Hydroxyalkylation de la methylvinylcetone et de l'acrylonitrile en presence de diaza-1,4 bicyclo [2.2.2] octane

Pure methyl vinyl ketone and acrylonitrile react with aldehydes in the presence of 1,4-diazabicyclo[2.2.2] octane (DABCO) to give high yields of α-methylene-β-hydroxyketones and nitriles respectively. Michael addition occurs with methyl vinyl ketone and gives rise to 3-methylene-2,6 heptadione.     

L'acide hydroxylamine-O-sulfonique,réactif de choix pour la conversion d'aldéhydes en nitriles

Hydroxylamine-O-sulfonic acid: a convenient reagent for the conversion of aldehydes into nitriles . Hydroxylamine-O-sulfonic acid (HAS) proved to be an excellent reagent for the conversion of aliphatic, aromatic and heteroatomic aldehydes into nitriles. There, aldehydes in the form of suspension in HAS water solution, react rapidely to give the corresponding nitriles in high yield. Only with formylpyridines could the intermediate oxime-O-sulfonic acids be isolated.     

Alkylations en α de fonctions organiques par l'intermédiaire de compostés organostanniques

Organotin enolates and α-organotin substituted nitriles or esters which are generally easy to obtain, can be used to alkylate α to functional groups.In the case of organotin enolates, heating with alkylating agents, usually gives monoalkylated products in very good yields: numerous examples with ketones and aldehydes are described.With α-organotin substituted nitriles and esters, direct alkylation does not occur, but good results can be obtained in the presence of either magnesium or lithium bromide, or after a metal exchange reaction with a Grignard or lithium reagent.     

Synthese directe de cetones par reaction de reformatsky

The Reformatsky reaction of nitriles, with α-bromo salts

, gives, after neutral hydrolysis, ketones in good yield. Nitriles with particulary mobile α hydrogens, such as benzyl cyanide, react in the same way.The reaction mechanism has been studied.     

Recherches sur la synthese totale des alcaloides appartenant a la serie de la carpaine et de la cassine—II : Une synthese totale de la pseudo–conhydrine de type biogenetique

The synthesis is described of t-6-propyl-3-piperidinol (dl-pseudo-conhydrine) in 3 steps from 4-4-ethylenedioxy heptanal. This reaction is similar to that recently suggested for the biosynthesis of 2-propylpiperidine (coniine).     

Preparation of imidazolines from aziridines and nitriles via TfOH promoted Ritter process

An efficient preparation of imidazolines from nitriles and aziridines in the presence of TfOH via Ritter reaction is described. It indicates that different kinds of nitriles can undergo the process. Among the nitriles, pivalonitrile is proven to be better than acetonitrile. The reaction is performed at room temperature and the yields are excellent.     

C-Silylation de composes a fonction nitrile. Synthese de nitriles α-silicies

The direct silylation by Me₃SiCl/Li/THF of saturated nitriles having a hydrogen atom in the α position with respect to the function leads, according to a simple and rapid process, to the corresponding α-silylated nitriles in yields that are moderate but much higher than those given by the comparable previously known routes. α, β-Unsaturated nitriles give the derivatives resulting from the disilylation of the double bond. Allyl or benzyl cyanide and diphenyl acetonitrile first undergo the elimination of the nitrile group (which behaves as a halogen atom) whereas cyanamid affords bis(trimethylsilyl)carbodiimide giving after further silylation the unexpected tris(trimethylsilyl)amine.     

Modelisation de la dynamique de fermentation alcoolique

The control of the alcoholic fermentation is necessary to obtain a wine having good organoleptic properties. Our study consists in applying the overall dynamical and phenomenological modelling to this kind of reaction suggesting however hypothesis concerning kinetic laws (order zero and order one). The first proposed models are not perfect but they allowed us to access certain chemical parameters such as the reaction enthalpy. Our aim is to determine a model of simple state (for its application) to allow the conception of the alcoholic fermentation reaction of a real-time command.     

Direct oxidative conversion of alkyl halides into nitriles with molecular iodine and 1,3-diiodo-5,5-dimethylhydantoin in aq ammonia

Various benzylic halides were smoothly and directly converted into the corresponding aromatic nitriles in high yields using molecular iodine and 1,3-diiodo-5,5-dimethylhydantoin, respectively, in aq ammonia. Similarly, primary alkyl halides were also converted into corresponding nitriles in moderate to good yields using molecular iodine and 1,3-diiodo-5,5-dimethylhydantoin in aq ammonia, although a long reaction time was required. The present reaction is a new method for the preparation of aromatic nitriles from benzylic halides and a new method for the conversion of alkyl halides into corresponding nitriles with retention of the number of carbon atoms.     

Acid Catalyzed Multicomponent Reaction to Access Functionalized N-Benzhydryl Amides: A Tandem Ritter Reaction

Acid catalyzed multicomponent reaction (MCR) for the synthesis of N-benzhydryl amide derivatives from aldehydes, N,N-disubstituted arylamines and nitriles is reported. The reaction is compatible with electronically differentiating aryl/heteroaryl aldehydes/acetals, different nucleophiles (cyclic and acyclic N,N-disubstituted arylamines,β-naphthols, 1,3 dicarbonyl, 1,3,5-trimethoxy benzene), alkyl nitriles, aryl/heteroaryl nitriles in catalytic TFA/TfOH through tandem Ritter reaction. The one-pot MCR with broad substrate scope generated a wide variety of sterically hindered N-substituted amides and is successfully applied for the synthesis of isoindolinone.     

