Multicomponent Cyclopolymerization Of Isocyanide Monomers

Studies on isocyanide-based reactions could date back to 1921,when the Passserini reaction was reported.However,most of these research efforts did not initially lead to progress in the preparation of isocyanide-based cyclopolymers.The main challenge is the lack of efficient polymerization reactions,which limit the large-scale preparation and application of these cyclopolymers.Modern organic chemistry provides an efficient way to develop efficient isocyanide-based cyclopolymers,however,the preparation of isocyanide-based cyclopolymers by reaction of isocyanide compounds remains extremely challenging.Through multicomponent cyclopolymerization reactions,diisocyanide monomers can participate in catalyst-free one-pot reactions to prepare naturally bioactive and biocompatible heterocyclic polymers,resulting in novel isocyanide-based cyclopolymers with biological functions.In this thesis,two new types of multicomponent cyclopolymerizations based on isocyanide monomers are established.First,a catalyst-free one-pot multicomponent cyclopolymerization of diisocyanide,diisocyanate and dialkylacetylene dicarboxylate(DAAD)monomers was developed,and heterocyclic polymers with high molecular weights(up to 29000),high light transmission and thermal stability were prepared in high yields(up to 85%).The cyclopolymerization has good monomer adaptability for both aliphatic and aromatic diisocyanide.Moreover,the heterocyclic polymers had high refractive indexes,which have great potential for optical instrument applications.The good solubility and processability of the polymers also provide a good basis for their subsequent application.In addition,these polymers have self-assembly behavior and remain stable under acidic environments.Subsequently,a highly efficient catalyst-free one-pot multicomponent cyclopolymerization was developed by changing the third monomer to isothiocyanate compounds.The cyclopolymerization reaction can be applied to aliphatic and aromatic diisothiocyanates,and a series of heterocyclic polymers with high molecular weights(M_w up to 21700)can be produced in high yields(up to 91%)after 9 hours of reaction at 100?.What's more,this cyclopolymerization is fast and efficient,and the polymers all have good thermal stability,with thermal weight loss temperatures as high as 290°C.More importantly,these polymers exhibit good solubility,excellent film formation and light transmission properties.In addition,the polymers show excellent antibacterial abilities especially for gram-positive bacteria such as staphylococcus aureus and therefore have some potential medical and pharmaceutical applications.