Reaction Of Alkyl Halides Research Articles

Halogen effects in electron-transfer reactions of alkyl halides with disodium tetraphenylethylene. Do alkyl halide anion-radicals have finite lifetimes in solution?

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHalogen effects in electron-transfer reactions of alkyl halides with disodium tetraphenylethylene. Do alkyl halide anion-radicals have finite lifetimes in solution?John F. Garst, Rex D. Roberts, and Joseph A. PacificiCite this: J. Am. Chem. Soc. 1977, 99, 10, 3528–3529Publication Date (Print):May 1, 1977Publication History Published online1 May 2002Published inissue 1 May 1977https://doi.org/10.1021/ja00452a070RIGHTS & PERMISSIONSArticle Views66Altmetric-Citations18LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (278 KB) Get e-Alerts Get e-Alerts

The reaction of alkyl halides with the bis(1,2-dicyanoethylenedithiolato)lead(II) ion

The reaction of the bis(1,2-dicyanoethylenedithiolato)lead(II) ion, Pb(mnt) 2− 2, with various organohalides has been examined and found to yield the halo(1,2-dicyanoethylenedithiolato)lead(II) ion Pb(mnt)X − (X = Br, I) and the 1,2-di(alkylmercapto) 1,2-dicyanoethylene, R 2mnt (R = 1°, 2° alkyl). Qualitative rate studies have shown that the alkylation proceeds much faster for Pb(mnt) − 2 than for Na 2mnt.

Reaction of Alkyl Halides with Mercury(II) Salts in Tetrahydrofuran. A Facile Preparation of 4-Alkoxybutyl Acetates and Chlorides

Abstract The reaction of primary and secondary alkyl iodides and bromides with Hg(OAc)2 and HgCl2 in tetrahydrofuran (THF) affords the THF-incorporated compounds (1), RO(CH2)4X [X=OAc and Cl, respectively], in good yields. When HgBr2 and aqueous or alcoholic Hg(ClO4)2 were used as mercury(II) salts, the yields of 1(X=Br, OH, and OR′) were low. Similar treatment with HgI2 gave scarcely any 1. A reaction scheme which involves O-alkyltetrahydrofuranium ion as the intermediate is proposed for the formation of 1.

Recent Results on Chemical Modification of Polymers

Abstract Some characteristic features of chemical transformations of polymers are examined on three examples: 1 The reactions of various organo-lithium bases onto the ester carbonyls of polymethylmethacrylate are typical examples of one-step substitutions involving retardation, i.e. decreased reactivity of units vicinal to substituted ones. 2 The reaction of phenyl-lithium onto the carbonyl groups of PMMA is a typical two-step substitution process, with additional possibilities of cyclization via lactonization or via acetalization. To understand the reactions involved it is necessary to make use of model-molecules and of copolymers where cyclizations are avoided. It was established that retardation characterizes the first step (ketone formation) but the probability of the second step to occur subsequently is rather high. Lactonization (by attack of an alcoolate onto a vicinal ester) is therefore somewhat privileged. 3 Chemical modification of polyvinylalcohol by metallation and subsequent reactions of alkylhalides or of propane sultone was investigated thoroughly. It was found that sequential substitution was obtained. This is due to enhanced reactivity of units vicinal to substituted ones (case or propane sultone); but it may also be due to the tendency of side chains to crystallize in double layers, in which case the placement of the substituted units is determined by physical effects rather than by purely chemical factors.

The Reaction of Alkyl Halides with Mercuric Thiocyanate in Tetrahydrofuran. The Solvent Incorporation and the Intermediacy of O-Alkyltetrahydrofuranram Ions.

Abstract The reaction of alkyl halides with mercuric thiocyanate in tetrahydrofuran (THF) affords mainly the THF-incorporated products, R[O(CH2)4]nNCS and R[O(CH2)4]nSCN (mostly n=1 and 2), where the isomer ratios (N/S ratios) are nearly 1. The reaction of EtO(CH2)mBr (m=2–5) with mercuric thiocyanate in THF or n-Bu2O proceeds rapidly only in the case of m=4 to give EtO(CH2)4NCS and EtO(CH2)4SCN, the N/S ratio being also nearly 1, and gives EtNCS and EtSCN when m=5, while the reaction with potassium thiocyanate in DMF affords a good yield of EtO(CH2)mSCN (m=2–5) as nearly the only product. It is suggested that the titled reaction involves the initial formation of a five-membered oxonium ion, O-alkyltetrahydrofuranium ion, and a subsequent attack by XHg(SCN)2−.

