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Asymmetric Alkenylation of Enones and Other α,β-Unsaturated Carbonyl Derivatives Using Chiral 3,3′-Disubstituted Binaphthols and BoronatesGuobadia, Bobby 22 May 2009 (has links)
Various α,β-unsaturated carbonyl compounds and derivatives were explored in order to expand the range of substrates for the 1,4-addition of alkenylboronates using 3,3′-disubstituted binaphthols. Enones 2.60 were examined and found to be suitable for conjugate addition under our proposed reaction conditions.
The asymmetric 1,4-additions of alkenylboronates to enones 2.60 using catalytic amounts of 3,3′-disubstituted binaphthols was shown to occur with moderate to good yields and high enantioselectivities. The chiral products could serve as enantioenriched substrates for further transformation such as asymmetric reduction, which was performed with good yield and selectivity. The absolute configuration for the alkenylation of enones was also confirmed to be the (R) enantiomer using (S)-3,3′-disubstituted binaphthols via X-ray crystallographic analysis.
Investigations into selective Baeyer-Villiger oxidation of 1,4-addition products of enones was also examined. Although the desire ester products were not obtained, intriguing informative findings were still obtained from the investigation.
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Asymmetric Alkenylation of Enones and Other α,β-Unsaturated Carbonyl Derivatives Using Chiral 3,3′-Disubstituted Binaphthols and BoronatesGuobadia, Bobby 22 May 2009 (has links)
Various α,β-unsaturated carbonyl compounds and derivatives were explored in order to expand the range of substrates for the 1,4-addition of alkenylboronates using 3,3′-disubstituted binaphthols. Enones 2.60 were examined and found to be suitable for conjugate addition under our proposed reaction conditions.
The asymmetric 1,4-additions of alkenylboronates to enones 2.60 using catalytic amounts of 3,3′-disubstituted binaphthols was shown to occur with moderate to good yields and high enantioselectivities. The chiral products could serve as enantioenriched substrates for further transformation such as asymmetric reduction, which was performed with good yield and selectivity. The absolute configuration for the alkenylation of enones was also confirmed to be the (R) enantiomer using (S)-3,3′-disubstituted binaphthols via X-ray crystallographic analysis.
Investigations into selective Baeyer-Villiger oxidation of 1,4-addition products of enones was also examined. Although the desire ester products were not obtained, intriguing informative findings were still obtained from the investigation.
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Characteristics and source apportionment of carbonyl compounds in Kaohsiung Area, Southern TaiwanHuang, Chin-hung 13 June 2012 (has links)
The seasonal and diurnal concentrations of atmospheric carbonyls were measured by the LpDNPH-Cartridge and the microcomputer air sampling device at Nan-Chie and Hsiung-Kong sites in Kaohsiung area. Then, factor analysis and absolute principal component analysis were also used to determine the source apportionment in Kaohsiung area.
Total concentrations of carbonyls were higher in Summer than in winter at Nan-Chie and Hsiung-Kong sites. Measurements showed that the highest carbonyls were formaldehyde and acetaldehyde, due to the fact that photochemical activities are stronger in summer than in winter.
The concentrations of total carbonyls, formaldehyde, acetaldehyde were showed similar diurnal variations, that highest concentrations were found in the morning and noon, then drop down at afternoon and increased at night. Due to the fact that photochemical activities and vehicle exhausts.
C1-C3 ratio indicated the local participation of anthropogenic hydrocarbons was important in the production of carbonyls in the Kaohsiung area. C1/C2 was highest in the summer than in the winter, that photochemical activities cause highest concentrations of formaldehyde, especially in the summer noon.
The results of factor analysis and absolute principal component analysis showed that the primary pollution sources at Nan-Chie were traffic exhausts (diesel and gasoline vehicle) and stationary sources (petrochemical and food industry) and restaurant emissions, and the primary pollution sources at Hsiung-Kong were traffic exhausts (diesel and gasoline vehicle), stationary emissions (metal assembly and petrochemical industry) and restaurant emissions.
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Analysis of Fuel Performance and Exhaust Emissions of Ultra-low Sulphur Diesel Blending with BiofuelsChen, Kung-Fu 17 February 2005 (has links)
This study investigated the fuel properties, engine performances, and emissions of two biodiesels and diesel. The fuels examined were D100 (ultra-low sulfur diesel), B20 (20% palm biodiesel +80% ultra-low sulfur diesel) and B100 (palm biodiesel).
