Poly with nucleophiles

The interaction of PCSs with nucleophilic reagents was studied by us we took the reactions of hydrazine and phenylhydrazine with polyazines, poly(schiff base)s, and other polymers containing conjupted C=N bonds as an example40,41, U7,258. ... 

Solutions of poly(dichlorophosphazene) (3.21) in benzene, toluene, or tetrahydrofuran react rapidly and completely with nucleophiles such as sodium trifluoroethoxide to yield derivative polymers as shown in reaction sequence (3). An impetus for this... 

Poly(a-chloroacrylonitrile) decomposes to low molecular weight compounds when treated with nucleophiles [A,iV-diethyldithiocarbamate (Et2NCS2 ), PhS and azide ions]. An2 SRN mechanism was suggested for this reaction, in which an ET to the polymer leads to a radical and chloride ion. Coupling with the nucleophile and decomposition are the main reactions proposed for the radical intermediates98. The reaction of 2-chloro-2-methylpropionitrile, as a model compound, with TV, A-diethyldithiocarbamate (52% yield) and PhS (61% yield) was studied98. 

Poly(phosphazenes) are also synthesized by a ring-opening polymerization of the cyclic trimer followed by substituting the chlorines with nucleophiles as shown below ... 

The course of the reaction of the poly-O-acylglycosyl halides with nucleophilic reagents has recently received attention. Thus, Lemieux has related the theories of the mechanism of replacement reactions to some reactions in carbohydrate chemistry, and has summarized our knowledge concerning the mechanism of reaction of the poly-O-acylglycosyl halides. Hence, only those aspects of the subject which have become clarified by recent work need be discussed here. 

In order to prepare hydrolytically stable polythionyiphosphazenes the perchlo-rinated polymers were reacted with nucleophiles to substitute the hydrolytically sensitive main group-element halogen bonds [2]. This type of post-polymerization structural modification is well-established in polyphosphazene chemistry [2,8]. Thus, aryloxide nucleophiles or primary amines were used to substitute the polymers leading to poly(aryloxythionylphosphazenes) 24 and poly(amino-thionylphosphazenes) 25 respectively [35,37] ... 

The grafting onto method was used to prepare graft copolymers by deactivation reaction onto a backbone fitted with nucleophilic sites. Franta et al. (134) used this technique to synthesize graft copolymers of poly(THF) with nucleophilic backbones poly( -dimethylaminostyrene) and poly(2-vinylpyridine). 

Reactivity modes of the poly(pyrazolyl)borate alkylidyne complexes follow a number of recognised routes for transition metal complexes containing metal-carbon triple bonds, including ligand substitution or redox reactions at the transition metal centre, insertion of a molecule into the metal-carbon triple bond, and electrophilic or nucleophilic attack at the alkylidyne carbon, C. Cationic alkylidyne complexes generally react with nucleophiles at the alkylidyne carbon, whereas neutral alkylidyne complexes can react at either the metal centre or the alkylidyne carbon. Substantive work has been devoted to neutral and cationic alkylidyne complexes bearing heteroatom substituents. Differences between the chemistry of the various Tp complexes have previously been rationalised largely on the basis of steric effects. 

The fundamental theory of phase transfer catalysis (PTC) has been reviewed extensively. Rather than attempt to find a mutual solvent for all of the reactive species, an appropriate catalyst is identified which modifies the solubility characteristics of one of the reactive species relative to the phase in which it is poorly solubilized. The literature on the use of PTC in the preparation of nitriles, halides, ether, and dihalocarbenes is extensive. Although PTC in the synthesis of C- and 0-alkylated organic compounds has been studied, the use of PTC in polymer synthesis or polymer modification is not as well studied. A general review of PTC in polymer synthesis was published by Mathias. FrecheE described the use of PTC in the modification of halogenated polymers such as poly(vinyl bromide), and Nishikubo and co-workers disclosed the reaction of poly(chloromethylstyrene) with nucleophiles under PTC conditions. Liotta and co-workers reported the 0-alkylation of bituminous coal with either 1-bromoheptane or 1-bromooctadecane. Poor 0-alkylation efficiencies were reported with alkali metal hydroxides but excellent reactivity and efficiencies were found with the use of quaternary ammonium hydroxides, especially tetrabutyl- and tetrahexylammonium hydroxides. These results are indeed noteworthy because coal is a mineral and is not thought of as a reactive and swellable polymer. Clearly if coal can be efficiently 0-alkylated under PTC conditions, then efficient 0-alkylation of cellulose ethers should also be possible. 

Polycarbophosphazenes possess a backbone of phosphorus, nitrogen, and carbon atoms and can be regarded as derivatives of classical polyphosphazenes (1) in which every third phosphorus atom is replaced by carbon. The first examples of these materials were discovered in 1989 (88). Thermal ROP of a cyclic carbophos-phazene was used to prepare the chlorinated polymeric species (23), which im-dergoes halogen replacement reactions with nucleophiles such as aryloxides and aniline to yield hydrolytically stable poly(aryloxycarbophosphazenes) (24) (Afw = ca 10 , Mn = 10 ) (eq. 23) (88-91). The polymer backbone in these materials was found to be less flexible than in classical polyphosphazenes. For example, the halo-genated polymer (23) possesses a Tg of —21°C compared to a value of —66°C for poly(dichlorophosphazene) (2). 

Wudl et al. polymerized isothianaphthene (81) electrochemically [140]. The products were strongly dependent on electrolytes used in the polymerization. While in the presence of a non-nucleophilic anion salt such as LiBp4, electrochemical polymerization gave a white powder composed of poly(dihydroisothiana-phthene). Poly (isothianaphthene) was produced with nucleophilic anion salts such as LiBr, (C6H5)4AsCl and H2SO4. TCNQ and chloranil were also used in the polymerization. 

TMS group frequently rrsed as a protective group for OH groups. Poly(glyddyl acrylate) copolymers can be prepared by ATRP to serve as a precursor of functional polymers, since the pendant glyddyl group can react with nucleophiles and... 

These polymers can be prepared by several teclmiques, but the route utilized most in this work is summarized in Scheme I. It is based on the use of a reactive macromolecular intermediate - poly(dichlorophosphazene) (3), which can be produced either by the ring-opening polymerization of compound 2 or by the living cationic polymerization of 4. Replacement of the chlorine atoms in 3 by organic side units is accomplished by treatment of 3 with nucleophiles, such as the sodium salts of alcolK>ls or phenols or with primary or secondary amines. Two or more different side groups can be introduced into the same macromolecule by simultaneous or sequential exposure to the two nucleophiles. 

Preparation of a macromolecular precursor, poly(dichlorophosphazene) (PDCP), which is then reacted with nucleophilic reagents to replace all the chlorine atoms... 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

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