Synthesis and application of cyclic polymers by using dynamic covalent bonds

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14272
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35010:Polymer chemistry-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Aoki Daisuke 東京工業大学, 物質理工学院, 助教 (80736950)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 環状分子 / 環状高分子 / 動的共有結合 / ジスルフィド / ポリエチレンオキシド

Outline of Final Research Achievements

A simple and efficient method to macrocyclic structures has been developed based on the dynamic behavior of the linker bis(2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS). The prime linear structure was transformed into a (macro)cycle using the following sequence: (i) thiol-ene reaction with a BiTEMPS derivative to afford the linear precursor, followed by (ii) an entropy-driven transformation induced by diluting and heating. The radicals generated from BiTEMPS upon heating are highly tolerant toward a variety of chemical species, including oxygen and olefins, while they exhibit high reactivity toward exchange reactions, which can be applied to the topology transformation of various skeletons. The specific advantages of the present method, i.e., its procedural simplicity and substrate versatility, are demonstrated by the gram-scale synthesis of cyclic compounds with low and relatively high molecular weight.

Free Research Field

高分子化学

Academic Significance and Societal Importance of the Research Achievements

環状化合物、特に分子量が中程度からそれ以上の環状高分子は、古くから他の形状の化合物や高分子とは異なる特異な機能・特性を発現することが知られていた。しかし、一方で環状という特異な形状は、その合成を困難にしていた。今回、開発した手法は酸素ケアや触媒が要らず、簡便な操作で行うことができることから、幅広い分野での工業的な利用はもちろん、学術的にも環状骨格の詳細な機能・特性についてより詳細な解析が期待できる。また狙った分子骨格に環状分子特有の分子認識能や包接能といった特異の機能・物性を付与することもできる。この研究を契機に、環状分子を機能材料開発のツールとする新しい材料設計の指針を立てることができる。