Telechelic amines, synthesis

Amine, telechelic, synthesis, 139-145 Amine end-group functionality, primary, synthesis, 140-143... 

We have previously reported the results of careful investigations of the solution carbonation (8) and oxidation (9) of polymeric organolithium compounds. These studies have been extended to the investigation of solid-state carbonation reactions and these results are reported herein. In addition, a new method has been developed for the synthesis of telechelic polymers with primary amine end-group... 

The successful synthesis of such materials requires that, Initially, telechelic tertiary amine terminated polybutadiene be prepared quantitatively. Alternative routes are therefore being sought, two of which are outlined In this paper. 

ADMET depolymerizations with substituted alkenes have been done as well, thereby generating perfectly difunctional telechelic molecules. As an example, 1,4-polybutadiene has been depolymerized in an inert atmosphere with a 10-fold molar excess (based on the repeat unit) of either allyltrimethylsilane or allylchlorodimethylsilane (equation 23). In these examples, the chemistry can be driven to complete depolymerization to yield structures with either one, two, three, or four repeat units of 1,4-butadiene. The synthesis of perfectly difunctional oligomers by this chemistry offers significant opportunity, particularly for functional groups such as alcohols, esters, carboxylic acids, and amines. 

The first part concludes with a discussion of the similarity between the mechanisms of initiation and chain transfer, the appreciation of which led to the inifer concept, which in turn yielded new telechelics, networks, sequential copolymers, etc. The second part of this presentation focuses on practical consequences of understanding details of the mechanism of initiation. The synthesis of a new family of telechelic linear and tri-arm star polyisobutylenes will be described. Among the new prepolymers are telechelic olefins, epoxides, aldehydes, alcohols, and amines. The preparation of new ionomers and polyisobutylene-based polyurethanes will be outlined and some fundamental properties of these new materials will be discussed. 

A one-pot synthesis of telechelic and semitelechelic poly(alkyl acrylates) with unsaturated end groups has been developed by Bielawski et al. [1]. ATRP of methyl acrylate or -BA was initiated with either ethyl cy-bromomethyl-acrylate or methyl dichloro acetate, as a monofunctional or a difunctional initiator, respectively, and was mediated with various Cu-amine complexes. Addition of excess ethyl 2-bromomethylacrylate was found to immediately quench the polymerization, but also to insert 2-carbethoxyallyl moieties at the ends of the polymer chains (Scheme 24). Thus, the synthesis of telechelic poly(alkyl acrylates) with unsaturated end groups has been accomplished, with very good functionality (f 2) (Scheme 24). 

In spite of the relatively low performance/cost ratio of the respective products, application of reactions on polymers are of continuous interest for synthesis of amine functionalized polymers. The technique of modification of solid polymers by exploitation of their reactive moieties under heterogeneous conditions allows properties to be tailored and optimized according to specific needs and requirements. Telechelic polymers are used for the synthesis of materials with predictable and controlled properties. Application of carefully designed macromolecules provides systems with functional groups dispersed along the polymer chain or bond at the end of macromolecules. 

Telechelic prepolymers having epoxide end-groups as well as telechelics containing amino end-groups and cyclooligomers were foxmd in the FAB mass spectra of epoxy-amine addition polymers. An FAB-MS study characterized in detail the oligomeric products formed in the synthesis of Novalak-type resin. ... 

Chakraborty, R. Soucek, M. D., Synthesis of Amine and Epoxide Telechelic Siloxanes. Macromol. Chem. Phys. 2008, 209, 604-614. 

The growing living species 1 can be quenched cleanly with so-diomalonic ester to form the target hetero-telechelic polymers (17). The terminal (head) function X (arising from 1 ) may be acetate or imide that in turn leads to a carboxylic acid or an amine, respectively. Another terminal carries a malonate (from the malonate terminator), which can be converted to a carboxylic acid by hydrolysis/ decarboxylation. One of the advantages of the polymer synthesis via the base-stabilized species is the rather high operational temperature up to +60 °C. 

For nitroxide-mediated radical polymerizations and in the RAFT process, the same synthetic strategy as for ATRP can be used in the synthesis of AB and ABA block copolymers. The first step is coupling a functionalized alkoxyamine with a telechelic or monofunctional nonvinylic polymer to give a macroinitiator. This macroinitiator can be used in standard controlled free-radical polymerization procedures. This approach is best illustrated by the preparation of PEO-based block copolymers [81-84]. One example is the preparation of macroinitiator LMI-7 by the reaction of a monohydroxy-terminated PEO with sodium hydride followed by reaction with the chloromethyl-substituted alkoxy amine as shown in Scheme 3.16. 

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