Chlorides, alkyl, also

Polymerization occurs at active sites formed by interaction of the metal alkyl with metal chloride on the surface of the metal chloride crystals. Monomer is chemisorbed at the site, thus accounting for its orientation when added to the chain, and propagation occurs by insertion of the chemisorbed monomer into the metal—chain bond at the active site. The chain thus grows out from the surface (31). Hydrogen is used as a chain-transfer agent. Chain transfer with the metal alkyl also occurs. 

Refluxing linoleic acid and a primary or secondary alkyl amine with -toluenesulfonic acid in toluene for 8—18 h also yields the substituted amides (32—34). The reaction of methyl esters with primary or secondary amines to make substituted amides is catalyzed with sodium methoxide. Reactions are rapid at 30°C under anhydrous conditions (35). Acid chlorides can also be used. Ai,A/-dibutyloleamide [5831-80-17 has been prepared from oleoyl chloride and dibutyl amine (36). 

Stannic chloride is also used widely as a catalyst in Eriedel-Crafts acylation, alkylation and cycHzation reactions, esterifications, halogenations, and curing and other polymerization reactions. Minor uses are as a stabilizer for colors in soap (19), as a mordant in the dyeing of silks, in the manufacture of blueprint and other sensitized paper, and as an antistatic agent for synthetic fibers (see Dyes, application and evaluation Antistatic agents). 

Another route to enantiomcrically pure iron-acyl complexes depends on a resolution of diastereomeric substituted iron-alkyl complexes16,17. Reaction of enantiomerically pure chloromethyl menthyl ether (6) with the anion of 5 provides the menthyloxymethyl complex 7. Photolysis of 7 in the presence of triphenylphosphane induces migratory insertion of carbon monoxide to provide a racemic mixture of the diastereomeric phosphane-substituted menthyloxymethyl complexes (-)-(/ )-8 and ( + )-( )-8 which are resolved by fractional crystallization. Treatment of either diastereomer (—)-(/J)-8 or ( I )-(.V)-8 with gaseous hydrogen chloride (see also Houben-Weyl, Vol 13/9a, p437) affords the enantiomeric chloromethyl complexes (-)-(R)-9 or (+ )-(S)-9 without epimerization of the iron center. 

Schrauzer and co-workers have studied the kinetics of alkylation of Co(I) complexes by organic halides (RX) and have examined the effect of changing R, X, the equatorial, and axial ligands 148, 147). Some of their rate constants are given in Table II. They show that the rates vary with X in the order Cl < Br < I and with R in the order methyl > other primary alkyls > secondary alkyls. Moreover, the rate can be enhanced by substituents such as Ph, CN, and OMe. tert-Butyl chloride will also react slowly with [Co (DMG)2py] to give isobutylene and the Co(II) complex, presumably via the intermediate formation of the unstable (ert-butyl complex. In the case of Co(I) cobalamin, the Co(II) complex is formed in the reaction with isopropyl iodide as well as tert-butyl chloride. Solvent has only a slight effect on the rate, e.g., the rate of reaction of Co(I) cobalamin... 

Good yields of chlorides have also been obtained for reaction of isolated diazonium tetrafluoroborates with FeCl2-FeCl3 mixtures.100 It is also possible to convert anilines to aryl halides by generating the diazonium ion in situ. Reaction of anilines with alkyl nitrites and Cu(II) halides in acetonitrile gives good yields of aryl chlorides and bromides.101... 

Carbene complexes have also been prepared by transmetallation reactions. Lithiated azoles react with gold chloride compounds and after protonation or alkylation the corresponding dihydro-azol-ylidene compounds, e.g., (381) or (382), are obtained.22 9-2264 Silver salts of benz-imidazol have also been used to obtain carbene derivatives.2265 Mononuclear gold(I) carbene complexes also form when trimeric gold(I) imidazolyl reacts with ethyl chlorocarbonate or ethyl idodate.2266,2267 The treatment of gold halide complexes with 2-lithiated pyridine followed by protonation or alkylation also yields carbene complexes such as (383).2268 Some of these carbene complexes show luminescent properties.2269-2271... 

They offer the advantage that reductions can be effected under conditions that permit the conversion of substrates that may be adversely sensitive to the presence of strong Brpnsted acids. For example, in the presence of a 10% excess of triethylsilane, addition of one-half equivalent of boron trifluoride etherate to octanal results, within one hour, in the formation of a 66% yield of dioctyl ether after a basic hydrolytic workup. Benzaldehyde provides a 75% yield of dibenzyl ether under the same reaction conditions. The remainder of the mass is found as the respective alcohol.70 Zinc chloride is also capable of catalyzing this reaction. With its use, simple alkyl aldehydes are converted into the symmetrical ethers in about 50% yields.330... 

The synthesis of analogous iminoacyl complexes by isonitrile insertion into linear alkyl-zirconocene chlorides is also known. In an overall regiospecific hydrocyanation of alkenes, iminoacyls 21 derived from tBuNC or Me3SiCN (as the Me3SiNC isomer) may be treated with I2 to rapidly generate an imidoyl iodide and subsequently the nitrile 22 (Scheme 3.6) [22], Less hindered iminoacyl complexes (e. g. R = Bu, Cy) may be hydrolyzed to afford aldehydes 23 [23]. 

