Tri-n-butyltin Hydride-Mediated Radical Reactions of ortho- and meta-Iodobenzamides to Synthesize Benzomacrolactams. Surprising Formation of Biphenyl Compounds from meta-Regioisomers

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Reactions of methyl 4-O-allyl-2,3-di-O-benzyl-6-deoxy-6-(3-iodobenzoylamino)-alpha-D-galactopyranoside, its gluco epimer, methyl 2,3-di-O-benzyl-6-deoxy-6-(3-iodobenzoylamino)4-O-(1-pentenyl)-alpha-D-glucopyranoside and its ortho-regioisomer with tri-n-butyltin hydride were performed in different conditions. Depending on reaction conditions the three meta-iodo isomers gave a surprising amount of biphenyl compounds. The 2-iodo isomer led only to the undesired but expected hydrogenolysis product. No cyclized products were isolated in all the reactions. The structures of the new biphenyl products were elucidated by (1)H and (13)C NMR spectroscopy, DEPT, COSY, HMQC and HMBC experiments and ESI-MS/MS. Mechanisms for the formation of these new biphenyl derivatives and hypotheses to explain the different outcomes for radical reactions of 3- or 2-iodobenzamides were presented.20815041514Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Intrinsic acidity and electrophilicity of gaseous propargyl/allenyl carbocations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The ion/molecule chemistry of four representative propagyl/allenyl cations 1-4 of the general formula R(1)CH(+)-C C-R (a) <-> R(1)CH=C=C(+)-R (b), that is, the reactive C(3)H(3)(+) ions of m/z 39 from EI of propargyl chloride (H(2)C(+)-C C-H, 1a), isomeric C(4)H(5)(+) ions of m/z 53 from EI of 3-butyne-2-ol (2a, H(2)C(+)-C C-CH(3)) and 2-butyne-1-ol (CH(3)-CH(+)-C C-H, 3a), and Ph-C(3)H(2)(+) ions of m/z 115 from 3-phenyl-2-propyn-1-ol (H(2)C(+)-C C-Ph, 4a) was studied via pentaquadrupole mass spectrometry. With pyridine, proton transfer was observed as the predominant process for 1 and the sole reaction channel for the isomeric 2 and 3, whereas 4 reacted preferentially by adduct formation. These outcomes were rationalized using DFT calculations from isodesmic proton transfer reactions. Similar reaction tendencies were observed with acetonitrile and acrylonitrile, with adduct formation appearing again as a minor pathway for 1, 2 and 3, and as a major reaction channel for 4. With 1,3-dioxolane, hydride abstraction was a dominant reaction, with proton transfer and adduct formation competing as side reactions. With 2,2-dimethyl-1,3-dioxolane, an interplay of reactions including methyl anion abstraction, proton transfer, hydride abstraction and adduct formation were observed depending on the ion structure, with 4 reacting again mainly by adduct formation. Proton transfer was also observed as a dominant process in reactions with ethanol for 1, 2 and 3, with 4 being nearly unreactive whereas no adduct formation was observed for any of the carbocations studied. Limited reactivity was exhibited by these ions in cycloaddition reaction with isoprene.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.81125802585Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)RSCCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Cyclopentadienyl and pentamethylcyclopentadienyl ruthenium complexes as catalysts for the total deoxygenation of 1,2-hexanediol and glycerol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The ruthenium aqua complexes [cp*Ru(OH2)(N-N)](OTf) (cp* = eta(5)-pentamethyl-cyclopentadienyl, N-N = 2,2'-bipyridine, phen = 1,10-phenanthroline, OTf(-) = trifluoromethanesulfonate) and the acetonitrile complex [cpRu(CH(3)CN)(bipy)](OTf) (cp = eta(5)-cyclopentadienyl) are water-, acid-, and thermally stable (> 200 degrees C) catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOTf as a co-catalyst, they effect the deoxygenation of 1,2-hexanediol to 1-hexanol and hexane. Glycerol is deoxygenated to 1-propanol in up to 18% yield and under more forcing conditions completely deoxygenated to propene. The structure of the acetonitrile pro-catalyst [ cpRu( CH3CN)( bipy)]( OTf) has been determined by X-ray crystallography (space group P (1) over bar (a = 9.3778(10) angstrom; b = 10.7852(10) angstrom; c = 11.1818(13) angstrom; alpha = 101.718(5)degrees; beta = 114.717(4)degrees; g = 102.712(5)degrees; R = 3.95%).o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.132357366Natural Science and Engineering Research Council of Canada (NSERC)Canadian Foundation for Innovation (CFI)Natural Resources Canada (NRCAN)Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA)BioCap Canada FoundationDuPontOntario Graduate ScholarshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FINEPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Synthesis of potentially bioactive PABA-related N-(aminoalkyl)lactamic amino acids and esters via selective SNAr reactions

Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by SNAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition-elimination SNAr mechanism was confirmed by NMR and MS measurements.40119720

