Reduction of Miscellaneous Nitrogen-Containing Compounds

The combination of PhSiH3 with a catalytic amount of bis(tri-n-butyltin) oxide reduces azides to primary amines in excellent yields (Eq. 3 33).556 The reducing agent is (n-Bu)3SnH formed in situ by the silane. Azides are converted into Boc-protected primary amines with the PMHS/Pd/C reagent (Eq. 3 34).557,558 

The combination of Et3SiH/Co2(CO)8 reduces nitriles to the A,A-bis(trime-thylsilyl)amine (Eq. 335).559 These derivatives can be readily hydrolyzed to the primary amines. 

The organosilane reduction of hydrazones to hydrazines is readily accomplished in good yields with Et3SiH/TFA (Eq. 336).560,561 (V-Tosylimines294 are reduced to their A-Boc tosylamino counterparts,294 and are also reduced with (MeO)3SiH/LiOMe in good yields.294 Benzyl-protected hydroxylamines are reduced with PhMe2SiH/TFA.551 

In an analogous fashion to the reductive deprotection of allyl alcohols and allyl esters, the deallylation of allylamines is also possible (Eq. 337).270 

The tetrachloroferrate or tetralluoroborate salts of alkylated alkyl- or aryl-nitriles (nitrilium ions) are reduced to imines with triethylsilane. Subsequent hydrolysis of the intermediate imines leads to aldehydes in good yields, thus providing an excellent overall route to aldehydes from nitriles (Eq. 338).28,562 

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