Nitrogen=carbon double bonds, reductions, sodium

Many aldehydes (RCHO) and ketones (R2CO) are converted into amines by reductive amination reduction in the presence of ammonia. Reduction can be accomplished catalytically or by use of sodium cyanohydridoboratc, NaBHjCN. Reaction involves reduction of an intermediate compound (an imine RCH NH or R2C NH) that contains a carbon-nitrogen double bond. 

The carbon-carbon double bond is essentially nonpolarized in the rest state, even though, under the influence of an approaching molecule, it is highly polarizable, especially in aromatic systems. When a permanent polarization is introduced, as is the case when carbon is doubly bonded to oxygen or nitrogen, the addition of sodium is greatly facilitated. The carbonyl group provides the most familiar illustration. The sodium reduction of esters is a classic example ... 

Nanoparticles passivated by metal-carbon double bonds have also been achieved and exemplified by ruthenium nanoparticles. The synthetic procedure is somewhat different from the biphasic route detailed. Here, ruthenium colloids are first prepared by thermolytic reduction of ruthenium chloride in 1,2-propandiol in the presence of sodium acetate. A toluene solution of diazo derivatives is then added, where the strong affinity of the diazo moiety to a fresh ruthenium surface leads to the formation of ruthenium-carbene n bonds and the concurrent release of nitrogen. The resulting particles become solnble in toluene and can be purified in a typical manner. ... 

Reduction of groups attached to amines (aromatic rings and carbon-carbon double and triple bonds) can be effected by methods previously discussed. These include (a) catalytic hydrogenation with hydrogen gas (H2) over a metal catalyst such as platinum (Pt), nickel (Ni), or palladium (Pd) (Equation 10.37) and (b) dissolving metals such as sodium (Na) in an alcohol solvent/reactant (Equation 10.38). Some nitrogenous materials have been known to poison some catalysts and thus experimentation is often necessary. 

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