Réaction d'énamines dérivées de la cyclohexanone avec le tétracyanoéthylène

Reaction with Tetracyanoethylene of Enamines derived from Cyclohexanone At room temperature enamines of cyclohexanone react with tetracyanoethylene (TCNE) to give substituted tetrahydroindenes 5 . The structures are assigned on the basis of ¹³C-NMR. data and confirmed by hydrolysis. Spectroscopic studies (IR., UV., ESR.) at different temperatures indicate that the reaction can follow two routes: classical zwitterion formation, or a concurrent electron transfer between the enamines and TCNE leading to the derivates 5 . These are the first reported examples of the γ-carbon reactivity of an enamine.     

Action du chlorure de nitrosyle sur le trichloréthylène et sur le tétrachloréthylène

Nitrosyl chloride is only chlorinating in darkness and above 100°. In the sun light and at room temperature it reacts as a chlorinating, nitrosating, nitrating and oxidizing agent. With trichlorethylene in fact pentachlorethane 1,1,1,2-tetrachloro-2-nitrosoethane, 1,1,1,2-tetrachloro-2-nitroethane, dichloracetic acid and a compound of empirical formula C₄H₂Cl₅NO₂ are obtained. Tetrachloroethylene carried to hexachlorethane, pentachloronitrosoethane and tetrachloro-2-(pentachlorethyl)-1,2-oxazetidine. Introduced nitrosyl chloride provided nitrogen monoxide prouved by gaz chromatography. This monoxide reacted afterwards to give nitrogen which is the single nitrogenous gazeous compound. Carbondioxide is a minor component of the gaz.     

Etude de la réaction de l'acétylacétone avec les diamines hétéroaromatiques

The inluence of the starting o-diamine on the reaction products is shown in the condensation of heteroaromatic o-diamines with acetylacetone; 2,3- and 3,4-diaminopyridines gave only a crotonic intermediate providing imidazopyridines. On the other hand, 1,5-diaminoimidazoles gave tow types of compounds, imidazotriazepines and imidazopyridines. Triazolopyridazines were formed from 3,4-diaminotriazoles.     

Action du monoxyde d'azote sur le trichloréthylène et sur le tétrachloréthylène

The Action of Nitrogen Monoxide on Trichloro-and Tetrachlor-Ethylene . Under the sun light and at room temperature nitric oxide reacts with trichlorethylene and tetrachlorethylene giving monomer nitroso nitrated compounds. These compounds can also be obtained through reaction of dinitrogen trioxide with trichlorethylene and tetrachlorethylene. The nitrating and oxidizing properties of nitric oxide can be considered through these reactions: – Trichlorethylene leads to: pentachlorethane,1,1,1,2-tetrachlor-2-nitroethane, dichloracetic acid and 1,1,3,3-4-pentachloro-4-nitro-1-butene: CO₂ and CO are also observed. –Tetrachlorocthylene gives : hexachlorethane, tetrachloro-2pentaclorethyl-1,2-oxazetidine; carbon tetrachlorid and trichloracetylchlorid arc obtainetl in very little yiclcl. These results prove that oxidizing cleavage may occur. Kitric oxitl reacts giving nitrogen as main gazcous product, prouved by gas liquid chrornatography.     

Réaction de l''oxygène singulet avec quelques vinylallènes

The dye sensitized photooxidation of three diversely substituted vinylallenes leads to Δ-4 tetrahydropyrane-3-ones.     

Réaction d'imidoylation: Réactivité de composés à méthylène actif avec les O-ethylcarbamates cycliques

Condensation of malononitrile, ethyl cyanacetate and isopropylidene malonate with various O-ethyl cyclic carbamates leads to α-(tetrahydrox- azole-1.3-ylidene-2) and α-(tetrahydroxazine-l,3-ylidene-2)malono- nitriles, ethyl cyanacetates and isopropylidene malonates.     

Fonctionnalisation benzylique en série arène chrome tricarbonyle. Contrôle électronique de la régiospécificité de la réaction

The regiospecificity of the benzylic functional group of arenetricarbonylchromium cannot be explained by preferential attack at the carbon which is eclipsed by the chromium-carbonyl bond. Electronic effects in directing the regiospecificity of benzylic attack was found to predominate.     

Etude de la réactivité de la fonction carbonyle avec le cétène en présence d'un alcoxyde de titane. 1ère communication. Nouvelle méthode de synthèse de β-hydroxyesters

A new synthesis of β-hydroxyesters involving a reaction between a carbonyl compound, ketene and an alkyl-orthotitanate is described. The following carbonyl compounds have been studied: aldehydes, ketones, α-diketones, α- or γ-ketoesters. A reaction mechanism is proposed.     

