• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.29-30
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• 2007

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.865-868
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• 1994

In the presence of stoichiometric (-)-${\alpha}$-isosparteine, 2-lithio-1,3-dithiane underwent enantioselective addition to aldehydes with moderate ee's (6-70%).

• Bulletin of the Korean Chemical Society
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• v.17 no.12
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• pp.1135-1142
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• 1996

Reaction of diethylzinc with α-branched aldehydes in the presence of a catalytic amount (5 mol %) of various β-amino thiols in toluene or ether provided the corresponding secondary alcohols in outstanding ee. Detailed preparative procedure for the β-amino thiols are presented.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.517-525
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• 2009

We measured ambient concentrations of hazardous air pollutants such as volatile organic compounds (VOCs) and aldehydes in residential areas nearby small and medium scale shipbuilding companies. The VOC concentrations were higher during the normal operation periods than vacation at which almost all operations were shutdown. Concentrations of VOCs was higher, as the sampling site was nearer from shipbuilding companies. The major components of VOCs were m,p-xylene, ethylbenzene, o-xylene, toluene, and 1,3,5-trimethylbenzene which had been found as major VOC compounds emitted from painting processes of shipbuilding in the previous studies. The major components of aldehydes analyzed were benzaldehyde, acrolein, formaldehyde, and acetaldehyde. The concentration of aldehydes was highest at the furthest sampling point from shipbuilding companies because the formation of aldehyde compounds could be occurred by the secondary chemical reactions of VOCs. The results of this study shows a proper counterplan need to be established for the reduction of hazardous air pollutants emitted from small and medium scale shipping companies.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1654-1658
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• 2014

High value-added aromatic aldehydes (e.g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide ($H_2O_2$) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin ($Co(TPPS_4)$) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without $Co(TPPS_4)$. Moreover, a possible mechanism of HFBO oxidation using $Co(TPPS_4)/H_2O_2$ was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under $Co(TPPS_4)/H_2O_2$ system.

• Journal of Environmental Science International
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• v.29 no.6
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• pp.673-682
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• 2020

This study investigates the concentration distribution of aldehydes and volatile organic compounds (VOCs) in the archive of the National Library in Korea and evaluates the health risks to workers from hazardous chemicals. Acetaldehyde had the highest concentration among the nine species of aldehydes present in the archive and the concentration of toluene was the highest among the six species of VOCs. Most of the detected substances showed that their indoor concentrations were higher than the outdoor ones, suggesting the possibility of indoor sources of aldehydes and VOCs. The evaluation of health risks for workers based on these measurement results showed that not all substances were hazardous to the human body. However, considering the possibility of the presence of indoor sources and the potential limits of our study owing its short period, it is necessary to conduct long-term studies on the concentration distribution of indoor pollutants in the archive environment.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.474-486
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• 2019

Objectives: This study was performed to investigate the emission characteristics of aldehydes emitted by the printing industry and to evaluate their impact on adjacent residential areas. Methods: Aldehydes and THC were measured from the front of the control device in the printing and coating process. Aldehydes and ketones were measured by workplace area, residential area, and background area to evaluate their impact. Results: The concentrations of formaldehyde (<0.047 ppm) and acetaldehyde (<0.068 ppm) in the printing and coating process were relatively low, and the methyl ethyl ketone used as the primary solvent was the main carbonyl compound in the printing process. The daily mean concentrations of formaldehyde and acetaldehyde were not significantly different by workplace area, residential area, or background area. However, the concentration of methyl ethyl ketone was high in the order of workplace area, residential area, and background area. Conclusions: The concentrations of formaldehyde and acetaldehyde in the adjacent residential areas are considered to be more influenced by secondary sources of photochemical reactions than by primary sources. Methyl ethyl ketone is considered to be highly influenced by the primary source, which is printing facilities.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2691-2696
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• 2013

The electronic cigarette (E-cigarette) is a battery-powered device that aerosolizes nicotine so that it is readily delivered into the respiratory tract. The analytical data regarding the substances present in E-cigarettes are very limited. The aim of this study was to measure the concentration of aldehydes-formaldehyde (FA), acetaldehyde (AA) and, acrolein (AL)-in 225 replacement liquid brands from 17 E-cigarette shops sold in the Republic of Korea by headspace solid-phase micro extraction and gas chromatography-mass spectrometry (HS-SPME GC-MS). The concentration range of FA and AA was 0.02-10.09 mg/L (mean = 2.16 mg/L, detected in 207 of 225 samples) and 0.10-15.63 mg/L (mean = 4.98 mg/L, detected in all samples), respectively. AL was not detected in any of 225 replacement liquids. FA and AA were originally present in almost all replacement liquids of electronic cigarettes.

• Journal of the Korean Chemical Society
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• v.51 no.5
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• pp.418-422
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• 2007

A simple and high yielding one-pot method for synthesis of 2,4,5-triarylimidazoles from condensation of benzoin or benzil, ammonium acetate and aromatic aldehydes using sulphanilic acid catalyst is described. The lower priced catalyst, higher yields and shorter reaction time are the advantages of the presented method.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.715-720
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• 2014

A Cu(II) complex with an three nitrogens and one sulfur coordination environment was synthesized and characterized. Its redox potential was observed at 0.483 V vs. NHE, very similar to that of a Cu-containing fungal enzyme, galactose oxidase, which catalyzes the oxidation of alcohols to corresponding aldehydes with the concomitant reduction of molecular oxygen to water. The Cu(II) complex selectively oxidizes the benzylic alcohols using TEMPO/$O_2$ under mild reaction conditions to corresponding aldehydes without forming any over-oxidation product. Moreover, the catalyst can be recovered and reused multiple times for further oxidation reactions, thus minimizing the waste generation.