A Practical and Highly Chemoselective
Hydrogenation of Aldehydes with a Copper Catalyst
作者:Hideo Shimizu、Noboru Sayo、Takao Saito
DOI:10.1055/s-0028-1216726
日期:——
A practical hydrogenation of aldehydes mediated by an inexpensive and easily available base metal, copper, is reported. A copper complex associated with 1,4-bis(diphenylphosphino)butane (DPPB) hydrogenates α,β-unsaturated aldehydes in a highly chemoselective fashion to give allylic alcohols with improved catalytic productivities. The reaction system was also effective for the conversion of simple aldehydes
Formation of fluorescent compounds in the reaction of butyraldehyde and methylamine at pH 7 and 37°C was investigated as a model of the reaction of xidized lipids and proteins. The reation mixture was treated with borohydride for isolation of the products. Some fluorescent products remained unchanged and the other changed into other fluorescent compounds. One of the fluorescent compounds produced on borohydride treatment was identified as 2, 4-diethyl-2, 5-dihydrofuran, which exhibited fluorescence with an excitation maximum at 345nm and an emission maximum at 406nm. The product may be derived by the condensation of 2 molecules of butyraldehyde in the presence of methylamine. Non-fluorescent products composed of 2 : 1, 3 : 1 and 4 : 1 ratios of butyraldehyde and mehylamine were isolated. The fluorescent products may include self-condensation products of butyraldehyde formed in the presence of methylamine.
A convenient approach to (S)-2-ethylhexan-1-ol mediated by baker’s yeast
作者:Yikang Huang、Fanglin Zhang、Yuefa Gong
DOI:10.1016/j.tetlet.2005.08.063
日期:2005.10
The baker’s yeast (Saccharomyces cerevisiae) mediated asymmetric bioreduction of 2-ethylhex-2-enal (1) went smoothly under a mild condition and afforded a high yield of (S)-2-ethylhexan-1-ol (2a) with excellent enantioselectivity in biphasic system.
The synthesis and surfactant behaviour of two series of sulfosuccinic diesters, AOT-related compounds, are described [Aerosol-OT 1: sodium bis(2-ethylhexyl) sulfosuccinate]. The first family contains unsaturated, racemic or enantiopure, 2-ethylhex(en)yl chains with various positions of the double bond. These compounds are readily prepared from the corresponding unsaturated alcohol by the standard two-step procedure; their critical micelle concentrations are higher than those of normal AOT and depend on the position of the double bond. The second series consists of nonsymmetric homologues with two different substituents: various unsymmetrical sulfosuccinic diesters with two enantiopure saturated or unsaturated chains of opposite configuration, or with two different substituents like methyl and 2-ethylhexyl, hydrogenated and deuterated chains as well as saturated and unsaturated chains are described. These unsymmetrical sulfosuccinic diesters are readily obtained in a three-step synthetic procedure involving the regiospecific sulfonation of maleic monoester in aqueous medium. The structure of the sodium 4-alkyl-2-sulfosuccinic acid key intermediate is unambiguously resolved by NMR comparative analysis of the hydrogenated and deuterated derivatives. The surfactant behaviour of some unsymmetrical compounds is studied.
[EN] USE OF EPOXIDES AS FUNGICIDES<br/>[FR] UTILISATION D'EPOXIDES EN TANT QUE FONGICIDES
申请人:VALTION TEKNILLINEN
公开号:WO2005089549A1
公开(公告)日:2005-09-29
The present invention relates to the use of one or more epoxides as mould preventive agents, the epoxide being an aliphatic epoxide ester or ether or glycidyl ester or ether, and to a method for preventing mould buildup.