Allylamine, basicity

The basicity of the amine nitrogen appears to be an important factor for an effective asymmetric induction. Phenyl substituents on the nitrogen atom greatly retard the reaction rate. Thus, /V-phenyl- and IV.lV-diphenylgeranylamine are inert at 40°C and 24 h reaction time. Few characteristic features are worth noting. If an allylamine is secondary, the product is the corresponding imine, a more stable valence tautomer of the enamine, which cannot be detected in the reaction mixture. The exclusive formation of an ( )-enamine regardless of the double-... 

During the past decade, metal-catalyzed asymmetric reactions have become one of the indispensable synthetic methodologies in academic and industrial fields. The asymmetric isomerization of allylamine to an optically active enamine is a typical example of the successful application of basic research to an industrial process. We believe that Takasago s successful development of large-scale asymmetric catalysis will have a great impact on both synthetic chemistry and the fine chemical industries. The Rh-BINAP catalysts, though very expensive, have become one of the cheapest catalysts in the chemical industry through extensive process development. 

Moreover, the inductive contribution of a p deuterium to the IE on amine basicity was estimated.31 The inductive effect on pK due to an sp2-sp3 C-C bond, with a dipole moment of 0.35 D, as in propene, can be assigned as 0.95, the ApAf between allylamine and methylamine. Above, in connection with the structural question of the extent to which IEs affect dipole moments, dCu dco is 0.5 pm and dfi/dd is 0.004e. These combine to a ApAT on deuteration of 0.001, which is much smaller than the measured IEs in Table 5. An inductive contribution does exist, but it is negligible. 

Catalysis by acids, which is only rarely effective for aliphatic amines but better suited to the less basic aromatic amines [334], can promote nucleophilic attack at the most strongly polarized C-0 bond of the epoxide (Scheme 4.75) [333, 334, 339]. Vinyl epoxides react with amines in the presence of Pd(0) under mild conditions to yield allylamines [340], If such reactions are performed in the presence of an enantiomerically pure ligand, racemic vinyl epoxides can be converted into enantiomerically enriched products of nucleophilic ring opening (last example, Scheme 4.75). 

Hattori, A., Hattori, H. and Tanabe, K. Double-bond migration of allylamine to enamine over basic solid catalysts, J. Catal., 1980, 65, 245. 

The equilibration of allylamines like 176, which have an isolated C=C double bond, to conjugated enamines under basic conditions has been studied extensively139,292 297. With only one exception298, that of l-(indol-3-ylethyl)-3-pyrroline (181), which is only partially transformed into its enamine 182 (equation 15), the equilibrium generally lies far on the side of the enamine l-JV,JV-dimethylamino-2-propene (183) is isomerized292 with potassium terf-butoxide in DMSO, first to the Z-enamine (184) and then to the thermodynamically more stable is-enamine293,294 (185, see equation 16) as was shown by XH-NMR spectroscopy. 

Compound 1216 was then reacted with allylamine in the presence of Et3N to give A, A -diallyl-9//-carbazole-3,6-dicarboxamide 1217, subsequent treatment of compound 1217 with phosgene gave 3,6-dicarboximidoyl dichloride derivative 1218. Ring closure of dichloride 1218 was carried out under basic conditions to give 9-ethyl-3,6-di(l//-pyrrol-2-yl)-9//-carbazole 1219, a relatively low oxidation potential monomer with electron-rich pyrrole rings as terminal electropolymerizable moieties, in an overall synthetic yield of 5.8%. 

The equilibration of allylamines like 176, which have an isolated C=C double bond, to conjugated enamines under basic conditions has been studied extensively ... 

Effects of additives in the isomerization of substrate 45 by catalyst 17 were studied under the conditions of [S]=0.24 mol L [S] [C] =100 at 60 °C in THE The results are briefly summarized in Table 1, and are important both for mechanistic studies and improvements of the catalyst activity. Simple tertiary amines retard the reaction drastically, which suggests the coordination order of amines to Rh-BINAP species to be proportional with the order of basicity of simple tertiary amines, allylamines and enamines. Without the presence of simple tertiary amines, this phenomenon enables the fast replacement of the enamine formed from the catalyst by a substrate molecule that permits a smooth catalytic cycle. The presence of chelate diolefins like COD also disturbs the catalytic cycle. An over-isomerized by product, dienamine 44, acts as a strong catalyst poison. 

