Performance of Different Immobilized Lipases in the Syntheses of Short- and Long-Chain Carboxylic Acid Esters by Esterification Reactions in Organic Media

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

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Chemodynamics, transport behaviour and treatment of phthalic acid esters in municipal landfill leachates

Water Science & Technology ◽

10.2166/wst.1998.0135 ◽

1998 ◽

Vol 38 (2) ◽

pp. 185-192 ◽

Cited By ~ 24

Author(s):

M. J. Bauer ◽

R. Herrmann ◽

A. Martin ◽

H. Zellmann

Keyword(s):

Particulate Matter ◽

Aquatic Environment ◽

Phthalic Acid ◽

Phthalic Acid Esters ◽

Landfill Leachates ◽

Transport Behaviour ◽

Ethylhexyl Phthalate ◽

Dissolved Phase ◽

Acid Esters ◽

Long Chain

Large amounts of phthalic acid esters (PAEs) are leached from plastics dumped at municipal landfills. This leachate transports PAEs either adsorbed on particulate matter or in dissolved phase. Dissolved organic macromolecules, mainly humic-like substances, enhance the solubility of PAEs. In the biochemical environments of municipal landfills short chain PAEs can be degraded by base-catalyzed hydrolysis or by microorganisms which enzymatically split the side chains. However, there is no cleavage of the aromatic ring. Long chain PAEs like di-(2-ethylhexyl) phthalate are neither degraded abiotically nor by microorganisms. Hence, these PAEs can be leached and washed out of leaky landfills into the groundwater and thus continue to be a threat to the aquatic environment. Only a combined UV radiation/ozonation treatment is capable of fully destroying PAEs.

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The mechanism of alkylation of benzene with carboxylic acid esters induced by titanium tetrachloride

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19762878 ◽

1976 ◽

Vol 41 (10) ◽

pp. 2878-2884 ◽

Cited By ~ 1

Author(s):

K. Mach ◽

E. Drahorádová

Keyword(s):

Carboxylic Acid ◽

Titanium Tetrachloride ◽

Alkylation Of Benzene ◽

Acid Esters

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The occurrence of long chain polyprenols in leaves of plants of Rosaceae family and their isolation by time-extended liquid chromatography

Biochemistry and Cell Biology ◽

10.1139/o92-068 ◽

1992 ◽

Vol 70 (6) ◽

pp. 448-454 ◽

Cited By ~ 9

Author(s):

Ewa Świeżewska ◽

T. Chojnacki ◽

W. J. Jankowski ◽

K. Singh ◽

J. Olsson

Keyword(s):

Liquid Chromatography ◽

Fatty Acid ◽

Large Scale ◽

Fatty Acid Esters ◽

Large Scale Preparation ◽

Scale Preparation ◽

Wet Weight ◽

Rosaceae Family ◽

Acid Esters ◽

Long Chain

The long chain polyprenols composed of 30 and more isoprene units from leaves of plants belonging to the genera Potentilla and Rosa have been described. They occur in the form of fatty acid esters. The composition of polyprenol mixture was species dependent and its content reached ca. 0.5% wet weight. Large scale preparation of individual polyprenols from a natural polyprenol mixture was performed using time-extended liquid chromatography on the hydrophobic gel Lipidex-5000.Key words: long chain polyprenols, Rosaceae.

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