2- Amino-4-picoline, reaction with

The authors used a new type of substrate, e.g., 2-amino-3-picoline 7.1, which produces conventional substrates 12, which, in turn, form a five-membered ring 7.3 during a reaction with one component, such as an aldehyde. Other components, such as 1-alkenes, coordinate to the metal atom. Finally, the product 7.4 is formed by the couphng of l-aUcenes and aldehydes at the rhodium catalyst. 

Reaction of 2-amino-3-picoline (145) with 4-phenylsulfonyl-tetrafluoropyridine (147) was less selective than the reactions described above and three major... 

Mixed donor ligands. The complex [FeL3]Cl3 (L = acetylhydrazine) contains the ligand in its bidentate form, bonded via the carbonyl and primary amino-groups.Pyridine-2-carboxaldehyde and l,l,l-tris(aminoethyl)ethane react with Fe" via a template reaction to form [Fejlpyljltame) ], in which three molecules of carboxaldehyde have condensed with one molecule of triamine to produce (pyljltame). MeC(CH2N=CH-oc-py)3 the complex cation is octahedral. The complexes [FeL ] (L = l,10-phenanthroline-2-carboxamide, n = 1 or 2) have been isolated they are both six-co-ordinate. Very weak d-d bands have been identified in the spectra of complexes of ot-picolinic acid and quinaldic acid with Fe". ... 

Optimized reaction conditions call for the use of Wilkinson s catalyst in conjunction with the organocatalyst 2-amino-3-picoline (60) and a Br0nsted add. Jun and coworkers have demonstrated the effectiveness of this catalyst mixture for a number of reactions induding hydroacylation and C—H bond fundionalization [25]. Whereas, in most cases, the Lewis basic pyridyl nitrogen of the cocatalyst ads to dired the insertion of rhodium into a bond of interest, in this case the opposite is true - the pyridyl nitrogen direds the attack of cocatalyst onto an organorhodium spedes (Scheme 9.11). Hydroamination of the vinylidene complex 61 by 3-amino-2-picoline gives the chelated amino-carbene complex 62, which is in equilibrium with a-bound hydrido-rhodium tautomers 63 and 64. 

The reaction of isothiocyanate 2 and 30 with 2-amino-4-picoline has also been reported.55 Dorn and coworkers56"59 reported the synthesis of a number of substituted thioureido derivatives by treatment of isothiocyanates 2 and 5 with 2-phenylethylamine, bis(2-chloroethyl)amine, and 2-(4-ethoxyphenyl)-1 -phenylethylamine. 

Hydro acylation of alkenes was achieved in the presence of Wilkinson s catalyst and microwave irradiation under solvent-free conditions. As an example, benzaldehyde was reacted with dec- 1-ene to give 1-phenylundecan- 1-one in 83%yield within 30 min. Both domestic microwave ovens and single-mode reactors have been used for this reaction. The presence of an amine such as 2-amino-3-picoline or aniline and a carboxylic acid is crucial for the success of the reaction, showing that the formation of an imine plays an important role as an intermediate in the mechanism of this reaction29. 

A primary alcohol and amines can be used as an aldehyde precursor, because it can be oxidized by transfer hydrogenation. For example, the reaction of benzyl alcohol with excess olefin afforded the corresponding ketone in good yield in the presence of Rh complex and 2-amino-4-picoline [18]. Similarly, primary amines, which were transformed into imines by dehydrogenation, were also employed as a substrate instead of aldehydes [19]. Although various terminal olefins, alkynes [20], and even dienes [21] have been commonly used as a reaction partner in hydroiminoacylation reactions, internal olefins were ineffective. Recently, methyl sulfide-substituted aldehydes were successfully applied to the intermolecu-lar hydroacylation reaction [22], Also in the intramolecular hydroacylation, extension of substrates such as cyclopropane-substituted 4-enal [23], 4-alkynal [24], and 4,6-dienal [25] has been developed (Table 1). 

The addition of a catalytic amount of Cp2TiCl2 dramatically increases the yield of the hydroacylated ketone formed in the hydroacylation of 1-alkenes with heteroaromatic aldehydes by using Wilkinson s complex and 2-amino-3-picoline as co-catalysts.1264 Cp2TiCl2 catalyzes the reduction of aryl halides by sodium borohydride. The reaction scope and mechanism are solvent dependent.1265... 

A similar reaction, the rearrangement of m-phenylenediamine was patented by Bayer (Figure 1) [6]. In this patent, a much higher conversion and a better selectivity than obtainable with aniline was reported. Two reaction mechanisms were proposed for the aniline rearrangement reaction [3,7]. In this contribution, we will discuss this interesting reaction and report on some studies on process variables and on the reaction mechanism. As a model compound, we used m-phenylenediamine because of the higher conversion and relatively milder reaction conditions required for its conversion into 2-amino-6-methylpyridine (a-amino-a -picoline). 

To explain this result, it may be assumed that the transrmination by reaction of the starting imine, 1, with 2-amino-3-picoline, 2, might be the rate-determining step. In such a situation, the transition state is expected to be more polar and, therefore, sensitive to MW dipole-dipole stabilization. The qualitative polarities between ground and transition states have been determined by PM3 computations, and clearly showed the enhancement of the polarity during the process (Eq. 19) ... 

While enynes are common products in the reaction of 1-alkynes under Wilkinson s catalyst, hydrative dimerization products of 1-alkyne with H2O are obtained in the presence of an additional cocatalyst, 2-amino-3-picoline. For instance, when the reaction of terminal alkynes and FI2O is carried out using the catalytic system of RhCl(PPh3)3, 2-amino-3-picoline, and benzoic acid in THF, a mixture of branched a,/3-enone and linear enone can be obtained in a 4 1 ratio (eq 81). ... 

Another intramolecular synthesis of carbazoles 270 employed amino biaryls 269 as the starting materials with 2-picolinic acid as a directing group to facilitate a net C—H amination reaction under copper catalysis in the presence of Mn02 and acetic acid. The directing group is removed spontaneously after the initial amination (140L2892). 

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