In (—)-ion mode besides the [M — H] the chloride adduct also appeared in the MS spectra with a similar intensity, but optimisation of the ESI interface parameters allowed the formation to significantly shift towards the [M — H] ion, while the chloride adduct was largely suppressed. The molecular ion yielded two fragments, one including the alkyl chain [CH3-N-CO-R]-, the other the sugar part [Gluc-N-CH3]. ... 

Azetidones (p-lactams) are generally obtained in high yield from (3-halopropion-amides (Table 5.18) and the low yield from the reaction of N-phenyl (3-chloropropi-onamide can be reconciled with the isolation of A-phenyl acrylamide in 58% yield [34]. The unwanted elimination reaction can be obviated by conducting the cyclization in a soliddiquid system under high dilution [35, 36]. Azetidones are also formed by a predominant intramolecular cyclization of intermolecular dimerization to yield piperazine-2,5-diones, or intramolecular alkylation to yield aziridones. Aone-pot formation of azetidones in 45-58% yield from the amine and P-bromocarboxylic acid chloride has also been reported [38]. 

Procedures for synthesis of ketones based on coupling of organostannanes with acyl chlorides have also been developed.152 153 The catalytic cycle is similar to that involved in the coupling with alkyl or aryl halides. The scope of compounds to which the procedure can be applied is wide and includes successful results with tetra-n-buty lstannanc. This example implies that the reductive elimination step in the mechanism can compete successfully with -elimination. 

Phosphorus pentachloride is used as a chlorinating agent in many organic syntheses, such as production of alkyl and acid chlorides. It also is a catalyst in manufacturing acetylcellulose. 

Mg+" reacts with alkyl halides in the gas phase via a range of substrate-dependent pathways Not all halides are reactive—examples of unreactive substrates include methyl chloride, vinyl chloride, trichloro and tetrachloro ethylene. Reaction with ethyl chloride proceeds via an elimination reaction (equation 18) followed by a displacement reaction (equation 19). For larger alkyl halides, such as isopropyl chloride, chloride abstraction also occurs (equation 20). For multiply halogenated substrates such as carbon tetrachloride, oxidative reactions occur (equations 21 and 22), although organometallic... 

Alkyl halides are almost always prepared from corresponding alcohols by the use of hydrogen halides (HX) or phosphorus halides (PX3) in ether (see Section 5.5.3). Alkyl chlorides are also obtained by the reaction of alcohols with thionyl chloride (SOCI2) in triethylamine (Et3N) or pyridine (see Section 5.5.3). 

Symmetrical ethers are obtained from the dehydration of two molecules of alcohol with H2SO4 (see Section 5.5.3). Alcohols react with p-toluenesul-phonyl chloride (tosyl chloride, TsCl), also commonly known as sulphonyl chloride, in pyridine or EtsN to yield alkyl tosylates (see Section 5.5.3). Carboxylic acids, aldehydes and ketones are prepared by the oxidation of 1° and 2° alcohols (see Sections 5.7.9 and 5.7.10). Tertiary alcohols cannot undergo oxidation, because they have no hydrogen atoms attached to the oxygen bearing carbon atom. 

There is also an enzyme for removal of methyl and ethyl groups from bases by oxidizing them to their respective aldehydes-the Aik B repair enzyme. Lipid epoxides, which may be produced in inflammatory tissue and can yield alkylated bases, will also be repaired by this enzyme (Fig. 6.47). Metabolic activation of vinyl chloride will also yield the same adduct (see chap. 7). 

Zinc chloride is much less reactive than aluminum chloride and usually requires higher reaction temperatures. However, it has the advantage that, unlike aluminum chloride, it is less sensitive to moisture and can sometimes even be used in aqueous media.88 Concentrated aqueous solutions of ferric chloride, bismuth chloride, zinc bromide, stannous chloride, stannic chloride, and antimony chloride are also alkylation catalysts, particularly in the presence of hydrochloric acid.89... 

Scheme 1) whereas the reaction with the D-man/io-hexodialdo-l,5-pyranose derivative 3 produced, in low yield, the cyanohydrin 4 having an L-glycero-D-manno configuration and the stereoisomeric epimer at C-5, rather than at C-6 [14J. With an atm toward the synthesis of d- and L-glycero-D-manno-heptoses, the reaction of 3 with other reagents (2-inethyl-furan, alkyl magnesium chlorides) was also explored, without any substantial improvement of either stereoselectivity or yield. 

It should be noted that owing to the great affinity of the phenol for sodium, no sodium alcoholate remains to react with the ethyl iodide. Diethyl ether, however, may be prepared in a similar manner, using the same quantities of sodium, alcohol and ethyl iodide as above. The ether and excess of alcohol are distilled off and the ether separated from the alcohol by the addition of salt solution. Anisole (phenylmethyl ether, B.P. 154°, see p. 218) can also be prepared in a similar way, using corresponding quantities of methyl alcohol and methyl iodide. The alkyl iodides give the best yields, but alkyl chlorides can also be employed. 

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