ChemInform Abstract: Bifunctional Heterogeneous Catalysis of Silica—Alumina-Supported Tertiary Amines with Controlled Acid—Base Interactions for Efficient 1,4-Addition Reactions.

ChemInform ◽  
2010 ◽  
Vol 41 (5) ◽  
Author(s):  
Ken Motokura ◽  
Satoka Tanaka ◽  
Mizuki Tada ◽  
Yasuhiro Iwasawa
1980 ◽  
Vol 45 (2) ◽  
pp. 406-414 ◽  
Author(s):  
Jiří Svoboda ◽  
Oldřich Paleta ◽  
Václav Dědek

Dimerisation of trifluoropropenenitrile (I) in the presence of potassium fluoride and tertiary amines afforded a mixture of stereoisomeric perfluoro-4-methyl-pentenedinitriles (II), higher-boiling compounds, and 2,3,3,3-tetrafluoropropanenitrile (III) which arises by proton transfer from the solvent molecule. Under optimum conditions, product II was obtained in about 50% yield. Reaction of the nitrile I with methyl trifluoropropenoate (IV) gave, besides the dimers II and V, the product of addition of the nitrile I to the propenoate, IV, i.e. methyl 4-cyanoperfluoro-2-pentenoate (VI), and the addition product of the propenoate IV to the nitrile I, i.e. methyl 4-cyanoperfluoro-2-methyl-3-butenoate (VII). The relative reactivity if I and IV is discussed. The ratio of stereoisomers in II, V, VI and VII indicates that the magnitude of the steric substituent effect, operating in the reaction mechanism, decreases in the order -CFCF3.(COOCH3) > -CFCF3(CN) > -COOCH3 > -CN.


The development of an ‘on-line’ computer for use with a combined gas chromatographymass spectroscopy (g.c.-m.s.) technique in the study of heterogeneous catalysis is described and discussed with reference to the reactions of ethylene and deuterium on oxides. Emphasis has been placed on the selectivities shown by a number of catalysts for the exchange and addition reactions. Magnesium oxide effects the exchange of ethylene without production of ethane even at 671 K; y-alumina also exhibits a high selectivity for exchange. In contrast, on chromium oxide (Cr20 3) at 197 K and zinc oxide at 273 K, ethylene undergoes rapid deuteration with no observable exchange of the olefin. For the range of catalysts studied the ratio of rate constants for the exchange and addition reactions decreases in the order: MgO > Al 2 O 3 > TiO 2 ~ Fe 2 O 3 > Co 3 O 4 > ZrO 2 > ZnO ~ Cr 2 O 3 . An explanation for the marked differences in catalytic behaviour within this group of oxides is provided.


ChemInform ◽  
2010 ◽  
Vol 32 (42) ◽  
pp. no-no
Author(s):  
Antonio de la Hoz ◽  
Angel Diaz-Ortiz ◽  
Maria Victoria Gomez ◽  
Antonio Mayoral ◽  
Andres Moreno ◽  
...  

Tetrahedron ◽  
2001 ◽  
Vol 57 (25) ◽  
pp. 5421-5428 ◽  
Author(s):  
Antonio de la Hoz ◽  
Angel Dı́az-Ortiz ◽  
Marı́a Victoria Gómez ◽  
José Antonio Mayoral ◽  
Andrés Moreno ◽  
...  

ChemInform ◽  
2011 ◽  
Vol 42 (19) ◽  
pp. no-no
Author(s):  
M. Caterina Lubinu ◽  
Lidia De Luca ◽  
Giampaolo Giacomelli ◽  
Andrea Porcheddu

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1009 ◽  
Author(s):  
Huancong Shi ◽  
Min Huang ◽  
Qiming Wu ◽  
Linna Zheng ◽  
Lifeng Cui ◽  
...  

Studies of catalytic CO2 absorption and desorption were completed in two well-performed tertiary amines: diethylmonoethanolamine (DEEA) and 1-dimethylamino-2-propanol (1DMA-2P), with the aid of CaCO3 and MgCO3 in the absorption process, and with the aid of γ-Al2O3 and H-ZSM-5 in the desorption process. The batch process was used for CO2 absorption with solid alkalis, and the recirculation process was used for CO2 desorption with solid acid catalysts. The CO2 equilibrium solubility and pKa were also measured at 293 K with results comparable to the literature. The catalytic tests discovered that the heterogeneous catalysis of tertiary amines on both absorption and desorption sides were quite different from monoethanolamine (MEA) and diethanolamine (DEA). These results were illustrative as a start-up to further study of the kinetics of heterogeneous catalysis of CO2 to tertiary amines based on their special reaction schemes and base-catalyzed hydration mechanism.


2010 ◽  
Vol 17 (1) ◽  
pp. 82-85 ◽  
Author(s):  
M. Caterina Lubinu ◽  
Lidia De Luca ◽  
Giampaolo Giacomelli ◽  
Andrea Porcheddu

Sign in / Sign up

Export Citation Format

Share Document