Programmed folding into spiro-multicyclic polymer topologies from linear and star-shaped chains

Yoshinobu Mato,Kohei Honda,Brian J Ree,Tetsuo Deguchi,Toshifumi Satoh,Takuya Yamamoto,Takuya Isono,Kenji Tajima

doi:10.1038/s42004-020-00355-4

Yoshinobu Mato, Kohei Honda + Show 6 more

Open Access

https://doi.org/10.1038/s42004-020-00355-4

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Abstract

The development of precise folding techniques for synthetic polymer chains that replicate the unique structures and functions of biopolymers has long been a key challenge. In particular, spiro-type (i.e., 8-, trefoil-, and quatrefoil-shaped) polymer topologies remain challenging due to their inherent structural complexity. Herein, we establish a folding strategy to produce spiro-type multicyclic polymers via intramolecular ring-opening metathesis oligomerization of the norbornenyl groups attached at predetermined positions along a synthetic polymer precursor. This strategy provides easy access to the desired spiro-type topological polymers with a controllable number of ring units and molecular weight while retaining narrow dispersity (Ɖ < 1.1). This effective strategy marks an advancement in the development of functionalized materials composed of specific three-dimensional nanostructures.

Highlights

The development of precise folding techniques for synthetic polymer chains that replicate the unique structures and functions of biopolymers has long been a key challenge
Our group recently reported a robust and precise strategy for constructing a variety of cage-shaped multicyclic topologies based on intramolecular consecutive cyclization (i.e., intramolecular ring-opening metathesis oligomerization (ROMO) of an exonorbornenyl group attached to each terminus of star-shaped polymers), which enabled systematic synthesis and characterization[24]
To introduce the norbornenyl groups at the chain ends and the chain center, a diol initiator possessing a protected hydroxyl group was employed for the polymerization

Summary

Introduction

The development of precise folding techniques for synthetic polymer chains that replicate the unique structures and functions of biopolymers has long been a key challenge. A precise yet universal folding strategy to spiro-multicyclic polymers has remained elusive because increasing the number of constitutional cyclic units leads to synthetic difficulties.

Results

Conclusion