Amines carbon-nitrogen double reduction

Fry and Newberg 1,2> examined the electrochemical reduction of nor-camphor oxime (109) and camphor oxime (110) to the corresponding amines. The results of this study are shown in Table 3. It is clear from a comparison of these data with those in Table 2 that the electrochemical reduction of oximes 109 and 110 takes a very different stereochemical course from reduction of the corresponding anils 103 and 104. Reduction of oximes apparently proceeds under kinetic control, affords products corresponding to protonation at carbon from the less hindered side of the carbon-nitrogen double bond, and affords the less stable epimeric amine in each case. It is not evident why the stereochemistry of reduction of anils and oximes should differ, however. 

N 1 C2 N II c Reduction of carbon-nitrogen double bond 1 Must belong to a primary or secondary amine group 2 Cannot be a terminal atom 2 sp Carbon... 

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. 

One of the chief values of imines is that the carbon-nitrogen double bond can be reduced to a carbon-nitrogen single bond by hydrogen in the presence of a nickel or other transition metal catalyst. By this two-step reaction, called reductive amination, a primary amine is converted to a secondary amine by way of an imine, as illustrated by the conversion of cyclohexylamine to dicyclohexylamine ... 

Reductive -elimination of A3-iodanes on carbon atoms (M = C) produces C-C double bonds, while that on oxygen and nitrogen atoms (M = O and N), combined with the initial ligand exchange reaction, provides a method for oxidation of alcohols and amines to the corresponding carbonyl compounds and imines, respectively [Eq. (26)]. 

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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