The fuel properties analysis results showed that the benefits of biodiesel were high cetane value, extremely low sulfur and aromatic contents, and good lubricity. While the defects of biodiesel were high pour point. The particulates emitted from the burning of D100, B100, B20 were mainly fine particulates, also known as young aerosols. Particles smaller than 2.5 µm easily enter the trachea and bronchus via the upper respiratory tract, finally deposit on the alveolus, which could cause severe injury to human health.
The emission of soluble organic fraction (SOF) from diesel engine using D100, B100 and B20 were 23.2%, 19.9% and 20.2%, respectively. The SOF of D100 is slightly higher than B100 and B20. It suggested that adding biodiesel into diesel can decrease SOF and thus reduce the potential danger to human health.
The original total PAHs concentration of tail gas emitted from engines using D100, B100 and B20 were 241, 50.6 and 98.8 µg/m3, respectively. Adding 20% biodiesel into D100 could reduce 59.0% of PAHs emission. Moreover, the original total BaPeq concentration of tail gas emitted from diesel engines using D100, B100 and B20 were 0.714, 0.509 and 0.570 µg/m3, respectively. Adding 20% biodiesel into D100 could also reduce 20.2% of total BaPeq emission. Hence, adding biodiesel into diesel can effectively reduce the emission of PAHs and the potential danger to human health.
The emission factors of carbonyl compounds from diesel engines using D100, B100 and B20 were 395, 1,170 and 326 mg/BHP-hr, respectively. carbonyl compounds of B100 were obviously higher than D100 and B20. The results indicated that using pure palm biodiesel in diesel engine can increased the emission of carbonyl compounds. However, adding 20% biodiesel into D100 can effectively reduce 17.5% of carbonyl compounds emission.
Keyword: ultra-low sulfur diesel, palm biodiesel, fuel properties¡BThe emission of soluble organic fraction (SOF)¡BPAHs¡Bcarbonyl compounds¡C
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Mass spectrometry-based identification and characterization of protein and peptide adducts of lipoxidation-derived aldehydes /Chavez, Juan D. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 190-208). Also available on the World Wide Web.
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Determination of atmospheric carbonyls and carboxylic acids by denudersampling, gradient elution and capillary electrophoresisChan, King-yee., 陳景怡. January 2003 (has links)
published_or_final_version / abstract / toc / Chemistry / Master / Master of Philosophy
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New aspects of organometallic chemistry / by Michael Lloyd WilliamsWilliams, Michael Lloyd January 1985 (has links)
Bibliography: leaves 204-208 / 208 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, 1985
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Estudo de compostos carbonílicos e os respectivos ácidos hidroxialquilsulfônicos em vinhosAzevedo, Luciana Cavalcante de January 2007 (has links)
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TESE VERSÃO FINAL_completaseg.pdf: 1586143 bytes, checksum: a57cce30857cde7aaf0e0e909a4950aa (MD5) / A análise dos compostos carbonílicos
(CCs) é um dos procedimentos de
rotina em muitos laboratórios de cont
role de qualidade de bebidas, no entanto,
atualmente são quantificados
apenas os CCs totais expressos em teores de
acetaldeído, sem que sejam associados outros CCs com a sua qualidade.
Esses compostos
possuem impacto olfativo no aroma dos vinhos e uma
forte afinidade pelo bissulfito, adicio
nado na vinificação, podendo formar
adutos estáveis que interferirão também no aroma. Os maiores desafios,
no entanto, consistem em predizer qu
ais CCs têm maior afinidade pelo
S(IV), que circunstâncias favorecem es
ta interação e como analisá-los
em conjunto. Por esse motivo, no presente estudo foi avaliado o perfil de
22 CCs em “solução modelo" e em
dez amostras reais de vinhos,
empregando uma metodologia desenvolvida e validada para analisá-los
de forma simultânea, que utiliza CLAE co
m sistema de gradiente binário
de eluição.