ChemInform Abstract: THE EFFECT OF PRESSURE ON THE RATES OF SOME SUBSTITUTION REACTIONS OF ALKYL HALIDES

Measurements have been made of the influence of hydrostatic pressure on the rates of three kinds of bimolecular substitution reactions of alkyl halides in solution. They are reactions with (a) halide ions in acetone solution (Finkelstein reactions), (b) silver nitrate in aqueous ethanol and (c) mercuric nitrate in aqueous dioxan. The Finkelstein reactions were unsymmetrical with respect to the halogen atoms, for instance I- + PrCl → PrI+Cl-. They were all accelerated by an increase of pressure, in contrast to the sym- metrical exchange I*- + PrI → PrI* + I-, which is known to be retarded by an increase of pressure. This fact supports Gonikberg's view of the role of partial desolvation in the symmetrical reactions. Reactions involving LiCl as the source of halide ions were accelerated much more than those involving KI, simply because an increase of pressure enhances the dissociation of unreactive LiCl ion pairs. Reactions of the types (6) and (c) were also accelerated by an increase of pressure, a fact which argues against a suggestion that the attacking species might be ion pairs.

Photochemical reactions of alkyl halides with coordinated dinitrogen. Formation and structural characterization of novel alkyldiazenido derivatives of molybdenum

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemical reactions of alkyl halides with coordinated dinitrogen. Formation and structural characterization of novel alkyldiazenido derivatives of molybdenumVictor W. Day, T. Adrian George, and S. D. Allen IskeCite this: J. Am. Chem. Soc. 1975, 97, 14, 4127–4128Publication Date (Print):July 1, 1975Publication History Published online1 May 2002Published inissue 1 July 1975https://doi.org/10.1021/ja00847a042RIGHTS & PERMISSIONSArticle Views117Altmetric-Citations39LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (293 KB) Get e-Alerts Get e-Alerts

The use of kinetically generated unstable enolate ions in the regiospecific formation of carbonxarbon bonds. Specific applications to annelation processes

Abstract

The effect of pressure on the rates of some substitution reactions of alkyl halides

Measurements have been made of the influence of hydrostatic pressure on the rates of three kinds of bimolecular substitution reactions of alkyl halides in solution. They are reactions with (a) halide ions in acetone solution (Finkelstein reactions), (b) silver nitrate in aqueous ethanol and (c) mercuric nitrate in aqueous dioxan. ��� The Finkelstein reactions were unsymmetrical with respect to the halogen atoms, for instance I- + PrCl → PrI+Cl-. They were all accelerated by an increase of pressure, in contrast to the sym- metrical exchange I*- + PrI → PrI* + I-, which is known to be retarded by an increase of pressure. This fact supports Gonikberg's view of the role of partial desolvation in the symmetrical reactions. Reactions involving LiCl as the source of halide ions were accelerated much more than those involving KI, simply because an increase of pressure enhances the dissociation of unreactive LiCl ion pairs. ��� Reactions of the types (6) and (c) were also accelerated by an increase of pressure, a fact which argues against a suggestion that the attacking species might be ion pairs.

The Reaction of Alkyl Halides with Mercuric Thiocyanate

Abstract The reaction of secondary and tertiary alkyl halides with mercuric thiocyanate in less-polar solvents e.g., n-hexane, di-n-butyl ether, and 1,2-dichloroethane) was found to afford predominantly N-alkylation products, alkyl isothiocyanates, in contrast to the reaction with potassium salt in DMF. Especially, from t-butyl bromide, α-phenethyl bromide and benzhydryl chloride, the corresponding pure isothiocyanates were obtained in good yields. A most probable reaction mechanism is suggested, based on the relative rate data, the stereochemical result of the reaction with optically active α-phenethyl bromide, and the well-known catalytic effect of silver or mercury salt in SN1 reaction.

Preparation and reactions of alkylcobalt complexes containing schiff base ligands

A series of Co II(sal 2Bg) and RCo(sal 2Bg) complexes have been prepared from the tetradentate H 2(sal 2Bg) diimino ligands formed by the condensation of salicyclaldehyde and various diamines. The RCo(sal 2Bg) complexes (R = methyl, ethyl, n-propyl, and i-propyl) are synthesized by the reactions of alkyl halides with Co I(sal 2Bg) -. The complexes are characterized by UV-visible, IR, and PMR spectra. The cleavage of the cobaltcarbon bond by light, I 2, CN -, HS -, R'S -, and R'SH was studied. The organic products were identified by GLPC, and the cobalt complexes by isolation and analysis. A rich variety of mechanisms is discussed.

Chemistry of Transition Metals. IV. Reactions of Alkyl Halides with the Metals of the First Transition Period

The reactions of 1-chloropropane (1) and 1-chloro-2-methylpropane (2) with clean, polycrystalline films of the metals Ti through Cu were studied at ambient and elevated temperatures. At ambient temperature all of the metals exhibited a complex pattern of behavior. Titanium was uniquely different from other metals in that no catalytic hydrogenation of product olefin by product hydrogen was observed.At elevated temperatures the two reactants exhibited the same dichotomy as previously reported for titanium in that 2 was catalytically dehydrochlorinated by all metals, whilst 1 underwent non-catalytic dehydrochlorination. Except in the cases of Ti and Mn, the halide deposited by reaction of 1 with the metal surfaces provided an effective diffusion barrier to further reaction. It is suggested that the rate-controlling step for both Ti and Mn in reactions with 1 is transport of metal atoms from the pure metal into the halide surface layer.

