Alkanes tertiary, nitro

Tertiary nitro alkanes or activated nitro groups are reduced to the alkane with loss of the nitro group by a combination of PhSiH3 and catalytic amounts of Oz-BubSnH and l,T-azobis(cyclohexanecarbonitrile) (ACHN), even in the presence of other potentially reducible functional groups.555 The examples shown in Eqs. 331 and 332 illustrate this behavior.555... 

Some unusual benzylic functional groups can be reduced to hydrocarbons using NaBH4 alone in alcohols (equation 54). Choice of solvent can be used to enhance (or reduce) the reductive power of NaBIL. Thus in DMSO (or sulfolane), NaBH4 effectively reduces primary, secondary and tertiary benzylic halides to alkanes, leaving nitro, ester and carboxylic acids untouched (equation 55). There... 

Reduction of Nitro-Substituted Tertiary Alkanes," Weis, C.D. Newkome. Q Synth 1995, 1053... 

Tertiary nitroso compounds are stable and are generally reduced similarly to the corresponding nitro compound, but somewhat more easily. The reduction of mono-and dihalogenated nitrosoalkanes also goes analogously to that of the corresponding nitro-alkanes thus 2-chloro-2-nitrosopropane [42] gives acetoxime on reduction (pH3, E — 0.5V) in 98% yield ... 

The ease of protolysis of tertiary (and to a lesser degree secondary) aliphatic nitro compounds explains in part the complex reaction mixtures obtained in mixed acid nitrations of alkanes. 

Mixture of nitric and sulfuric acid (mixed acid) used extensively in nitration of aromatic hydrocarbons, is generally unsuitable for nitration of alkanes, since primary nitroalkanes are rapidly hydrolyzed by hot sulfuric acid and secondary and tertiary nitroalkanes form tars (in all probability via rapid alkene-forming elimination and subsequent polycondensation, polymerization, etc.). It is, however, significant to point out that it is not necessarily the lack of reactivity of paraffins with mixed acid that makes the nitration of saturated hydrocarbons unsuitable, but that fast secondary reactions of any nitro products formed (as well as oxidative side reactions) can take place. This difficulty can be, at least in part, overcome by using preformed nitronium salts as nitrating agents. 

The radical chain reduction of thioformates, which are generated from tertiary alcohols, with tri-n-butyltin hydride has been reported by Barton and co-workers, and the mildness of tri-n-butyltin hydride as a reducing agent has been nicely demonstrated by the conversion of the bromo-endoperoxide (1) into the endoperoxide (2). The known reduction of nitro-compounds to alkanes. 

Benzylic, secondary, and tertiary alcohols can be reduced to the corresponding alkanes in the presence of esters, halogens, nitro groups, or even primary alcohols via an indium trichloride catalyzed reduction using chlorodiphenylsilane as the hydride source (Eq. 6.72) [117],... 

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