writer：Yu, Z.; Wang, M.; Chen, X.; Huang, S.; Yang, H.*
keywords：Ring-Opening Metathesis Polymerization
source：期刊
specific source：Angewandte Chemie International Edition, 2022, 61, e202112526.
Issue time：2022年

Ring-opening metathesis polymerization (ROMP)

has been regarded as a powerful tool for sequence-controlled

polymerization. However, the traditional entropy-driven

ROMP of macrocyclic olefins suffers from the lack of ring

strain and poor regioselectivity, whereas the relay-ring-closing

metathesis polymerization inevitably brings some unnecessary

auxiliary structure into each monomeric unit. We developed

a macrobicyclic olefin system bearing a sacrificial silyloxide

bridge on the a,b’-positions of the double bond as a new class

of sequence-defined monomer for regioselective ROMP. The

monomeric sequence information is implanted in the macroring,

while the small ring, a 3-substituted cyclooctene structure

with substantial ring tension, can provide not only narrow

polydispersity, but also high regio-/stereospecificity. Besides,

the silyloxide bridge can be sacrificially cleaved by desilylation

and deoxygenation reactions to provide clean-structured, nonauxiliaried

polymers.