Arylalkyl halides

In the 19.S0 s a number of workers, including Hoshino, Oddo, and Kubota suggested that indolenine-type intermediates (cf. 431) were formed during the reaction of the indole Grignard reagents [depicted as N—MgX derivatives (cf. 432)] with alkyl and arylalkyl halides. Rather surprisingly these were the last reports dealing with... 

These compds are also formed during the prepn of nitriles, by heating aryl or arylalkyl halides, or alkyl sulfuric or phosphoric esters, or arylsulfonic esters with K or Na cyanide in ale... 

The water-soluble calix[n]arenes 6.3 (n = 4, 6 and 8) containing trimethylammonium groups act as efficient inverse phase-transfer catalysts in the nucleophilic substitution reaction of alkyl and arylalkyl halides with nucleophiles in water (Eq. 6.19).40 In the presence of various surfactants (cationic, zwitterionic and anionic), the reactions of different halides and ketones show that the amount of ketone alkylation is much higher and that the reactions are faster in the presence than in the absence of surfactant aggregates.41 The hydrolysis of the halide is minimized in the presence of cationic or zwitterionic surfactants. 

The reduction of arylalkyl halides of the triphenylmethyl type by electro-chemically generated outer sphere single electron donors offers an example of a sequencing of the bond-breaking and electron-transfer steps different from what has been described before. The cleavage of the halide ion then precedes electron transfer which thus involves the carbocation, a mechanism reminiscent of 8, 1 reactions (Andrieux et ai, 1984b) as shown in (102). The... 

Cupric chloride, if present in concentrations above ca. 0.5 M, may cause side reactions to occur in the olefin aiylation reaction similar to those that occur with cupric chloride in the vinyl acetate synthesis mentioned above. The side reaction produces 2-arylethyl chlorides and these products may be made the major ones if cupric chloride is present to the extent of about 2M in 10% aqueous acetic acid solution 29>. The mixed solvent is required to obtain the necessary solubility of the cupric chloride. This is a general reaction useful for producing a variety of 2-arylalkyl halides. For example, 3-phenyl-2-chloropropionaldehyde is obtained in 63% yield by the reaction of phenylpalladium chloride , cupric chloride and acrolein. 

Cellulose Ethers. Cellulose ethers are formed when cellulose, in the presence of alkali or as alkali cellulose, is treated with alkyl or arylalkyl halides. Two types of reaction are employed in the preparation of cellulose ethers. The most common is nucleophilic substitution. Methylation of alkali cellulose with a methyl halide is an example of this type. The other type of etherification reaction is Michael addition. This reaction proceeds by way of an alkali-catalyzed addition of an activated vinyl group to the cellulose. The reaction of acrylonitrile with alkali cellulose is a typical example. The general reaction is outlined in Scheme 4. 

Many aliphatic and arylalkyl halides (Cl, Br, I), sulfates (OSOj"), sulfonates (OSO R), nitrates (NO ), and organo-... 

Tetracarbonylcobaltate anion, generated under PTC conditions, catalyzes the reaction of aryl halides with excess methyl iodide under a CO atmosphere [122]. The reaction produces aryl methyl ketones and carboxylic acids as the main products. Stoichiometric or catalytic iron pentacarbonyl can also be used for the carbonylation of organohalides under PTC conditions [123-128]. For example, reactions of alkyl and arylalkyl halides with CO in aqueous-organic systems using catalytic amounts of Fe(CO)5 and a PT agent afford alkyl- and arylacetic acids as the main products [127]. 

Olah, G. A., Gupta, B. G. B., Narang, S. C. Synthetic methods and reactions 66. Nitrosonium ion induced preparation of amides from alkyl (arylalkyl) halides with nitriles, a mild and selective Ritter-type reaction. Synthesis 274-276. 

Arylalkyl halides undergo cycloalkylation reactions in the presence of a variety of Lewis acids. Depending upon the nature of the Lewis acid, varying amounts of cycloalkylated and other products can be obtained. Equations (94) to (96) show some cycloalkylation reactions of arylhaloalkanes. ... 

Alkylpyrido[2,3-d]pyridazin-5(6//)-one and 5-alkylpyrido[2,3-t/]pyridazin-8(7//)-one, converted into their anions by potassium ferf-butoxide or sodium hydride in dimethylfor-mamide, are, V-alkylated at position 6 or 7 respectively by alkyl or arylalkyl halides, 9 90 e.g. formation of 8 or 9.90... 

Of arylalkyl halides the bromide152,345 reacts more readily than the chloride with sodium sulfite for benzyl chloride addition of sodium hydroxide solution has proved useful. 

Shimizu. S. Kito, K. Sasaki. Y. Hirai. C. Water-soluble calixarenes as new inverse phase-transfer catalysts. Nucleophilic substitution of alkyl and arylalkyl halides in aqueous media. Chem. Conimun. 1997, 1629—1630. 

The halogen derivatives of aromatic hydrocarbons are divided into two classes namely, (a) aryl halides and (b) arylalkyl halides or aralkyl halides. 

Such compoimds are produced by alkylating phenol or its mono- or dialkyl derivatives with various allgrlatii agents. Alkyl halides [82-87, 116] or arylalkyl halides [89, 90], alcohols [85, 91-105, 116], aliphatic [87, 90, 95, 104, 106-127], aromatic [88, 90, 127-135], or cyclic [136-138] olefins are used as such alkylatii agents. 

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