Baseado na Análise de Componentes Principais (ACP) e nas
constantes de dissociação (K
d
), os resultados revelaram que os aldeídos
alifáticos formam adutos com S(IV), enquanto as cetonas, os aldeídos
cíclicos e os trans-alcenais interagiram fracamente e são encontrados
predominantemente em sua forma livre
. Estes resultados revelaram
também que a faixa de pH entre 10 e 11 foi definida como a mais
apropriada para a dissociação do adu
to CC-S(IV), favorecendo a
quantificação segura dos CCs na form
a total. Nos vinhos e uvas
estudados foram identificados o fo
rmaldeído, acetaldeído, butanal,
hexanal, furfural, benzaldeído,
E
-penten-2-al, ciclo hexanona e 2-etil
hexanal, sendo este último identificado
pela primeira vez neste tipo de
matriz. Os quatro primeiros aldeídos citados podem ser considerados
aromas primários por estarem presentes tanto nos vinhos quanto nas
uvas que lhes deram origem. / Carbonyl compounds analysis is one of the routine procedures in
several laboratories of control and
quality of beverages. However, only
total CCs, expressed by the acetald
ehyde concentration, are quantified
which results in a lack of knowl
edge about the beverage’s quality and
other CC concentrations. Although present in minute quantity, other CCs
have a strong olfactory impact in many fermented beverages. In addition,
the CCs found in wines have a strong affinity for bisulfite, added in
winemaking process, and can form st
able adducts, which will also
interfere in the characteristics of ar
oma. The greatest challenge, however,
is to predict which CCs have the st
rongest affinity for S(IV), what
conditions favor this interaction and ho
w to analyze them jointly. In order
to better understand the reaction of CC-
bisulfite adduct formation, this
study has evaluated the role of 22 CCs in a “model soluction” containing
bisulfite and in ten real samples of
different wines, using a methodology
developed and validated to analyze them simultaneously. This
methodology is based on HPLC with
binary gradient system of elution.
On the basis of Principal Component Analysis (PCA) and
dissociation constants (K
d
), the results revealed that aliphatic aldehydes
form adducts with S(IV), whereas ketones, cyclic aldehydes and trans-
alkenes interact weakly and are found predominantly in their free form.
These results revealed also that pH 10 and 11 were defined as the most
appropriate for CC-S(IV)
adduct dissociation and the total CCs were
quantified reliably. In the wines and grapes studied were identified
formaldehyde, acetaldehyde, butanal,
hexanal, furfural, benzaldehyde,
cyclo hexanone,
E
-pent-2-en-1-al, and 2-ethil hexanal, being the last one
firstly identified in wines. Formald
ehyde, acetaldehyde, butanal, and
hexanal can be considered primary aroma since they are present in wines
as well in their respective grapes.
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Estudo de compostos carbonílicos e os respectivos ácidos hidroxialquilsulfônicos em vinhosAzevedo, Luciana Cavalcante de January 2007 (has links)
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Luciana.pdf: 1586143 bytes, checksum: a57cce30857cde7aaf0e0e909a4950aa (MD5)
Previous issue date: 2007 / A análise dos compostos carbonílicos (CCs) é um dos procedimentos de rotina em muitos laboratórios de controle de qualidade de bebidas, no entanto, atualmente são quantificados apenas os CCs totais expressos em teores de acetaldeído, sem que sejam associados outros CCs com a sua qualidade. Esses compostos possuem impacto olfativo no aroma dos vinhos e uma forte afinidade pelo bissulfito, adicionado na vinificação, podendo formar adutos estáveis que interferirão também no aroma. Os maiores desafios, no entanto, consistem em predizer quais CCs têm maior afinidade pelo S(IV), que circunstâncias favorecem esta interação e como analisá-los em conjunto. Por esse motivo, no presente estudo foi avaliado o perfil de 22 CCs em “solução modelo" e em dez amostras reais de vinhos, empregando uma metodologia desenvolvida e validada para analisá-los de forma simultânea, que utiliza CLAE com sistema de gradiente binário de eluição. Baseado na Análise de Componentes Principais (ACP) e nas constantes de dissociação (Kd), os resultados revelaram que os aldeídos alifáticos formam adutos com S(IV), enquanto as cetonas, os aldeídos cíclicos e os trans-alcenais interagiram fracamente e são encontrados predominantemente em sua forma livre. Estes resultados revelaram também que a faixa de pH entre 10 e 11 foi definida como a mais apropriada para a dissociação do aduto CC-S(IV), favorecendo a quantificação segura dos CCs na forma total. Nos vinhos e uvas estudados foram identificados o formaldeído, acetaldeído, butanal, hexanal, furfural, benzaldeído, E-penten-2-al, ciclo hexanona e 2-etil hexanal, sendo este último identificado pela primeira vez neste tipo de matriz. Os quatro primeiros aldeídos citados podem ser considerados aromas primários por estarem presentes tanto nos vinhos quanto nas uvas que lhes deram origem. / Salvador
