and with those of polymer-bound as well as of free RhCl(PPh3)3 and IrCl(CO)(PPh3)2
- Zoran, Amikam,Sasson, Yoel,Blum, Jochanan
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p. 255 - 260
(2007/10/02)
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- Process for the isomerization of aromatic alkenyl compounds
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Aromatic alkenyl compounds, for example, eugenol and safrole, are isomerized, for example to isoeugenol and isosafrole, by contact with a ruthenium or osmium catalyst.
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