(Angew. Chem. Int. Ed.) Ring-Opening Metathesis Polymerization of a Macrobicyclic Olefin bearing a Sacrificial Silyloxide Bridge
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.