Catalysts secondary amine

Secondary amines have been converted to tertiary amines by treatment with lithium dialkylcuprate reagents R2CuLi -t- NHR RNR2 The reaction was also used to convert primary amines to secondary, but yields were lower. However, primary aromatic amines (ArNH2) were converted to diaryl amines (ArNHPh) by treatment with Ph3Bi(OAc)2 and a copper powder catalyst. 

With the exception of intramolecular amination reactions, all of the early aryl halide aminations were catalyzed by palladium complexes containing the sterically hindered P(o-tol)3. In papers published back-to-back in 1996, amination chemistry catalyzed by palladium complexes of DPPF and BINAP was reported.36,37 These catalysts allowed for the coupling of aryl bromides and iodides with primary alkyl amines, cyclic secondary amines, and anilines. 

Highly enantioselective organocatalytic Mannich reactions of aldehydes and ketones have been extensively stndied with chiral secondary amine catalysts. These secondary amines employ chiral prolines, pyrrolidines, and imidazoles to generate a highly active enamine or imininm intermediate species [44], Cinchona alkaloids were previonsly shown to be active catalysts in malonate additions. The conjngate addition of malonates and other 1,3-dicarbonyls to imines, however, is relatively nnexplored. Snbseqnently, Schans et al. [45] employed the nse of Cinchona alkaloids in the conjngate addition of P-ketoesters to iV-acyl aldimines. Highly enantioselective mnltifnnctional secondary amine prodncts were obtained with 10 mol% cinchonine (Scheme 5). 

Secondary and Primary Amine Catalysts for Iminium Catalysis... 

Formation of C-C bonds remains the ultimate challenge to the synthetic chemist. The employment of new synthetic methods in complex target synthesis can be frustrated by a lack of functional group tolerance and substrate specificity. These problems can be somewhat alleviated within conjugate addition reactions by the use of secondary amine catalysts where a number of important and highly selective methods have been developed. Two principle classes of nucleophile have been shown to be effective in the iminium ion activated conjugate addition of carbon nucleophiles to a,P-unsaturated carbonyl systems aryl, heteroaromatic and vinyl... 

They tried Ni catalysts with chelating amine and phosphine ligands in the reaction of phenylzinc bromide with A-benzoyloxymorpholine 2a and observed that in the presence of NiCl2(PPh3)2, n-alkyl, aryl and functionalized arylzinc chlorides can be aminated with A,A-disubstituted O-benzoylhydroxylamines in good yields (Schemes 20 and 21). Attempted amination of secondary and tertiary alkylzinc chlorides failed to yield the expected product. 

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