Alkanes aluminum hydrides + alkyl halides

Tetra-p,3-carbonyldodecacarbonylhexa-rhodium, 288 of alkyl halides to alkanes Chromium(II) chloride, 84 Lithium aluminum hydride-Ceri-um(III) chloride, 159... 

Primary and secondary alkyl bromides, iodides, and sulfonates can be reduced to the corresponding alkanes with LiBHEt3 (superhydride) or with lithium aluminum hydride (LiAlH4, other names lithium tetrahydridoaluminate or lithium alanate). If such a reaction occurs at a stereocenter, the reaction proceeds with substantial or often even complete stereoselectivity via backside attack by the hydride transfer reagent. The reduction of alkyl chlorides to alkanes is much easier with superhydride than with LiAlH4. The same is true for sterically hindered halides and sulfonates ... 

It will be recalled that methane (CH4) can be converted to nitromethane (H3CNO2) by the action of nitric acid on methane at high temperature (Chapter 6, Equation 6.10). The nitration of other alkanes by the same process can also be effected, but separation of the multitude of isomers that can be formed (from all but the simplest alkanes) can be difficult. Nitroalkanes, R-NO2 (sometimes accompanied by their corresponding nitrite isomers, R-ONO), can also be prepared (as shown in Chapter 7, Table 7.5e) by treatment of alkyl halides with nitrite anion (ONO ). Reduction of nitroalkanes (R-NO2) with hydrogen (H2) in the presence of a platinum (Pt) catalyst or lithium aluminum hydride (LiAIlT,) in ether produces the corresponding amine (Equation 10.18). 

The acylation of alkanes has also been known for a long time, but for synthetic purposes is limited to simple substrates. The initial step is hydride abstraction by an acylium ion, a process well established in the presence of a powerful Lewis acid, most commonly an aluminum halide, or strong protic acid. The carbocation so formed can then undergo elimination, possibly after hydride or alkyl migration, to give an alkene which is then acylated. In the presence of excess alkane, saturated ketones are formed by a further intermolecular hydride transfer, whereas with an excess of acyl halide, the product is the (conjugated) unsaturated ketone. -" The synthetic potential is obviously likely to be limited to simple substrates. 

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