Olefin metathesis

Olefin metathesis
Ple210 · CC BY-SA 4.0 · source
Name	Olefin metathesis
Type	Catalytic carbon–carbon bond reorganization
Catalysts	Hermann Staudinger (historical polymer science), Richard R. Schrock (molybdenum catalysts), Robert H. Grubbs (ruthenium catalysts), Yves Chauvin (mechanistic work)
First reported	1950s–1960s

Olefin metathesis is a class of chemical reactions in which carbon–carbon double bonds are reorganized via the formal exchange of alkylidene fragments between alkenes. The transformation, developed through work by Hermann Staudinger, Yves Chauvin, Richard R. Schrock, and Robert H. Grubbs, underpins advances in synthetic methods used by practitioners associated with University of California, Berkeley, Massachusetts Institute of Technology, Caltech, BASF, and DuPont. Olefin metathesis links innovations from laboratories such as ETH Zurich, Imperial College London, and Scripps Research to commercial plants at companies like Evonik Industries and Dow Chemical Company.

History

Early observations of C=C bond redistribution emerged in studies at Goodyear Tire and Rubber Company, Phillips Petroleum Company, and Standard Oil during mid‑20th century investigations of polymerization and hydrocarbon cracking. Systematic mechanistic proposals were advanced by Yves Chauvin in the 1970s, with catalyst design breakthroughs reported by Richard R. Schrock at MIT and Robert H. Grubbs at Caltech in the 1990s, culminating in recognition by the Nobel Prize in Chemistry committee. Industrial uptake accelerated following process optimizations at BASF, Dow Chemical Company, and Monsanto, while academic refinements continued at institutions including Harvard University, Stanford University, and University of Wisconsin–Madison.

Mechanism and Catalysts

The widely accepted mechanism invokes a metallacyclobutane intermediate arising from a [2+2] cycloaddition between a metal alkylidene and an alkene, a model formalized by Yves Chauvin. Well‑defined catalysts include Schrock’s high‑oxidation‑state Richard R. Schrock molybdenum and tungsten complexes and Grubbs’ late‑transition‑metal ruthenium carbene complexes developed by Robert H. Grubbs. Catalyst classes trace research lineages to groups at ETH Zurich, Scripps Research, and Max Planck Society, and are tailored by ligand frameworks influenced by work at University of Cambridge, University of Oxford, and Princeton University. Heterogeneous analogs derive from surface organometallic chemistry advanced at CNRS and Institut Français du Pétrole research centers, with support from engineering efforts at University of Minnesota and Georgia Institute of Technology.

Types and Variants

Variants include ring‑closing metathesis (RCM) popularized in syntheses reported from Scripps Research and University of California, Los Angeles, cross metathesis (CM) applied by groups at ETH Zurich and Imperial College London, ring‑opening metathesis polymerization (ROMP) developed in work connected to Bell Labs and IBM Research, and acyclic diene metathesis polymerization (ADMET) exploited by teams at Dow Chemical Company and BASF. Related methodologies such as enyne metathesis feature in syntheses from Harvard University and Columbia University, while tandem and cascade metathesis sequences have been demonstrated in laboratories at Caltech and University of Cambridge.

Applications

Olefin metathesis enables key transformations in total syntheses reported by groups at Scripps Research, Harvard University, and University of California, Berkeley. Pharmaceutical routes optimized by Pfizer, Novartis, and Merck & Co. use metathesis steps for macrocyclization and fragment coupling. Polymer industries at BASF, Dow Chemical Company, and Evonik Industries employ ROMP and ADMET for specialty elastomers, while commodity chemical processes at ExxonMobil and Shell plc leverage metathesis for olefin upgrading. Fine chemical companies such as Lonza and DSM incorporate metathesis in flavor, fragrance, and agrochemical syntheses. Academic applications intersect with structural biology programs at Cold Spring Harbor Laboratory and materials research at Lawrence Berkeley National Laboratory.

Industrial and Commercial Processes

Commercialization emerged through collaborations among Caltech, Monsanto, and BASF, and process routes were scaled by Dow Chemical Company and Shell plc for large‑scale olefin interconversion. Licensed catalyst systems from Degussa (now Evonik Industries) and technology transfers involving DuPont and Chevron enabled deployment in petrochemical contexts. Process engineering developments at Aachen University and University of Manchester advanced continuous flow and reactor designs used by ExxonMobil and SABIC to integrate metathesis into refinery streams and monomer production lines.

Challenges and Developments

Ongoing challenges include catalyst stability under industrial feedstock conditions addressed by research at Max Planck Society and ETH Zurich, control of selectivity for E/Z isomers pursued at Caltech and Imperial College London, and removal of trace metal residues to meet regulatory standards enforced by Food and Drug Administration and European Medicines Agency. Emerging directions encompass photo‑ and electrocatalytic metathesis investigated at MIT and Stanford University, bioinspired approaches explored at University of Oxford, and sustainable feedstock integration championed by International Energy Agency initiatives and corporate R&D at Novozymes and Cargill.

Category:Organic reactions