Reaction of Alkyl Halides and Methanesulfonates with Aqueous Potassium Fluoride in the Presence of Phase-Transfer Catalysts: a Facile Synthesis of Primary and Secondary Alkyl Fluorides

Reaction of Alkyl Halides and Methanesulfonates with Aqueous Potassium Fluoride in the Presence of Phase-Transfer Catalysts: a Facile Synthesis of Primary and Secondary Alkyl Fluorides

ChemInform Abstract: OXIDATIVE ADDITIONS OF ALKYL HALIDES TO PALLADIUM(0) CARBONYL COMPLEX

AbstractDie oxidative Addition der Alkylhalogenide (II) an den Pd(O)‐Komplex (I), die zu den′ trans‐Pd(II)‐Komplexen (III) führt, wird untersucht.

Oxidative Additions of Alkyl Halides to Palladium(0) Carbonyl Complex

Abstract Oxidative addition reactions of alkyl halides to Pd(CO)(PPh3)3 were studied. Vinyl chloride, allyl chloride, allyl bromide, methallyl chloride, benzyl bromide, methyl iodide, and iodobenzene react with Pd(CO)(PPh3)3 to afford the corresponding acyl complexes of the type to the type trans-PdX(COR)(PPh3)2. The reactions proceed rapidly when the dissociation energy of carbon-halogen bond in the saturated alkyl halides is smaller than about 60 kcal/mol. In the case of the unsaturated alkyl halides the more inert carbon-halogen bond can be activated by initial formation of π complexes.

Stereoselectivity of the elimination reactions of alkyl halides over silica gel and alkali-treated silica gel

The stereochemistry ( anti or syn mode) of dehydrohalogenation of 2-bromobutane, 2,3-dichlorobutane and 2,3-dibromobutane over various solid acids and bases, such as silica gel and alkali salt-impregnated silica gels, at 95–300 °C was determined from the products of the diastereomeric isomers of each compound. The steric course of dehydrobromination of 2-bromobutane at low temperatures was mainly anti mode over KOHSiO 2, K 2CO 3SiO 2 and syn mode over SiO 2. At high temperatures, syn elimination was the favored mode over most catalysts studied. The reactions of 2,3-dihalobutanes proceeded by anti elimination over those solid surfaces. From the variation in the stereochemical reactions of the catalysts and reactants, the ease of β-proton elimination, which increases with the acidity of β-proton and basicity of solid, was found to be the prime factor determining the steric course of reaction. The reaction mechanism is discussed on the basis of the stereochemistry, isotope effects and the relative reactivity of various alkyl halides.

Metallation of N-Substituted β-Lactams. A Method for the Introduction of 3-Substituents into β-Lactams

N-Alkyl and N-aryl β-lactams yield lithio carbanions upon reaction with lithium diisopropylamide in tetrahydrofuran at −78°. These lithio salts react with a variety of electrophiles (e.g. ketones, esters, reactive alkyl halides) to give the 3-substituted derivatives in fair to good yield. The procedure is useful for the preparation of rather complex 3-substituted β-lactams from readily available simple derivatives.

A rapid mild esterification method

Abstract The well known method for the formation of carboxylate esters by the reactions of alkyl halides with metal salts of Carboxylates (where M includes Ag, pb, and alkali metals) is not a generally useful synthetic method1. Several improvements have increased the utility of this method2–5.Chief among them is the use of ammonium salts rather than metal salts. Moreover, amines and quaternary ammonium salts in catalytic amouts also increase the rate of the reactions, i.e., at room temparature or below except when highly active alkyl halides are employed.

Stoicheiometry and synthetic utility of the reaction of alkyl halides with lithium dihydronaphthylide

Organolithium reagents (RLi) are formed in the reaction of lithium dihydronaphthylide (Li+C10H8·–) with alkyl halides (RX); the stoicheiometry of the reaction (Li+C10H8·–: RX) varied from 2 : 1 (with the highest yield of RLi) to 1 : 1 (no RLi formed).

New acetyl- and methyl-iron complexes

Several oxidative addition reactions of alkyl halides with derivatives of iron carbonyl have been undertaken at varying degrees of substitution, basicity and bulkiness of phosphine ligands. Only trimethylphosphine leads to a stable trans-iodoacetyl derivative which decarbonylates to give the cis-iodo-methyl derivative of di- carbonylbis(trimethylphosphine)iron. Methyl migration mechanism to the nearest CO during carbonylation reaction has been confirmed. The experimental evidence suggests that the reactivity of trigonal bipyramidal iron complexes depends on the negative charge associated with the remaining carbonyl ligands, and on the bulkiness of the phosphine ligands.