Metal-Free Multicomponent Tandem Polymerizations of Alkynes, Amines, and Formaldehyde toward Structure- and Sequence-Controlled Luminescent Polyheterocycles

Abstract

Sequence-controlled polymers, including biopolymers such as DNA, RNA, and proteins, have attracted much attention recently because of their sequence-dependent functionalities. The development of an efficient synthetic approach for non-natural sequence-controlled polymers is hence of great importance. Multicomponent polymerizations (MCPs) as a powerful and popular synthetic approach for functional polymers with great structural diversity have been demonstrated to be a promising tool for the synthesis of sequence-controlled polymers. In this work, we developed a facile metal-free one-pot multicomponent tandem polymerization (MCTP) of activated internal alkynes, aromatic diamines, and formaldehyde to successfully synthesize structural-regulated and sequence-controlled polyheterocycles with high molecular weights (up to 69 800 g/mol) in high yields (up to 99%). Through such MCTP, polymers with the in situ generated multisubstituted tetrahydropyrimidines or dihydropyrrolones in the backbone and inherent luminescence can be easily obtained with high atom economy and environmental benefit, which is inaccessible by other synthetic approaches.

The Marriage of Aggregation‐Induced Emission with Polymer Science

“…This polymerization exhibits the advantages of high efficiency, good atom economy, simple operation, inexpensive monomers, and high oxygen and moisture tolerance, thus meeting the requirements of “green chemistry”. Besides the MCP of alkyne, sulfonyl azide, and nucleophiles, AIE polymers with different structures and functionalities can also be generated by other MCPs such as (1) alkyne, carbonyl chloride, and nucleophiles; (2) Kabachnik–Fields reaction; and (3) alkyne, aldehyde, and amine …”

Copper‐Free Synthesis of Glycidyl Triazolyl Polymers

“…The electron‐deficient alkynes 4 , 5 , and 6 were synthesized by transesterification from the alkynes 1 and 2 . We improved the synthetic method reported by other groups . TsOH was applied as an acid catalyst.…”

Multicomponent Tandem Polymerization of Aromatic Alkynes, Carbonyl Chloride, and Fischer's Base toward Poly(diene merocyanine)s

“…To explore the general applicability of MCPs and their polymerization product structures, a popular tandem strategy in organic synthesis has been introduced to MCPs . The multicomponent tandem polymerizations (MCTPs) were developed to synthesize heteroatom or heterocycles‐containing conjugated polymers or sequence‐controlled polymers with well‐defined structures in one pot . For example, sulfur‐rich conjugated polymers with good stereoselectivity was prepared through the MCTP of alkynes, carbonyl chlorides, and thiols; conjugated polypyrazoles were prepared from the MCTP of alkyne, carbonyl chlorides, and benzohydrazines; polypyrimidines could be obtained from the coupling‐addition‐cyclization‐oxidation four‐step MCTP of alkyne, guanidine hydrochloride, DMSO, and O 2 ; most recently, poly(indolone)s with acid‐triggered fluorescence response property were synthesized through MCTP .…”