Synthesis of mono- and diacetylenic derivatives of silylferrocene

1984 ◽  
Vol 49 (9) ◽  
pp. 2111-2115 ◽  
Author(s):  
Abdel Ghani Ali El-Agamey ◽  
Levan P. Asatiani
Keyword(s):  
Low Temperature ◽  
Catalytic Hydrogenation ◽  
Derivatives Of ◽  
Acetylenic Compounds

1-Ferrocenyl(methyl)phenylsilane (I) was prepared by silylation of ferrocene at low temperature. Mono- and diacetylenic compounds of silyferrocene were prepared by the interaction of chloroferrocenylsilane with mono- and dilithium acetylenic derivatives, respectively. It has been found that, catalytic hydrogenation of the prepared acetylenic compounds seem to be totally determined by steric considerations.

The Through-Bond Interaction of a Sulfur Lone Pair with Oxygenated Substituents in the Thiacyclohexane Framework

2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Crystal Structures ◽  
Bond Distance ◽  
Lone Pair ◽  
X Ray ◽  
Ester Derivative ◽  
Bond Interaction ◽  
Derivatives Of ◽  
Electron Demand

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.

Selective catalytic hydrogenation of unsaturated derivatives of nitrobenzene in alcoholic media

1999 ◽  
Vol 144 (1) ◽  
pp. 199-206 ◽  
Author(s):  
E. Lamy-Pitara ◽  
B. N'Zemba ◽  
J. Barbier ◽  
F. Barbot ◽  
L. Miginiac
Keyword(s):  
Catalytic Hydrogenation ◽  
Derivatives Of

Synthesis of 5'-O-phosphonomethyl derivatives of pyrimidine 2'-deoxynucleosides

1990 ◽  
Vol 55 (10) ◽  
pp. 2521-2536 ◽  
Author(s):  
Marcela Krečmerová ◽  
Hubert Hřebabecký ◽  
Antonín Holý
Keyword(s):  
Sodium Salt ◽  
Catalytic Hydrogenation ◽  
Bond Cleavage ◽  
Diethyl Ester ◽  
Derivatives Of

Reaction of sodium salt of 3-N,3'-O-bis(benzyloxymethyl)-2'-deoxyuridine (X) and 3-N,3'-O-bis(benzyloxymethyl)-2'-deoxythymidine (XI) with diethyl p-toluenesulfonyloxymethanephosphonate in dimethylformamide afforded diesters of the respective 5'-O-phosphonomethyl derivatives XII and XVII. Diethyl esters of 5'-O-phosphonomethyl-2'-deoxynucleosides XV and XIX, obtained after hydrogenolytic removal of the benzyloxymethyl groups, were converted into free 2'-deoxy-5'-O-phosphonomethyluridine (XVI) and a mixture of anomeric 1-(2-deoxy-5-O-phosphonomethyl-β-D-erythro-pentofuranosyl)thymines (XXIIIa, XXIIIb), respectively. Analogously, 2'-deoxy-5'-O-phosphonomethylcytidine (XXXIV) was prepared from 4-N-benzoyl-2'-deoxy-3'-O-(tetrahydro-2H-pyran-2-yl) cytidine (XXX) via diethyl ester of 2'-deoxy-5'-O-phosphonomethylcytidine (XXXIII). This compound reacted with bromotrimethylsilane to give compound XXXIV without anomerization and nucleoside bond cleavage. Condensation of the protected nucleosides X and XI with dibenzyl p-toluenesulfonyloxymethanephosphonate afforded dibenzyl esters of the corresponding 5'-O-phosphonomethyl derivatives XIII and XVIII. The free 5'-O-phosphonomethyl derivatives XVI and XXIIIa were obtained from XIII and XVIII by catalytic hydrogenation.

scholarly journals Preparation, structure, and conformation in solution of diacetyl derivatives of 6,7-dimethyl-1,4-dihydroquinoxaline and of dihydropyridotriazines

