Controllable ROMP Tacticity by Harnessing the Fluxionality of Stereogenic-at-Ruthenium Complexes

• Published in: Angewandte Chemie International Edition Vol. 55; no. 16; pp. 4997 - 5002
• Main Authors: Mikus, Malte S., Torker, Sebastian, Hoveyda, Amir H.
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 11-04-2016; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: catalysis; olefin metathesis; polytopal rearrangement; ring-opening metathesis polymerization (ROMP); stereochemistry; olefin metathesis; stereochemistry; ring-opening metathesis polymerization (ROMP); catalysis; polytopal rearrangement
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201601004

Readily accessible and easy‐to‐handle Ru complexes capable of generating all‐Z polynorbornene and polynorbornadiene by ring‐opening metathesis polymerization (ROMP) with controllable selectivity, ranging from ≈50 to ≥95 % syndiotactic, are introduced. It is demonstrated that the rate of non‐metathesis based polytopal isomerization and levels of syndiotacticity may be fine‐tuned by the adjustment of monomer concentration and catalyst's steric and electronic characteristics.
Flexible but controllable: By adjustment of monomer concentration and alteration of steric and electronic attributes of Z‐selective Ru catechothiolate complexes, the competing polytopal isomerization and product tacticity in ROMP reactions can be controlled. Reactions are easy to perform (unpurified monomer, no glove box), and the tacticty range can be fine‐tuned.