Multi-maleimide

Watanabe M, Yoshie N (2006) Synthesis and properties of readily recyclable polymers from bisfuranic terminated polyethylene adipate) and multi-maleimide linkers. Polymer 47 4946 1952... 

Re-mendable polymers can achieve multiple healing cycles, but require external intervention in the form of heat treatment and applied pressure. It is a powerfiil method of crack reparation for polymers that exhibit thermally reversible reactions for cross-linking linear chains. For example, a Diels-Alder polymerization product of reaction between a multi-furan and multi-maleimide has shown to be feasible and a recovery of about 57% of the original fracture load has been obtained. Other types of organic adhesives are not capable of repolymerizing, and alternative self-healing procedures should be employed. 

The extension of these DA-hased polymerizations to multi-functional furan and/or maleimide monomers naturally leads to crosslinked materials, whose original feature is related to the fact that they can be readily decrosslinked by a simple thermal treatment. Since the first report of a mendable material based on this principle, but applied in cycles [69], several similar studies have appeared in the literature [64] including interesting applications in the realm of thermally removable foams [64] and adhesives [64]. It seems likely that such a simple and useful strategy will continue to draw attention for the preparation of novel intelligent materials. 

Tunca et al. [27, 28,38] reported in a series of papers on a multi-click approach for the preparation of brush copolymers. The backbone consisted of homopolymers, statistical polymers, or block copolymers from ONBEs with orthogonal side groups for Diels-Alder click reaction [27,28,38], azide/alkyne click reaction, [27, 28, 38] and nitroxide coupling [27]. In a grafting-to approach, maleimide-or ONBE-functionalized polymers (PEG, P BA, PMMA (56)) were attached by Diels-Alder click reaction with the anthracene groups pendant at the polymer backbone (55) (Scheme 9.8b). PCL chains were attached by an azide/alkyne click reaction, while a combination of Diels-Alder and azide/alkyne click reaction allowed the synthesis of graft copolymers with PS-/ -PEG-, PS-h-PMMA-, or PS-/ -P BA side chains. 

A simple, efficient multicomponent sequence was recently developed to synthesize a-hydroxyalkylpiperidine derivatives from a 4-boronohydrazonodiene, maleimides and aldehydes (Scheme 9.36) [78]. The high diastereoselectivity of these tandem reactions can be explained by a complete endo-selectivity in the first step and a cyclic chair-like transition state in the allylboration reaction. The absolute stereochemistry of the final products can be controlled by using an optically pure l-aza-4-borono-l,3 butadiene. This multi-component reaction can also be realized on a solid support, using an N-arylmaleidobenzoic acid functionalized resin. Very recently, this process... 

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