Amination copper-catalysed

Amine oxidase catalyses the oxidative deamination of amines to the corresponding aldehyde, hydrogen peroxide and ammonia. The copper containing amine oxidase from pig plasma (PPAO) is one of the better characterised in this class of enzyme. The homogeneously pure enzyme has a molecular weight of 190,000 composed of two subunits with equal molecular weight. The present evidence suggests that copper is essential for catalytic activity and therefore much effort has been made to determine the structure of copper sites... 

Substituted bicyclo[ . 1.0]alkanes may also be obtained by condensation of secondary amines with 2-haloketones. A variety of nucleophilic reactions can be carried out on the intermediate cyclopropaniminium salt 116251 (Scheme 108). Competing alkene scission and cyclopropanation occurs on reaction of enamines with pentacarbonyl-chromium carbene complexes252 (Scheme 109). N-Silylated allylamines and their derived N-silylated enamines undergo rhodium or copper catalysed cyclopropanation by methyl diazoacetate253 (Scheme 110). 

Shore G, Yoo W-J, Li C-J et al (2009) Propargyl amine synthesis catalysed by gold and copper thin films by using microwave-assisted continuous-flow organic synthesis (MACOS). ChemEur J 16 126-133... 

In plants, aliphatic di- and polyamines have been implicated in many processes including rapid cell division, fruit development, stress response and senescence (Evans and Malmberg, 1989 Galston and Kaur-Sawhney, 1995). Amine oxidases catalyse the eatabolism of biogenic amines and hence could be involved in regulating sueh eellular processes. It is eonve-nient to separate discussion of the roles of the copper-containing idiamine... 

Galaetose oxidase and eopper-containing amine oxidases catalyse similar reaetions the methylene group of a primary alcohol or primary amine is aetivated, a hydrogen abstracted and a product aldehyde is formed in both eases. Both enzymes eontain a single copper per active site and it would have been a reasonable prediction that the role(s) played by eopper would be similar. As we have seen (section 2.3 and 3.3), copper is essential for post-translational proeessing of tyrosine to yield novel cofactors in both oxidases and the ehemistry involved in the processing events... 

Both Me-DuPHOS (483) and Me-DuPHOS monoxide (484) have been successfully used as chiral ligands in the copper catalysed highly enantio-selective addition of dialkylzinc to N-phosphinoyl imines (485). A simple deprotection of N-protecting group from (486) provided a-chiral amines (Figure 91). ... 

The oxidative coupling uses a copper-catalysed system and a base, usually an aliphatic or heterocyclic amine, and oxygen as the oxidizing agent. In broad terms, free-radical processes are involved to explain the polymerization pathway which involves formation of the phenoxide radical, and coupling of two radicals through the attack by an oxygen-centred radical at the para position of another phenolic molecule (Scheme 25). 

A different type of ligand-coupling reactions is involved in the copper-catalysed arylation of amines. As anilines react with lead tetraacetate to afford the corresponding a-acetoxyimino derivative (see section 7.1.2.1), their reaction with aryllead triacetates could have been expected to lead to ortho-arylanilines. However, such a reaction was never observed. In fact, in the presence of a catalytic amount of a copper salt, a completely different outcome was observed. Instead of the a-C-arylation, 7V-monoarylation of anilines was observed, Moderate to good yields are generally obtained, for a variety of anilines, even for relatively hindered anilines such as mesitylamine (101), which gave high yields of the 7V-aryl products. 

The efficiency of the arylation is very dependent upon the basicity of the amines. Electron-poor anilines do not react, while electron-rich anilines give high yields of -arylation products. However, in the case of easily oxidised anilines, oxido-reduction of the aryllead reagent can compete with the 7V-arylation when the steric compression becomes too important. For example, in the case of mesitylamine (101), the copper-catalysed reaction with a variety of substituted phenyllead derivatives led to generally high yields of the diarylamines. 

Copper-catalysed arylation of heterocyclic amines such as piperidine,tetrahydroisoquinoline or l,6-diazacyclodecane204 ith aryllead triacetates gave only modest to moderately good yields of the A -aryl derivative, and the reaction with aliphatic amines led to particularly poor yields of the derived anilines. 

The copper-catalysed reactions are not so well developed but aryl bromides combine with primary amines catalysed by Cu(I) using the salicylamide ligand 115. Free OH groups are tolerated in either partner the amine or the aryl halide.33... 

A copper-catalysed amination - the Ullmann reaction - was the forerunner (1904) of all transition-metal-catalysed couplings, bnt the vigorous conditions that are required limited its use. In recent years there has been a resnrgence in copper catalysis, dne in part to the development of better ligands and understanding... 

Scheme 15.1 Copper-catalysed reactions of aromatic amines with aiyl iodides.

Scheme 15.2 Copper-catalysed reaction of an aliphatic amine with an aryl iodide.

Studies reporting substituent effects on the palladium- and copper-catalysed Sonogashira coupling reaction between an aryl iodide and an alkyne the 5 2 allylic substitution reactions between benzyl amine and racemic allyl carbonates substituted with a j -X-Ph- group on C(l) in the presence of a Rh(15,15, 2/ ,2/ -tangphos)(COD)Bp4 catalyst the stereoselective 5 2 reactions between a-substituted linear 0-ketoesters and meta- and /Jura-substituted cinnamyl carbonates generating vicinal quaternary and tertiary stereocenters in the presence of an Ir-V-arylphosphoramidite catalyst, TBD, and LiOBu-t identity vinyl halide reactions the S N... 

A direct approach to a-amino phosphonic acids derivatives (594) has been developed by McDonald and Wang. Thus, copper-catalysed electrophilic amination of a-phosphonate zincates (592) with O-acyl hydro-xylamines (593) (Scheme 172) provided the first example of C-N bond formation which directly introduced acyclic and cyclic amines (592) to the a-position of phosphonates (591) in one step. ° ... 

After its discovery in 2002, the copper-catalysed azide-allg ne dipolar cycloaddition (CuAAC) click reaction has found widespread application in glycoscience due to its broad tolerance of functional groups, offering high specificity and yield. It has found application in glycoproteins synthesis as well, for instance, in the transformation of the amine sidechain of lysine into an azide by treatment with imidazole-1-sulfonyl azide for subsequent CuAAC modification. Such methodology... 

Scheme 17.26 Zinc and copper catalysed coupling of benzylic alcohols with amines.

Enantioselective synthesis of homopropargyl amines can be effected through copper-catalysed reaction of an allenyl boron reagent with aldimines. The first nucleophilic allylation of r-electrophiles by allylboron reagents has been achieved enantioselectively using a chiral rhodium catalyst (Scheme an allylrhodium intermediate has been implicated. Similar additions of R CH=CR BF3K have also been reported. ... 

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