Vinylpyridines amines

The Zincke reaction has also been adapted for the solid phase. Dupas et al. prepared NADH-model precursors 58, immobilized on silica, by reaction of bound amino functions 57 with Zincke salt 8 (Scheme 8.4.19) for subsequent reduction to the 1,4-dihydropyridines with sodium dithionite. Earlier, Ise and co-workers utilized the Zincke reaction to prepare catalytic polyelectrolytes, starting from poly(4-vinylpyridine). Formation of Zincke salts at pyridine positions within the polymer was achieved by reaction with 2,4-dinitrochlorobenzene, and these sites were then functionalized with various amines. The resulting polymers showed catalytic activity in ester hydrolysis. ... 

Reaction of 9-bromo-2-morphohno-4//-pyrido[l, 2-n]pyrimidin-4-ones with 4-vinylpyridine in DMF at 80 °C for 16 h in the presence of CS2CO3 and PdCbCdppf), and with amines and phenols in boiling THF for 20 h in the presence of KOr-Bu and PdCbCdppf) yielded 9-[2-(4-pyridyl)vinyl), 9-(substituted amino), and 9-aryloxy derivatives, respectively (01MIP9). 4-Hydroxyaniline gave a 9-(4-hydroxyphenyl)amino derivative. 

A great variety of suitable polymers is accessible by polymerization of vinylic monomers, or by reaction of alcohols or amines with functionalized polymers such as chloromethylat polystyrene or methacryloylchloride. The functionality in the polymer may also a ligand which can bind transition metal complexes. Examples are poly-4-vinylpyridine and triphenylphosphine modified polymers. In all cases of reactively functionalized polymers, the loading with redox active species may also occur after film formation on the electrode surface but it was recognized that such a procedure may lead to inhomogeneous distribution of redox centers in the film... 

If the more activated alkene 2-vinylpyridine is used in place of styrene with the same catalysts and the same range of substrates, anti-Markovnikoff hydroamination is also found. Thus, N-[2-(2 -pyridyl)ethyl]piperidine was isolated in 53% yield from reaction of 2-vinylpyridine with piperidine in the presence of [Rh(COD)2]+/2PPh3 under reflux. N H addition was observed with other amines, the remaining product in all cases being primarily that from oxidative amination (Table 12). When the catalytic reaction was run in the absence of phosphine, the yield of hydroamination product increased dramatically.171... 

Mdleleni and coworkers137 anchored RhCl3 onto several porous aminated polymers. As displayed in Table 43, the best polymer support was found to be poly (4-vinylpyridine). Conditions T = 100 °C Pco = 0.9 atm RhCl3 3H20 = 5 x 10 5 mol solvent/H20 = 4/1 v/v. 

One of the first examples of this type of blend was composed of SPEEK or SPES as the acidic component and diaminated PES, poly(4-vinylpyridine) (P4VP), poly(benzimidazole) (PBl), or poly(ethyleneimine) (PEI) as the basic component. " For blend lEC values of 1.0 meq/g, conductivity values were reported to be good, as was H2/O2 EC performance. Thermal stabilities for these blends was also demonstrated to be high (>270°C). Other examples of acid-base PEMs include blends of SPPO and PBI, sulfonated poly(phthalazinone ether ketone) and aminated SPES, SPIs and aminated Pls, and SPEEK with PES bearing benzimidazole side groups, ° as well as an unusual example in which the blend is composed of sulfonated, hyper-branched polyether and pyridine-functionalized polysulfone. ... 

We describe below the change in catalytic behavior when an amine ligand (L) is substituted by a polymer ligand. The Cu(II) complexes of poly(4-vinylpyridine) (PVP), partially quaternizedPVP(QPW) 18, partially diethylaminomethylated poly (styrene) (PDA) 53, and poly(ethyleneimine) proved effective as catalysts in the... 

Vinyl groups a or y to the pyridine nitrogen atom readily undergo Michael additions. Water, alcohols, ammonia, amines and hydrogen cyanide are among the nucleophiles which may be added. For example, 2-vinylpyridine and dimethylamine give the adduct (701 X = NMe2). 

