Halides hydrocarbons, synthesi

Synthesis of pure enantiomers. Brown and Singaram1 have reviewed the chiral organoboranes obtained from (+)- and (- )-pinene and their use for synthesis of optically pure amines, halides, hydrocarbons, lithium alkylborohydrides, ketones, aldehydes, a-chiral acids, esters, nitriles, alkynes, and alkenes. 

Keduction of alkyl halides. Alkyl halides are reduced readily to hydrocarbons by organosilanes under catalysis with aluminum chloride. This hydrocarbon synthesis is limited to alkyl halides that are not rearranged by the catalyst. Primary, secondary, and tertiary halides are reduced. Reduction with triethyl-... 

Wuftz synthesis Alkyl halides react with sodium in dry ethereal solution to give hydrocarbons. If equimolecular amounts of two different halides are used, then a mixture of three hydrocarbons of the types R — R, R — R and R —R, where R and R represent the original radicals, will be formed. The yields are often poor owing to subsidiary reactions taking place. 

Anisole and mixtures of diethyl ether with aromatic hydrocarbons have both been widely employed as solvents for these reactions. Ethers other than diethyl ether and anisole have also been successfully used (cf. refs. 14-17). Hcxamethylphosphorotriamide has recently been used as a solvent for indole Grignard reactions. Young and Mizianty have recently described the use of an aromatic magnesium halide (phenylmagnesium bromide) for the synthesis of indole magnesium bromide. 

This reaction can be used for the synthesis of hydrocarbons but it may also take place as a side-reaction during generation of a Grignard reagent from an alkyl halide and magnesium, then leading to formation of undesired side-products. 

An alkyne is a hydrocarbon that contains a carbon-carbon triple bond. Alkyne carbon atoms are sp-hybridized, and the triple bond consists of one sp-sp a bond and two p-p tt bonds. There are relatively few general methods of alkyne synthesis. Two good ones are the alkylation of an acetylide anion with a primary-alkyl halide and the twofold elimination of HX from a vicinal dihalide. 

A highly versatile method for the synthesis of alkanes and other hydrocarbons from organic halides has been developed by E. J. Corey (Harvard University, Nobel Prize for Chemistry in 1990), G. H. Posner (The Johns Hopkins University), and by G. M. Whitesides (Harvard University) and H. O. House (Georgia Institute of Technology). 

Fittig s synthesis org chem The synthesis of aromatic hydrocarbons by the condensation of aryl halides with alkyl halides, using sodium as a catalyst. fid-iks, sin-tho-s3s ... 

Stilbenes, photocyclization of, 30, 1 StiUe reaction, 50, 1 Stobbe condensation, 6, 1 Substitution reactions using organocopper reagents, 22, 2 41, 2 Sugars, synthesis by glycosylation with sulfoxides and sulfinates, 64, 2 Sulfide reduction of nitroarenes, 20, 4 Sulfonation of aromatic hydrocarbons and aryl halides, 3, 4 Swem oxidation, 39, 3 53, 1... 

Phenols resemble aryl halides in that the functional group resists displacement. Unlike ROH, phenols do not react with HX, SOCI2, or phosphorus halides. Phenols are reduced to hydrocarbons, but the reaction is used for structure proof and not for synthesis. 

Organometallics are generally strong nucleophiles and bases. They react with weak acids, e.g. water, alcohol, carboxylic acid and amine, to become protonated and yield hydrocarbons. Thus, small amounts of water or moisture can destroy organometallic compounds. For example, ethylmag-nesium bromide or ethyllithium reacts with water to form ethane. This is a convenient way to reduce an alkyl halide to an alkane via Grignard and organolithium synthesis. 

The only formic acid derivative that allows the direct formylation of aromatics is formyl fluoride1617 since others (halides and the anhydride) that could be used in Friedel-Crafts-type acylations are quite unstable. Other related methods, however, are available to transform aromatic hydrocarbons to the corresponding aldehydes. The most frequently used such formylations are the Gattermann-Koch reaction16 17 and the Gattermann synthesis.10 16 17... 

The single-monomer route (eq. 5) is preferred as it proves to give more linear and para-linked repeat unit structures than the two-monomer route. Other sulfone-based polymers can be similarly produced from sulfonyl halides with aromatic hydrocarbons. The key step in these polymerizations is the formation of the carbon—sulfur bond. High polymers are achievable via this synthesis route although the resulting polymers are not always completely linear. 

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