Alkyl halides with alkali metals

Alternatively, esterification of carboxylic acid can be carried out in aqueous media by reacting carboxylic acid salts with alkyl halides through nucleophilic substitutions (Eq. 9.10).20 The reaction rate of alkyl halides with alkali metal salts of carboxylic acids to give esters increases with the increasing concentration of catalyst, halide, and solvent polarity and is reduced by water. Various thymyl ethers and esters can be synthesized by the reactions of thymol with alkyl halides and acid chlorides, respectively, in aqueous medium under microwave irradiation (Eq. 9.11).21 Such an esterification reaction of poly(methacrylic acid) can be performed readily with alkyl halides using DBU in aqueous solutions, although the rate of the reaction decreases with increasing water content.22... 

The synthesis of aliphatic nitro compounds from the reaction of alkyl halides with alkali metal nitrites was discovered by Kornblum and co-workers and is known as the modified Victor Meyer reaction or the Kornblum modification. The choice of solvent in these reactions is crucial when sodium nitrite is used as the nitrite soiuce. Both alkyl halide and nitrite anion must be in solution to react, and the higher the concentration of nitrite anion, the faster the reaction. For this reason, both DMF and DMSO are widely used as solvents, with both able to dissolve appreciable amounts of sodium nitrite. Although sodium nitrite is more soluble in DMSO than DMF the former can react with some halide substrates.Urea is occasionally added to DMF solutions of sodium nitrite to increase the solubility of this salt and hence increase reaction rates. Other alkali metal nitrites can be used in these reactions, like lithium nitrite,which is more soluble in DMF than sodium nitrite but is also less widely available. 

One common present day preparation of dialkyl mono-and ditellurides involves the reaction of alkyl halides with alkali metal tellurides that have been prepared in situ. The reactions are commonly carried out in aqueous or nonaqueous solutions. Solutions of sodimn in liquid ammonia also provide a useful media for the reduction of tellurium. ... 

Wurtz-Fittig reactions are C-C coupling reactions of alkyl halides with alkali metals. This synthetic procedure is often applied for Si-Si coupling of silicon halides. See (a) A. Wurtz, Ann. Chim. Phys. 44, 275 (1855). (b) B. Tollens, R. 

Treatment of alkyl halides with alkali metal or silver cyanate is of no preparative value for the synthesis of cyanates. - - As cyanate ions do represent ambident nucleophiles. Holm and Wentrap tried to reach cyanates under well-defined SnI conditions (Scheme 28). But even treatment of isopropyl iodide with silver cyanate in nitromethane provided only a very low yield of a 1 1 mixture of isopropyl cyanate and the corresponding isocyanate, and from a reaction of silver cyanate with triphenylchloro-methane they isolated only triphenylmethyl isocyanate, although the cyanate may have been an intermediate in this transformation." ... 

Dithiophosphato metal complexes are usually prepared by metathesis of metal halides with alkali metal or ammonium salts. A convenient method uses the redox reaction of his th iophosphory 1 )d is ulfanes (RO)2(S)PSSP(S)(OR)2, with metal species in low oxidation states resulting in the insertion of the metal into the sulfur-sulfur bond.24 Recently it was used for the synthesis of long alkyl chain, liquid platinum(II) dithiophosphates25 and for the synthesis of Ru (CO)2[S2P(OPr%]2 from Ru3(CO)i2 with (Pr 0)2(S)PSSP(S)(0Pr,)2.26... 

Lanthanide alkyl compounds are important alkyl transfer reagents and initiate a variety of catalytic reactions. The transformation of lanthanide alkoxide bonds to lanthanide alkyl bonds seems to be an attractive alternative to the alkylation of lanthanide halides with alkali metal alkyl compounds. For example, the ary-loxide route affords homoleptic lanthanide alkyls in good yield [Eq. (22)] [135]. 

Ziegler and co-workers (12) first reported in 1960 that aluminum alkyls react with alkali metal halides to form either 1 1 or 2 1 complexes... 

Pyrroles do not react with alkyl halides in a simple fashion polyalkylated products are obtained from reaction with methyl iodide at elevated temperatures and also from the more reactive allyl and benzyl halides under milder conditions in the presence of weak bases. Alkylation of pyrrole Grignard reagents gives mainly 2-alkylated pyrroles whereas N-alkylated pyrroles are obtained by alkylation of pyrrole alkali-metal salts in ionizing solvents. 

Alcohols undergo many reactions and can be converted into many other functional groups. They can be dehydrated to give alkenes by treatment with POCI3 and can be transformed into alkyl halides by treatment with PBr3 or SOCU- Furthermore, alcohols are weakly acidic (p/C, — 16-18) and react with strong bases and with alkali metals to form alkoxide anions, which are used frequently in organic synthesis. 

Diesters of phosphorous acid are in general neutral because the phosphorous acid exists mostly in the phosphonate form with one hydrogen directly attached to the phosphorus. But with alkali metals the H can be changed against the alkali and reactive intermediates formed. Such alkali metal derivatives of dialkyl phosphites react with alkyl halides to give dialkyl alkanephosphonates, according to Eqs. (45) and (46). 

Germyl, Stannyl, and Plumbyl Anions The preparative methods for the synthesis of the germyl, stannyl, and plumbyl anions are essentially the same as those mentioned above for the silyl anions. The most widely used methods are (1) reduction of halides R3EX (R = alkyl, aryl E = Ge, Sn, Pb X = Cl, Br) with alkali metals and (2) reductive cleavage of the E-E bond of R3E-ER3 (R = alkyl, aryl E = Ge, Sn, Pb) with alkali metals or organolithium reagents. Due to the favorable polarization of the (E = Ge, Sn, Pb) bond, the direct metalation... 

Reactions at o -Position. Many studies have been concerned with the reactions of alkyl halides with cyanide in the presence of various metal ions, and with the direct alkylation of cyanide complexes. The classic synthesis of isonitriles was accomplished by the use of silver cyanide, whereas the corresponding reaction of organic halogen compounds with alkali cyanides yields nitriles (Equations 40 and 41) (34,36). 

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