Chloroindolizine is formed in a reaction of 2-vinylpyridine with dichlorocarbene (77ACS(B)224). Af,(V-Disubstituted 3-aminoindolizines have been obtained from a reaction of 2-bromopyridine, propanol and secondary amines (79CL24 l). Irradiation of N- phenylpyr-role and N-methyldibromosuccinimide in benzene gave 18% of the indolizine (187) (80CB2884). 

Thomas, T. J. et al., Amer. Inst. Aero. Astron. J., 1976, 14, 1334—1335 Ignition temperatures were determined by DTA for the perchlorate salts of ethyl-amine, isopropylamine, 4-ethylpyridine, poly(ethyleneimine), poly(propyleneimine), and poly(2- or 4-vinylpyridine). In contrast to the low ignition temperatures (175— 200°C) of the polymeric salts, mixtures of the polymeric bases with ammonium perchlorate decompose only above 300°C. 

The different situations of the block copolyampholyte as a function of pH are depicted in Scheme. 1. The same order of deprotonation was observed in copolymers of poly(methacrylic acid) and poly(2-(diethylamino)ethyl methacrylate) [70, 71, 72, 75-77]. In copolymers of poly(methacrylic acid) [78] and poly(2/4-vinylpyridine), on the other hand, deprotonation of the pyridine hydrochloride takes place prior to deprotonation of the carboxyl [79-83] because in comparison to carboxylic functionalities amine hydrochlorides are the weaker acids and vinylpyridinium hydrochlorides the stronger ones. Thus, in the latter systems an isoelectric point (iep) is not observable, while in the first case polyzwitterions are formed which possess the highest amount of charges at that pH resulting in a polyelectrolyte complex (PEC). In the second case polymers with a minimal net charge built the PEC which is stabilized by hydrophobic interactions often accompanied by hydrogen bonding [79, 84-88]. 

Amine functions readily react with oxonium sites. This reaction was used for the synthesis of graft copolymers involving reaction of living poly-THF with either poly(p-vinylpyridine) or poly(p-dimethylaminostyrene) S6K Attempts to synthesize macromonomers by a similar route were made57 but their characterization is difficult because they contain quaternary ammonium sites ... 

CPB2044). However, much more interesting are two further technical syntheses of the important nucleophilic catalyst DMAP (228) and related 4-aminopyridines. Treatment of 4-cyanopyridine (274), produced on a technical scale by ammonoxidation of y-picoline, with 2-vinylpyridine (275) in the presence of hydrochloric acid gives the crystalline quaternary salt 276. This salt is readily aminated by an aqueous solution of dimethyla-mine at room temperature with liberation of cyanide. The resulting aminated quaternary salt is finally cleaved by 40% NaOH to DMAP (228) and 2-vinylpyridine (275), which is recycled after separation of228 and 275 by distillation (79USP4I58093). 

The conversion of pyridine by thionyl chloride to 4-pyridyl-pyridinium chloride hydrochloride (65), followed by heating in DMF as solvent and reactant to afford DMAP (228) and pyridine, was the first commercial process to give DMAP (228) in ton amounts at reasonable prices. Amination of 4-pyridylpyridinium chloride hydrochloride with pyrrolidine also furnishes PPY (184) directly (cf. Section IV,H). Alternatively, the inexpensive 4-cyanopyridine (274) is quaternized by either 2-vinylpyridine-HCI or acrylamide-HCI and readily aminated with dimethyl-amine or pyrrolidine to give, after alkaline treatment, DMAP (228) or PPY (184) (cf. Section V,A). 

A broad range of functional monomers and cross-linkers has been used for the preparation of MIPs. The choice of the functional monomers depends on the nature and functionalities of the print molecule. The most widely used monomer is methacrylic acid, which has been shown to interact through ionic interactions and hydrogen bonds with amines, amides, carbamates and carboxylic acids [13-15]. The monomers and the print molecules self-assemble upon mixing and the strength of the complex is of importance for the selectivity of the polymer. For this reason, a considerable amount of research effort has focused on finding optimal monomers for various classes of print molecules and functionalities. For example, for some print molecules, polymers prepared with vinylpyridines [16,17], 2-(trifluoromethy-l)acrylic acid [18] or acrylamide [19] resulted in higher selectivities and affinities than polymers made from methacrylic acid. Mixtures of functional monomers... 

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