Amines palladium reactions

Palladium, (diammine)bis(thiocyanato)-isomerism, 1, 185 Palladium, dichlorobis(amine)-substitution reactions stereochemistry, 1, 318 Palladium, dichlorobis(pyridine)-substitution reactions, 1, 314 Palladium, dinitritobis(triisopropylphosphine)-substitution reactions, I, 314 Palladium, ethylene-synthesis... 

A dry two-neck flask was charged with amine (1.00 mmol), triflate or bromide (1.20 mmol), base (1.40 mmol), ligand (10 mol%), palladium acetate (Pd(OAc)2) or tris-(dibenzylidene-acetone)dipalladium (0) (Pd2dba3) (5 mol%), and toluene (2.00 mL/mmol of amine). The reaction was flushed with N2 and heated at 80 °C. The mixture was diluted with ether, filtered through a pad of Celite, and the volatile components were removed reduced pressure to give a crude product, which was purified by flash column chromatography on silica gel. 

Now, let s go back to the salmefamol synthesis we started with on p. 617. The other reducing agent used in the sequence is hydrogen gas over a palladium catalyst. Catalytic hydrogenation has two functions here firstly, it removes the two benzyl groups from the nitrogen, revealing a primary amine (this reaction is discussed later in this chapter), and, secondly, it reduces the imine that forms between this amine and... 

Reaction of dichloro(2,2,Ar,A-tetramethyl-3-buten-l-amine)palladium-(II) with CH2N2 gives the carbene insertion product, a-chloro-A-(chloromethyl)-c/,c-(2,2,jV,7V-tetramethyl-3-buten-l-amine(palladium(II)) (56), together with analogous ethoxymethyl and methyl complexes (127). 

Additional reactions which need to be highlighted are the reductive alkylation of alcohols and amines with aldehydes leading to the green synthesis of ethers and amines. These reactions are generally catalyzed by palladium [35]. This reaction can replace the classical Williamson s synthesis of ethers which requires an alcohol and an alkyl halide together with a base, and always results in the concomitant production of salt. The choice of Pd/C as catalyst is due to the low efficiency of this metal for the competitive carbonyl reduction. Analysis of the... 

Guram has reported similar P,N- and P,0-chelating ligands useful in the amine arylation reaction [47]. For example, the coupling of piperidine with 4-bromobenzophenone proceeds in 98% yield with as little as 0.5 mol% of the palladium catalyst resulting from ligand 5, Eq. (17). 

The hydroamination reactions which are assisted or catalyzed by transition metal species can be utilized in the cyclization of unsaturated amines. Palladium(II) is not recommended for such transformations, since low yields were obtained even using stoichiometric amounts of palladium chloride47. Since an enamide is formed by /J-hydride elimination, a reduction step must be performed to obtain the saturated nitrogen heterocycle. A catalytic cyclization reaction, analogous to the Wacker process, was performed from /V-alkenyl tosylamides, such as 1, using... 

The hydrogenation of azoxy benzenes occurs in a stepwise fashion to give the azo and hydrazo compounds with final hydrogenolysis to the amine. The reaction can be stopped at any of these stages over W2 Raney nickel at room temperature and atmospheric pressure. With platinum oxide the hydrazine is obtained in very good yield. Hydrogenolysis to the amine occurs over all common metal catalysts but takes place most readily with palladium. 

Addition of a variety of nucleophiles to rf-alkene and alkyne ligands has been investigated, particularly when these ligands are complexed with iron and palladium. Reactions shown in equation 8.39 demonstrate well the typical stereochemistry resulting from the trans mode of attack by external nucleophiles on t 2—7t systems.56 Careful analysis of the reaction of amines with ( )- and (Z)-2-butenyl iron complexes (the CpFe(CO)2 group is abbreviated Fp, which is pronounced fip ) showed the stereochemistry to be cleanly anti.51... 

---