Amines Organocopper reagents

Scheme 2.30 Ring-opening reaction with organocopper reagents to form (E)-allyl 111 amines.

Addition of organocopper reagents to imine derivatives can readily afford functionalized amine derivatives. Three recent examples are shown below (Equations (129) and (130) Scheme 102).498,498a,498b In these cases, iminium ions are employed as an activated imine. 

Scheme 3.34. Alkylation or arylation of amines by treatment of organocopper reagents with amines [119].

Chiral aminals 1,4-dihydropyridine-3-carboxaldehydes.1 The chiral aminal 2 prepared from pyridine-3-carboxylaldehyde and (S,S)-12 reacts with organocopper reagents in the presence of methyl chloroformate to give almost exclusively products of 1,4-addition, as expected from reactions of the free aldehyde.3 No products of 1,2-addition are formed, but 1,6-adducts are minor products in some cases. The 1,4-adducts are formed in 82-93% de (R-configuration). Addition of butyl and ethyl groups is best effected with lithium cuprates, but addition of methyl, vinyl, or aryl groups is best effected with organomagnesium cuprates. Under these conditions,... 

Attempts to induce asynunetry at an imine carbon using homochiral amines to form Schiff bases followed by 1,2-additions with organocopper reagents has not produced a viable method as yet. Yamamoto... 

Organocopper reagents are the most reliable species for conjugate additions and a number of approaches towards chiral cuprates has been developed. The approaches are classified into two categories one is the chiral heterocuprate obtained by treatment with chiral alcohols, amines, sulfonamides, and thiols. The other involves organocopper compounds coordinated by chiral external ligands such as phosphines, sulfides, and oxazolines. 

N-AlkylationJ Lithiated amines form amidocuprates with organocopper reagents. Treatment with oxygen accomplishes the transfer of an organic residue from copper to nitrogen. 

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