Recall that formation of an imine is best done under mildly acidic conditions (pH 4 or 5).
Reduce the imine with a reductant such as sodium cyanoborohydride (NaBH3CN sodium borohydride (NaBH4 dossier inscription concours aide soignante narbonne or sodium tri-acetoxyborohydride (NaBH(OAc)3) giving a new amine.
For our purposes, they can be considered to be the same.
A Lewis acid-catalyzed three-component, mild, highly atom econocial, direct-type Mannich reaction of simple aromatic and enolizable aliphatic aldehydes, secondary amines, and glycine derivatives affords various synthetically important anti,-diamino ester derivatives in high yields with high diastereoselectivities.
Stannous chloride catalyzes a chemoselective reductive amination of various carbonyl compounds with aromatic amines using inexpensive polymethylhydrosiloxane as reducing agent in methanol.The selective aldimine cross-coupling represents a simple and flexible method for the synthesis of highly substituted unsymmetrical 1,2-diamines.In short, reductive amination is a very powerful and useful protocol for the formation of amines. What if the NaBH4 ends up reducing the aldehyde or ketone before it has a chance to react with the imine?Note that the carbon attached to the nitrogen doesnt have a C-H bond.Chen, Synthesis, 2017,.Aldehydes and ketones were easily converted to the corresponding amines by the reaction of amines in methanol using decaborane (B10H14) at room temperature under nitrogen.Heres a more versatile way to make amines that doesnt result in over-alkylation.Reminder: Alkylation of Amines Is Rarely The Answer.In the schemes below, well use NaBH3CN, but NaBH4 and NaBH(OAc)3 can be considered to work just as well.
The derived N -alkylated o -chloroarylamines were elaborated to N -alkylazaindoles and N -alkylindoles via a novel one-pot process comprising copper-free Sonogashira alkynylation and a base-mediated indolization reaction.
An experimentally simple Microwave-assisted reductive alkylation of methyl carbamate with a range of aldehydes provides, after basic work-up, structurally diverse primary amines.
Starting with an aldehyde or ketone, form an imine (the nitrogen analog of an aldehyde or ketone).
Theres no need to isolate the intermediate imine (which tend to be somewhat unstable anyway the reduction can be performed in situ (i.e.There are two other commonly used reductants for reductive amination: sodium cyanoborohydride (NaBH3CN) and sodium tri-acetoxyborohydride (NaBH(OAc)3 ).If a molecule contains both an amine and a carbonyl, then it can cyclize to give a cyclic amine.Alkynes reductive amination wont work.One must resort to alternative techniques.That means that there are three possible ways of making this amine through reductive amination, all of them acceptable!It is connected to three carbons, which we can label a, b, and.