1985 ◽  
Vol 63 (11) ◽  
pp. 3210-3215 ◽  
Author(s):  
Joseph Armand ◽  
Line Boulares ◽  
Marie-Paule Simonnin ◽  
Christian Bellec ◽  
Odile Convert ◽  
...  
Keyword(s):  
Low Temperature ◽  
Conformational Study ◽  
Derivatives Of

A conformational study of 1,4-diacetyl-1,4-dihydro-6,7-dimethylquinoxaline is carried out by low temperature nmr in CD2Cl2. Important acetyl rotation induced shifts have been observed for the peri and ortho protons. These results, together with low temperature nOe experiments, permit the determination of the structures and conformations of four diacetyl derivatives of dihydropyrido[3,4-e] as-triazines and of one diacetyl derivative of a dihydropyrido[4,3-e] as-triazine.

Formaldehyde production via hydrogenation of carbon monoxide in the aqueous phase

2015 ◽  
Vol 17 (6) ◽  
pp. 3500-3507 ◽  
Author(s):  
Ali Mohammad Bahmanpour ◽  
Andrew Hoadley ◽  
Akshat Tanksale
Keyword(s):  
Carbon Monoxide ◽  
Low Temperature ◽  
Aqueous Phase ◽  
Catalytic Hydrogenation ◽  
Formaldehyde Production ◽  
Hydrogenation Of Carbon Monoxide

Discovery of a low temperature route to produce formaldehyde via catalytic hydrogenation of carbon monoxide in the aqueous phase.

scholarly journals Selective Formation of Epoxylimonene Catalyzed by Phosphonyl/Arsoníyl Derivatives of Trivacant Polyoxotungstates at Low Temperature

2020 ◽  
Vol 2020 (7) ◽  
pp. 596-596
Author(s):  
Ourania Makrygenni ◽  
Louise Vanmairis ◽  
Sabrina Taourit ◽  
Franck Launay ◽  
Alain Shum Cheong Sing ◽  
...  
Keyword(s):  
Low Temperature ◽  
Derivatives Of ◽  
Selective Formation

Application of the Variable Oxygen Probe to Determine the π-Electron Donor Ability of the Alkyne Group

2014 ◽  
Vol 67 (12) ◽  
pp. 1866 ◽  
Author(s):  
Benjamin L. Harris ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Electron Donor ◽  
Oxygen Probe ◽  
X Ray ◽  
X Ray Crystallography ◽  
Donor Ability ◽  
Structural Database ◽  
Derivatives Of ◽  
Electron Demand ◽  
Electron Donor Ability

Eight ester and ether derivatives of propargyl alcohol with varying electron demand were structurally characterised using low temperature X-ray crystallography, these were combined with seven derivatives obtained from the Cambridge Structural Database. Variable oxygen probe analysis of these derivatives provided evidence that the ethynyl substituent is a relatively weak π-electron donor, and is a slightly less effective donor than the C–C bond of an ethyl substituent.

scholarly journals Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

2017 ◽  
Vol 13 ◽  
pp. 579-588 ◽  
Author(s):  
Jan Szabo ◽  
Julian Greiner ◽  
Gerhard Maas
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Nitrogen Atom ◽  
Catalytic Hydrogenation ◽  
Acid Chlorides ◽  
Reaction Conditions ◽  
Derivatives Of ◽  
Guanidinium Salts ◽  
Triazolium Salts

Depending on the reaction conditions, N,N’,N’’-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form either symmetrical N,N’,N’’-tris(N-acyl-N-benzylamido)guanidines 6 or mesoionic 4-amino-1,2,4-triazolium-3-hydrazinides 7. The latter were converted into 1,2,4-triazolium salts by protonation or methylation at the hydrazinide nitrogen atom. Neutral 1,2,4-triazoles 10 were obtained by catalytic hydrogenation of an N-benzyl derivative. Crystal structure analyses of a 4-benzylamino-1,2,4-triazolium-3-hydrazinide and of two derived 1,2,4-triazolium salts are presented.

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