The reaction mechanisms for double bond isomerization of unsaturated compounds containing N and O are essentially the same as those for 1-butene isomerization. The basic sites abstract an H+ from the reactant to form allyl anion as an intermediate[7]. The reaction scheme for allylamines is shown below. In this scheme too, the intermediate of ailyl anion is more stable for cis form than for trans form, and the products are mostly in the form of cis. 

Show how one could synthesize-and resolve methylethyl-allylamine oxide from allylamine, with the knowledge that amine oxides are somewhat basic substances having... 

In this study, three different functional monomers were tested for their imprinting effectiveness. Diethylaminoethyl methacrylate (DAM) had been proven successful before. Allylamine (AA) was thought to be promising due to its basic amino functionality. Methacrylic acid (M A A) is a widely used functional monomer. In these tests it was found that DAM was the most effective monomer while MAA was not effective at all. DAM is a stronger Lewis base than allylamine, therefore, it is better able to form a complex with the hydroxyl groups on the 1,3-diol group of CAP. 

Fig. 2.4 a Schematic of the film deposition process using slides and beakers. Steps 1 and 3 represent the adsorption of a polyanion and polycation, respectively, and steps 2 and 4 are washing steps. The four steps are the basic buildup sequence for the simplest film architecture (A/ B) . The construction of more complex film architectures requires only additional beakers and a different deposition sequence, b Simplified molecular picture of the first two adsorption steps, depicting film deposition starting with a positively charged substrate. Counterions are omitted for clarity. The polyion conformation and layer interpenetration are an idealization of the surface charge reversal with each adsorption step, c Chemical structures of two t3q>ical polyions, the sodium salt of poly(styrene sulfonate) and poly(allylamine hydrochloride). Reproduced with kind permission of Ref. [32]... 

A variety of catalysts work well in hydrolyses reactions, including acids, bases, and salts. Basic catalysts give precipitated phases that are generally well-defined particles, whereas the acidic catalysts give more poorly defined, diffuse particles. - The solvent can be of considerable importance. In some cases, particles are not formed at all, and bicontinuous (interpenetrating) phases result. - Another approach uses poly(allylamine hydrochloride) in a buffered solution to obtain what was called bioinspired silica. ... 

Various combinations of synthetic polyelectrolytes are applied to the formation of polyelectrolyte shells onto colloid particles. Polyelectrolytes are divided into weak and strong ones. The examples of the first ones are sodium poly(styrene sulfonate) (PSS) and polyaniline propanesulfonic acid. Polyacrilic acid is an example of weak polyelectrolyte. Both examples are polyanions. Polyamines with various number of assistants at the atom of nitrogen are basically used as polycation components, for example poly(allylamine hydrochloride), polyethylenimin, etc. 

Beller and coworkers [142] broadened these investigations to include several other terminal-functionalized and nonfunctionalized olefins as substrates (allyl alcohols, homoallyl alcohols, allylamines, homoallylamines, vinyl cyclohexane, 3-arylprop-l-enes). For example, in a basic medium, Fe3(CO)j2 converted 1-octene cleanly into 2-octene (Scheme 5.31). Moreover, Z-2-octene was converted into the corresponding -isomer. Temperatures of80-100 °C were required to achieve nearly quantitative yields. 

Basic conditions and a nucleophilic base such as PPh3 or DABCO were required to perform the sequence SN2/[2 -I- 2]-cycloaddition displayed in Seheme 5.52 [135]. The allenyl ester 149 reacts with allylamine 150, leading to diastereomerically pure bicycles 151. 

The question of how a single polymer chain adheres to a solid surface is not only of fundamental basic interest but also related to many practical applications in materials science. In particular, as the size of devices diminishes to the nanoscale, local interfacial properties become more and more important. Small local differences in interfacial properties are also important to detea tiny contaminations. A single polymer, covalendy attached to the AFM cantilever as desaibed before, can serve as a molecular probe for adhesion. This has recently been demonstrated with a poly (allylamine) polymer as molecular probe to detect and investigate the ageing of hydrogenated and oxidized diamond.Two contributions to aging could be detected, namely a physisorption of atmospheric adsorbates on the timescale of days and conversion of surface chemical groups on the timescale of months. 

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