Conrad, J. C.; Eelman, M. D.; Silva, J. A. D.; Monfette, S.; Parnas, H. H.; Snelgrove, J. L.; Fogg, D. E. Oligomers as Intermediates in Ring-Closing Metathesis. J. Am. Chem. Soc. 2007, 129, 1024-1025. Reading this communication changed the way I … [Continue reading]
2nd Generation Hoveyda Catalyst
2ndGeneration Hoveyda Catalyst1 - CAS#: [301224-40-8] - FW: 626.62 - Color: Green - Initiation temperature: >0 °C Process Strengths Weaknesses CM2 -Compatible with most olefins, including highly electron-deficient (i.e. … [Continue reading]
Grubbs Triblock Copolymers
Careful combination of multiple polymerization mechanisms can generate truly unique architectures. Incorporation of chain-segments generated by metathesis polymerizations have been explored by a number of researchers (particularly the Matyjaszewski … [Continue reading]
Identifying the Best Ruthenium Catalyst
Bieniek, M.; Michrowska, A.; Usanov, D. L.; Grela, K. In an Attempt to Provide a User’s Guide to the Galaxy of Benzylidene, Alkoxybenzylidene, and Indenylidene Ruthenium Olefin Metathesis Catalysts. Chem. Eur. J. 2008, 14, 806-818. There are a … [Continue reading]
Inhibiting Olefin Isomerization
Olefin isomerization/migration can be an annoying side reaction of olefin metathesis, in no small part because the side products are usually difficult to separate from the desired product. The isomerization is catalyzed by metal hydride species … [Continue reading]
Low Polydispersity ROMP Catalyst
Although their increased functional-group tolerance has made the ruthenium-based metathesis catalysts extremely attractive for use as polymerization catalysts, these catalysts have typically struggled to match the “living” polymerizations of the … [Continue reading]
ROMP Catalysts: Key Fundamentals
Buchmeiser M. R. Homogeneous Metathesis Polymerization by Well-Defined Group VI and Group VII Transition-Metal Alkylidenes: Fundamentals and Applications in the Preparation of Advanced Materials. Chem. Rev. 2000, 100, 1565. This 2000 review … [Continue reading]
2nd Generation Grubbs Catalyst
2nd Generation Grubbs Catalyst1 (Ph = phenyl; PCy3 = tricyclohexylphosphine) - CAS#: [246047-72-3] - FW: 848.97 - Color: Orange-brown - Initiation temperature: >10 °C. Process Strengths Weaknesses CM2 -Applies to most … [Continue reading]
Synthesis of Telechelics through Olefin Metathesis
The preparation of telechelic oligomers and polymers is of great interest for a number of fields, but it is typically quite difficult to generate compounds such that they are perfectly difunctional (fn = 2.0). However, olefin metathesis has proven to … [Continue reading]
Early Industrial Applications of Olefin Metathesis
Mol, J. C. Industrial Applications of Olefin Metathesis. J. Mol. Catal. A: Chem. 2004, 213, 39-45. Johannes Mol wrote a summary on the state of olefin metathesis in industrial processes in 2004. It’s got detailed descriptions of the early … [Continue reading]
Metathesis Catalyst Removal Techniques
Purification of a metathesis mixture can give you all sorts of problems (especially when using high catalyst loadings). Sometimes you need multiple columns to get a colorless product. Sometimes residual ruthenium can cause the product to isomerize … [Continue reading]