Homogeneous hydrogenation and deuteration of pentacyclic triterpenoids: Double bonds in side-chains

The reduction of terminal double bonds in the side chains on the rings A and E of pentacyclic triterpenoids by means of tris(triphenylphosphine)rhodium chloride permits selective reduction of dienes and labelling with deuterium with a low scattering. The effect of the amount of the catalyst and the solvent used on the rate of reduction was studied in the case of 3β,28-diacetylbetulin.

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In Situ Generation and Synthetic Application of 2-Phenylbenzimidazoline to the Selective Reduction of Carbon–Carbon Double Bonds of Electron-Deficient Olefins

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.60.737 ◽

1987 ◽

Vol 60 (2) ◽

pp. 737-746 ◽

Cited By ~ 66

Author(s):

Hidenori Chikashita ◽

Shuichi Nishida ◽

Makoto Miyazaki ◽

Yasuhiro Morita ◽

Kazuyoshi Itoh

Keyword(s):

Selective Reduction ◽

Double Bonds ◽

In Situ Generation ◽

Synthetic Application

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Selective reduction of conjugated double bonds with molecular hydrogen and palladium(II) complexed to ferrocenylamine sulfide catalysts

Tetrahedron Letters ◽

10.1016/0040-4039(91)80065-e ◽

1991 ◽

Vol 32 (40) ◽

pp. 5489-5492 ◽

Cited By ~ 12

Author(s):

Hussein M. Ali ◽

Ahmad A. Naiini ◽

Carl H. Brubaker

Keyword(s):

Molecular Hydrogen ◽

Selective Reduction ◽

Sulfide Catalysts ◽

Double Bonds

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ChemInform Abstract: 3-Butyl-1-methylimidazolinium Borohydride ([bmim][BH4]) - A Novel Reducing Agent for the Selective Reduction of Carbon-Carbon Double Bonds in Activated Conjugated Alkenes.

ChemInform ◽

10.1002/chin.200908046 ◽

2009 ◽

Vol 40 (8) ◽

Author(s):

Jiayi Wang ◽

Gonghua Song ◽

Yanqing Peng ◽

Yidong Zhu

Keyword(s):

Selective Reduction ◽

Reducing Agent ◽

Double Bonds

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Selective reduction of carbon-carbon double bonds of aryl substituted chalcones with Zn/CH3COONH4/C2H5OH/H2O

Journal of Chemical Research ◽

10.3184/030823404323000404 ◽

2004 ◽

Vol 2004 (2) ◽

pp. 118-119 ◽

Cited By ~ 4

Author(s):

Yong-bo Zhou ◽

Yu-lu Wang ◽

Jin-ye Wang

Keyword(s):

Selective Reduction ◽

Double Bonds

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The Structure of Elastomers and Their Reactivity

Rubber Chemistry and Technology ◽

10.5254/1.3543048 ◽

1951 ◽

Vol 24 (1) ◽

pp. 95-98

Author(s):

A. S. Kuz'minskii ◽

N. N. Lezhnev

Keyword(s):

Molecular Weight ◽

Methyl Groups ◽

Side Chains ◽

Double Bonds ◽

Gutta Percha ◽

Different Temperatures ◽

Spatial Configurations ◽

The Mean ◽

Kinetics Of ◽

Mean Molecular Weight

Abstract It has not yet been ascertained what constituent parts within the structure of various elastomers have the greatest influence on the reactivity of the elastomers. There are indications that the side chains, the presence of methyl groups acting as substitutes, and differences in spatial configurations, etc., all have definite effects. The present authors have investigated the oxidation of several different elastomers at different temperatures. The experiments were carried out both in the presence and in the absence of an inhibitor (phenyl-β-naphthylamine). The elastomers and the inhibitor were first carefully purified. The kinetics of autoxidations were studied volumetrically by means of an apparatus already described by one of the authors. A chainless molecular introduction of oxygen into the double bonds of the elastomer in the presence of the inhibitor was studied with the aid of our own previously described inhibitor methods. The study included the oxidation of butadiene elastomers containing different distributions of double bonds in the main and side chains, divinylstyrene rubber, and the hydrocarbons of natural rubber and gutta-percha. These products are distinguished by their different degrees of unsaturation, the number of side chains, the number of double bonds in both their main and side chains, the length of their molecular chains (the mean molecular weight), and their spatial configurations.

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