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Análise exploratória multivariada empregando o perfil cromatográfico de compostos carbonílicos na atmosfera da cidade de São Paulo / Multivariate analysis using the entire chromatographic profile of carbonyl compounds in the air of São Paulo cityAndré Marcelo de Souza 25 February 2010 (has links)
Na última década, a utilização de misturas de gasolina e etanol em qualquer proporção como combustível em veículos do tipo “flex” aumentou de forma significativa no Brasil. Compostos Carbonílicos (CC) pertencem a uma importante classe de poluentes emitidos pela frota veicular. A cidade de São Paulo, Brasil, tem 9,2 milhões de veículos, os quais afetam diretamente a qualidade do ar. Neste trabalho, foi determinada a concentração de quatorze CC na atmosfera, em três diferentes sítios de amostragem localizados na zona oeste da cidade de São Paulo, dois nos campus da Cidade Universitária: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG) e Instituto de Ciências Biomédicas (ICB) e um em Cerqueira César, Faculdade de Saúde Pública (FSP), no período de 2008/2009. Os CC foram coletados em cartucho de sílicagel, impregnada com 2,4-dinitrofenilhidrazina e analisados por Cromatografia Líquida de Alta Eficiência (CLAE) com detecção UV-visível. O conjunto de dados gerado foi caracterizado aplicando Análise de Componentes Principais (PCA) e Análise de Agrupamentos Hierárquicos (HCA). Foi utilizado o cromatograma completo, uma abordagem quimiométrica ainda não utilizada para avaliação de CC na atmosfera. Os cromatogramas das amostras foram alinhados utilizando os algoritmos Peakmatch e Optim_COW, deslocamentos de linha base e ruído foram removidos empregando, respectivamente, a primeira derivada e o método de ajuste polinomial de Savitzky- Golay. As amostras coletadas nos três sítios apresentaram contrações significativas de formaldeído (F), acetaldeído (A) e acetona e concentrações menores de butiraldeído, benzaldeído, valeraldeído e propionaldeído. A quantidade de acetaldeído foi superior à de formaldeído para a maioria das amostras, levando a uma razão F/A menor do que 1, fato que tem sido atribuído ao uso de etanol em larga escala como combustível veicular. Na análise univariada, foi observado um perfil semelhante nos gráficos de concentração dos CC em qualquer um dos sítios de amostragem. Na análise multivariada por PCA, a PC1 representou a quase totalidade da variação experimental (97,6%). Estes resultados podem sugerir a presença de uma única fonte de emissão. O gráfico de scores da PCA e o dendograma da HCA indicaram a formação de dois agrupamentos: um formado pelas amostras FSP e IAG e outro pelas amostras ICB. O gráfico de loadings da PCA indicou que as diferenças são devidas à concentração de todos os CC. A separação das amostras ICB das demais pode ser explicada pelas diferentes condições meteorológicas observadas no sítio ICB / In the last decade, the use of ethanol-blended-gasoline in any proportion as fuel in light vehicles (flex fuel) has significantly increased in Brazil. Carbonyl compounds (CC) are an important class of vehicular total hydrocarbons emission. São Paulo City, Brazil, has 9,2 million vehicles that directly affect the air quality. In this work, the concentration of fourteen CCs in the air of three different sites of São Paulo city was determined during 2008/2009. Two sites (IAG and ICB) were located inside São Paulo University whereas a third one was located in Cerqueira César (FSP). Compounds were collected in a silica-gel cartridge coated with 2,4-dinitro-phenylhydrazine and analyzed by CLAE with UV-Vis detection (365 nm). The sites were characterized by Principal Component Analysis (PCA) and Hierarquical Cluster Analysis (HCA). The entire chromatogram was used to multivariate calculations, which represents an innovative approach in CC studies. Chromatograms of the samples were aligned using the Optim_COW and Peakmatch algorithms, the baseline was corrected by the first derivative and instrumental noise was removed by Savitzky-Golay polynomial fit. The samples collected at the three sites presented different amounts of formaldehyde (F), acetaldehyde (A) and ketone and minor concentrations of butiraldehyde, benzaldehyde, valeraldehyde and propionaldehyde. The acetaldehyde content was observed to be superior to the formaldehyde, so that the F/A was lower than 1 for all sites. This fact can be related to the increasing use of ethanol as fuel. It was observed a similar profile of CC concentration in all sites studied. In PCA analysis, only one Principal Component could describe a large amount of experimental variability (97.57 %), indicating that a single emission source (vehicular) might have been present. The PCA scores graph and HCA dendogram pointed out that samples from FSP and IAG were similar whereas samples from ICB presented a different behavior. The loadings graph indicated that those differences were due to concentration of all CC. This fact could be due to different climatic conditions during sampling
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