Synthèse d'amines hétérocycliques,cancérostatiques potentiels

We report the nitration of various heterocycles containing two heterocyclic nitrogen atoms. The amines obtained by reduction have been characterized and the fact that the amines have been tested for anticancer activity is also reported.     

Influence des propriétés intrinsèques de ligands calixaréniques sur des réactions de transformation catalytique de l'éthylène

Influence of the intrinsic properties of calixarene ligands on catalytic reactions involving ethylene. This review shows how the particular structural and chemical properties of calix[4]arene-derived ligands can be exploited in the catalytic transformation of ethylene into dimers, oligomers, and polymers.     

Etude de la réactivité de la fonction carbonyle avec le cétène en présence d'un alcoxyde de titane. 2e communication. A propos de l'interprétation de quelques spectres RMN de β-hydroxyesters formés

The NMR. spectra of a serie of β-hydroxyesters have been studied. It has been found that the methylene protons are magnetically nonequivalent only when the substituents on the center of asymmetry of I or II are very different. The magnetically non-equivalence of the isopropylmethylprotons arise when the β-hydroxyesters contain an aromatic or aromatic conjugated group directly bonded to the asymmetric carbon. The interpretation of this finding is proposed.     

Nouveaux exemples de radicaux libres stables de dérivés hétérocycliques de sucres. Communication préliminaire

Some more examples of stable free radicals of carbohydrate heterocyclic derivatives 2-Glycosyl-4,4,5,5-tetramethylimidazoline- 3-oxide-1-oxyls and 2-glycosyl-4,4,5,5-tetramethylimidazoline 1-oxyls have been prepared in nine carbohydrate series, which proves the generality of the method. The hyperfine coupling constant between the free electron and the α-proton of the glycosyl group is never very large (0-2.3 G) but a correlation between its value and the structure of the aglycone has been noted. Free radicals of that type, stable in aqueous solutions, are potentially interesting for biological studies.     

Catalyseurs Ziegler-Natta supportés sur MgCl2 pour la polymérisation du propène. I. Etude de la réaction entre le triéthylaluminium et le benzoate d'ethyle

In this article we describe a study of the reaction between triethylaluminium (TEA) and ethylbenzoate (BE) in a heptane solution by Fourier transform, infrared (IR), and ultraviolet (UV) spectroscopy. These compounds were chosen as a model of the cocatalytic solution used with a Ziegler-Natta catalyst supported on MgCl₂ for the stereospecific polymerization of propene. In the polymerization concentration range a 2 TEA:1 BE yellow complex was added to the solution and no free BE could be detected at a AI/BE molar ratio above 2: the solution contained only free and complexed TEA. The complex decomposed spontaneously to a colorless aluminium alcoholate. The rate of decomposition remained slow at room temperature and the reaction was enhanced by heating or by a high AI/BE ratio or high AI concentration. The decomposition was inhibited in the presence of an olefin.     

Réactivité d'analogues bihétérocycliques du phénanthrène,vis-à-vis des agents d'acétylation et de lithiation

The influence of annelaction and of the heteroatom upon the reactity of some haterocyclic analogus of phenanthrene with a pyrrole nucleos was tested toward acetylation and lithiation. If methy-l[1]benzofuro-[3,2-b]pyrrole was acetylated only in the 2-position, the sulfer and selenious analogues with [3,2-b] and [2,3-b] annelarion were acetylated in the -2 and -3 position. No reaction at all or only with poor yield (in the oxygenated series) was observed with butyllithium except on the case of l-methyl[1]benzoselenono[2,3-b]pyrrole, where the opening of the selenophene nucleos gives, after carbonation and action of diazomethane, l-methyl-2-methoxycarbony 1-3-(o-methylselenophenyl) pyrrole.     

Synthèse de nouveaux hétérocyeles indoliques

In this work we present a new aproch for the synthesis of tri aned tetracyclic heterocycles in the indole series.     

Sur le mécanisme de la réaction de meth-cohn-tarnowski de préparation des thiocoumarines

Reaction of 2-t-butylthiobenzaldehyde with N-(2-dialkylaminoethyl)-cyanacetamides followed by heating of the resulting 3-(2-t-butylthiophenyl)-2-cyanoacrylamides in polyphosphoric acid leads to the formation of 3-carboxamido-2-imino-2H-benzo[b][l]thiopyrann intermediates which afford thiocoumarins on hydrolysis. The authors postulate the intermediate formation of a thiophenate ion by an electronic mechanism involving six centers.