Catalyst‐Free Multicomponent Cyclopolymerizations of Diisocyanides, Activated Alkynes, and 1,4‐Dibromo‐2,3‐Butanedione: a Facile Strategy toward Functional Polyiminofurans Containing Bromomethyl Groups

Abstract

Polymers containing iminofuran (PIFs) are rarely reported due to the lack of simple and effective synthesis methods. In this work, a novel multicomponent cyclopolymerization (MCCP) of diisocyanides, activated alkynes, and 1,4‐dibromo‐2,3‐butanedione using catalyst‐free one‐pot reactions under mild conditions to prepare PIFs containing bromomethyl groups is reported. PIFs with good solubility and thermal stability are obtained with high Mws (up to 19 600) and good yields (up to 89.5%) under optimized polymerization conditions. The structure of the PIFs is characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. The photophysical properties indicate that polymers P1a2b3 and P1c2b3 have cluster‐triggered emission characteristics. Thin films made from PIFs quickly degrade under UV irradiation. Moreover, the obtained polymers are decorated with bromomethyl and carboxylate groups in the side chain, which can be postfunctionalized to prepare multifunctional materials, such as star branched polymers and biomedical carrier materials. Thus, this work not only enriches the field of polymerization based on isocyanates and activated alkynes but also provides a facile strategy toward functional iminofuran polymers.

Multicomponent Spiropolymerization of Diisocyanides, Diethyl Acetylenedicarboxylate, and Halogenated Quinones

“…The results demonstrated that the bis-spiropolymers synthesized from nonaromatic monomers 1a and 1b showed emission peaks ranging from 500 to 550 nm, which should result from cluster-triggered emission characteristics caused by the ester groups according to our previous work. [44,55] The polymers P1c3a and P1c3b based on aromatic monomer 1c, however, www.advancedsciencenews.com www.mrc-journal.de showed no emission, which is attributed to the poor throughspace conjugation. [56,57]…”

“…Due to the bis-spirorings with halogen and UV-sensitive iminofuran rings in the obtained polymers, [44] the bis-spiropolymers could be used in the pesticide field by degradation. UV-vis absorption spectra were used to characterize the photodegradation process of P1a3c as an example under simulated sunlight at 380-780 nm (Figure S27, Supporting Information).…”

“…Recently, our group developed MCSPs for preparing functional spiropolymers using alkynes, diisocyanides, and the third monomer containing the C=O group via catalyst-free one-pot conditions. [39,40] In addition, functional heterocyclic polymers have been obtained from various third monomers containing the C=O group, such as polyfurans, polyiminofurans, and poly(iminofuranarylene)s. [41][42][43][44] Based on previous work, quinones containing two C=O groups attracted our interest. The compounds are often used for the preparation of functional polymers, such as electrodes, hydrogels, and fluorescent dyes.…”

In Situ Generation of Heterocyclic Polymers by Triple‐Bond Based Polymerizations

“…Dong's group has also made great contributions for the in-situ construction of five-membered heterocyclic polymers based on isonitriles. [37][38][39][40][41][42][43] For example, they reported a catalystfree cyclopolymerization of diisocyanide, dialkylacetylene dicarboxylates and dialdehyde in 2019 (Scheme 2C). [42] The reaction in situ generated poly(amine-furan-arylene)s with high molecular weights (M w up to 76 400 g mol −1 ) and good thermal stability under mild conditions.…”

“…Very recently, Dong's group further expanded the polymerization routes toward the furan-derivative polymers by a cyclopolymerization of diisocyanides, activated alkynes and 1,4-dibromo-2,3-butanedione (Scheme 2D). [43] This catalyst-free polymerization efficiently produced five-membered heterocyclic polymers containing post-functionalizable bromomethyl group. The M w of the polymeric products was up to 19 600 g mol −1 .…”