Fonctionnalisation de polymeres insatures—action du chloracetonitrile en milieu basique sur les organoboranes derives des polyalcadienes

Trialkylboranes react with chloroacetonitrile in the presence of potassium 2.6-di-tert-butylphenoxide to give nitriles. This reaction, coupled with hydroboration by 9-bora-bicyclononane, allows selective cyanomethylation of alkenes. The application of this reaction to trialkylborane structures derived from alkene structures of polyisoprenes and polybutadienes has been considered. In order to determine the polydienic structures best suited for this reaction, we have studied model molecules of 1.4 and 1.2 polybutadienes and of 1.4 and 3.4 polyisoprenes and then applied the process to the corresponding polymers.     

Siliciumorganische verbindungen : LIX. 1,5-Bis(trimethylsilyl)-naphthalin

The addition vs. deprotonation ratio in the reaction of nitriles with n-PrMgBr is increased by complexation of the Grignard reagent with LiClO₄. For nitriles having moderately labile α-hydrogen atoms the deprotonation reaction is almost completely suppressed; but for nitriles having very labile α-hydrogen atoms (CH₃ CN, PhCH₂CN) yields in ketones are increased from 2 to 10–20%.     

Preparation of 5-substituted 1H-tetrazoles from nitriles in water.

The addition of sodium azide to nitriles to give 1H-tetrazoles is shown to proceed readily in water with zinc salts as catalysts. The scope of the reaction is quite broad; a variety of aromatic nitriles, activated and unactivated alkyl nitriles, substituted vinyl nitriles, thiocyanates, and cyanamides have all been shown to be viable substrates for this reaction.     

Formation of Four Different Aromatic Scaffolds from Nitriles through Tandem Divergent Catalysis

A zinc bromide complex, formed by the sequential reaction of nitriles with a Reformatsky reagent and terminal alkynes, is used as an intermediate for divergent palladium‐catalyzed reactions. The reaction pathway of the intermediate is precisely controlled by the choice of the reaction solvent or the palladium catalyst to quickly form four different aromatic scaffolds—arylamines, aminoindenes, pyrroles, and quinolines—starting from readily available nitriles.     

Application of the Schmidt reaction for the preparation of tetrazoles (review)

The application of the Schmidt reaction with ketones and nitriles for the preparation of tetrazoles is examined. Modern concepts regarding the mechanism of the reaction of ketones and nitriles with hydrazoic acids are discussed. The range of application of the reaction is indicated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 723–735, June, 1975.     

Novel domino cyclization of tryptophan-derived amino nitriles: scope and stereoselectivity

[reaction: see text] The scope and stereoselectivity of the acid-promoted cyclization of new tryptophan-based alpha-amino nitriles derived from either ketones or aldehydes to novel hexahydropyrrolo[1',2',3':1,9a,9]imidazo[1,2-a]indoles is described. This cyclization involves the generation of two or three stereogenic centers. The time and stereoselectivity of this reaction mostly depended on both the steric volume of the substituents at the amino nitrile and its stereochemistry. Unhindered amino nitriles gave exclusively 2-exo-isomers, while hindered amino nitriles, which required higher reaction times, provided also these isomers under kinetic control. Under thermodynamic control, the 2-endo-isomer was the main reaction product, except for the benzaldehyde-derived alpha-amino nitriles, where a favorable electronic interaction between the phenyl and methoxycarbonyl groups in a relative cis-disposition might be responsible of the formation of the 2-exo-isomer as the only cyclization product.     

From azides to nitriles. A novel fast transformation made possible by BrF3

[reaction: see text]. Various alkyl and aryl azides, readily obtained from halides or alcohols, were transformed into the corresponding nitriles using bromine trifluoride in moderate to good yields. The reaction is general and gives positive results with aliphatic, aromatic, cyclic, and functionalized azides. It can also be applied to the synthesis of optically active nitriles.     

Sur une voie alternative de synthese de la loganine

An original synthesis of a precursor of loganin is described starting from the bicyclo[3.3.O]octane-3,7-dione using Shapiro's reaction. The structures of the obtained derivatives are established on the basis of ¹H N.M.R., I.R.,and mass spectral data.     

Base-Catalyzed Reaction of Cyanoalkylphosphonates with Methanol

The equilibrium conversion of nitriles in the reaction of cyanoalkylphosphonates with methanol in the presence of sodium methylate, as determined by potentiometric titration with perchloric acid in nitromethane, varies from 58 to 17.7%. The practical yields of imidates were evaluated by a preparative procedure of isolation of purified imidates from the reaction mixtures (56-14%). Because of the low conversions of nitriles, the reaction is expedient to use only for preparing alkyl (dialkoxyphosphoryl)acetimidates.     

Etude de la chloration du PVC en masse—II. Influence et evolution de la stereoregularite de la chaine en rapport avec les mecanismes de reaction

Bulk chlorination of PVC has been studied by i.r. and NMR. The evolution of chain stereoregularity during reaction and its significance to reaction mechanism have been specified. In particular, for temperatures <80°, the ratio Cl/C cannot exceed 0.75 because changes of conformation are impossible. To exceed this ratio, additional energy is necessary but then there is a parallel loss of hydrogen chloride. In all cases isotactic diads of TG conformation would be first chlorinated. At temperature above 100°, the microstructure of bulk chlorinated products is similar to that of products prepared in solution while their configuration and conformation are different.