Benzylic amination, copper-catalyzed

We observed a more complicated behavior in the study of retarding action of amines (IV-benzyl-IV -phenyl-l,4-benzenediamine and 4-hydroxyphenyl-2-naphtalenamine) on fuel T-6 oxidation catalyzed by the copper powder [13]. Both antioxidants appeared to retard the autoxidation of T-6 very effectively. They stop chain oxidation during the induction period in concentrations equal to 5 x 10 5mol L 1 and higher. The induction period was found to be the longer, the higher the concentration of the antioxidant and lower the amount of the copper powder introduced in T-6. 

Azines have been benzylated via the corresponding organostannanes [91, 109, 110], and alkylated or arylated via the organocuprate precursors [111-113]. Vinyla-tion of isoquinolines or quinolines with alkenylzirconocene chlorides 116 proceeds in excellent yields. Interestingly, an analogous reaction of a reduced derivative, catalyzed by a copper (1) salt in the presence of a chiral amine ligand, furnishes the corresponding adduct 117 in an enantioselective manner. (Scheme 17) [114]. 

This new disilver system was found to be more active in intramolecular amidation reactivity compared to the original [Ag2(t-Bu3tpy)2] catalyst, showing both increased yields and decreased temperature (from 82 to 50°C). More importantly, this system was able to catalyze the intermolecular amination reaction of both benzylic and inert aliphatic C—Hbonds.Asimilar copper system reported similar activity however, it was only able to aminate benzylic C—H bonds (Table I). In the silver case, it was found that substitutions on the 2 and 9 positions of the phenanthroline shut down the reactivity of the catalyst, suggesting the importance of keeping a disilver core structure. 

A one-pot copper(I)-catalyzed tandem azidation of ort/io-bromo-benzyl(propargyl)amines and an azide-alkyne 1,3-dipolar cycloaddition reaction, afforded [l,2,3]-triazolo[l,5-a][l,4]benzodiazepines (13T4331). 

In 2012, Ravasio and co-workers also reported an additive-free A-alkylation of amines with benzyl and aliphatic alcohols catalyzed by C11/AI2O3 [161]. In 2014, the authors extended the method to the iV-alkylation of anilines with a wide range of alcohols (Eq. 47) [162]. In 2013, Mishra and co-workers reported an additive-free A -aUcylation of primary amines with primary and secondary alcohols catalyzed by copper-aluminium hydrotalcite (CuAl-HT) [163]. 

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