Single-shot biodiesel analysis: Nearly instantaneous typification and quality control solely by ambient mass spectrometry

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Using a simple and easily implemented desorption/ ionization mass spectrometry technique, a tiny droplet of biodiesel placed on the surface of a sheet of paper is analyzed directly and nearly instantaneously under ambient conditions. No pre-separation or sample preparation is required, and clean mass spectra are obtained with great simplicity. In the positive ion mode, easy ambient sonic-spray ionization mass spectrometry, EASI(+)-MS, provides typical profiles of the major components of biodiesel samples, that is, either methyl esters (FAME) or ethyl esters (FREE) of the natural fatty acids and triglycerides (TAG) from residual oil or oil from adulteration. Each FAME (FAEE) or TAG molecule is detected as a single sodiated molecule, [M + Na](+) with relative intensities that correlate well with the known fatty acid profiles of the oil. Using EASI(-)-MS, typical and complementary profiles of free fatty acids (FFA) are obtained, which are detected in their deprotonated forms [FAA - H] -. A general, single-shot approach for biodiesel analysis is therefore described, and samples from different feed-stocks, from blends with petrodiesel, or from either methanol or ethanol traps-esterification are readily typified and major parameters of quality accessed.802078827886FINEPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Charge-tagged N-heterocyclic carbenes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The interception, formation and characterization of the first stable, long lived charge-tagged N-heterocyclic carbenes of the general type 4(x+) (x = 1-3) and analogues is reported. Via ESI(+)-MS of solutions of bromine salts of doubly, triply and quadruply charged imidazolium ion IL (3. Br-n, n = 2-4), the isolated 4(x+) as well as charged aggregates [3.Br(n-x)](x+) likely to be participating in the [3.Br(n-x)](x+) reversible arrow 4(x+) + HBr solution equilibrium could be transferred and characterized in the gas phase. Mimicking the solution equilibrium, the gaseous [3.Br(n-x)](x+) were found to dissociate nearly exclusively via HBr loss during thermal activation via collisions to form gaseous 4(x+), which were found to add to acrolein and acetone.117378Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)INCT-MCTFAPERGSConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Metabolic fingerprinting of royal jelly: characterization and proof of authenticity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Introduction Metabolic fingerprint is a high-throughput screening to provide a sample classification. Objectives Herein, we describe a metabolic fingerpint strategy for proof of authenticity and possible adulteration of natural products. This strategy provides useful and complementary information to food science for content analysis. Methods Twelve samples of commercial royal jelly were analysed by electrospray ionization mass spectrometry (ESI-MS) in the negative mode. ESI-MS/MS was performed for characteristic negatively charged ions. Results Thermostability studies were also performed to royal jelly samples in order to evaluate the change on chemical composition with different times of exposure to heating and storage at room temperature. Conclusion The methodology developed in this work is useful to proof of authenticity and degradation of royal jelly samples using minimum sample preparation and direct injection of extracts.34185190Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

A Highly Effective Antioxidant and Artificial Marker for Biodiesel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Biodiesel is composed of saturated and unsaturated methyl esters of fatty acids formed via transesterification of vegetable oil or animal fat. This chemical nature makes biodiesd much more susceptible to oxidation or autoxidation during long-term storage than conventional petrodiesel. Increasing resistance to oxidation therefore requires the use of antioxidants. This paper investigates the effectiveness of the N,N'-di-sec-butyl-p-phenylenediamine (I) as a antioxidant to improve the oxidative stability of soybean, sunflower and canola biodiesel. Results indicate that the induction period for oxidation of soybean and canola biodiesel is significantly improved with the addition of only 0.2 ppm of the 1, reaching the oxidative stability specification (6 h by the Rancimat test). For sunflower biodiesel, 2.0 ppm of the I was necessary. This additive is also shown to be efficiently detected by the easy ambient sonic-spray ionization mass spectrometry technique, indicating that I and its analogues and derivatives could also be used as versatile artificial markers of biodiesel.2465226526Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Studies and Projects Financing Agency (FINEP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Fingerprinting of propolis by easy ambient sonic-spray ionization mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Chemical profiles of a representative set of 49 propolis ethanolic extracts collected worldwide (North and South America, Europe, Asia and Oceania) were obtained via easy ambient sonic-spray ionization mass spectrometry (EASI-MS). This simple and easily implemented fingerprinting technique analyses directly (without any pre-separation or sample manipulation) a tiny droplet of the ethanolic extract placed on a inert surface under ambient conditions. Data acquisition took about a minute per sample with no substantial sample carry-over. Extraction of propolis with ethanol by using an ultrasonic bath method gave EASI-MS data similar to the traditional maceration method, reducing total analysis time for the crude propolis resin from a week to just ca 1h. Principal component analysis of the EASI-MS data is shown to group samples according to the plant sources of their resins, which characterizes their geographical origin. (C) 2009 Elsevier B.V. All rights reserved.8141671100108Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES