Related Experiment Video
Updated: Dec 3, 2025

A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes
Published on: February 27, 2017
Stereospecific Ring-Opening Metathesis Polymerization of Norbornene Catalyzed by Iron Complexes
Dmitry S Belov1, Logesh Mathivathanan1, Melanie J Beazley2
1Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St., Miami, FL, 33199, USA.
Abstract:
Developing well-defined iron-based catalysts for olefin metathesis would be a breakthrough achievement in the field not only to replace existing catalysts by inexpensive metals but also to attain a new reactivity taking advantage of the unique electronic structure of the base metals. Here, we present a two-coordinate homoleptic iron complex, Fe(HMTO)2 [HMTO=O-2,6-(2,4,6-Me3 C6 H2 )2 C6 H3 ], that is capable of performing ring-opening metathesis polymerization of norbornene to produce highly stereoregular polynorbornene (99 % cis, syndiotactic). The use of heteroleptic Fe(HMTO)(RO) [RO=(CH3 )2 CF3 CO, CH3 (CF3 )2 CO, or Ph(CF3 )2 CO] prepared in situ significantly increases the polymerization rate while preserving selectivity. The resulting polymers were characterized by 1 H and 13 C NMR spectroscopy and gel-permeation chromatography.
More Related Videos
Related Concept Videos
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Base-Catalyzed Ring-Opening of Epoxides
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Acid-Catalyzed Ring-Opening of Epoxides
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.

