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]
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]
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]
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]
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 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]
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]
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]
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]
1st Generation Grubbs Catalyst1 (Ph = phenyl; PCy3 = tricyclohexylphosphine) - CAS#: [172222-30-9] - FW: 822.95 - Color: Purple - Initiation temperature: >20 °C Process Strengths Weaknesses CM2 -Synthesis of 1,2-disubstituted … [Continue reading]
At over a million tons of capacity, the Shell Higher Olefins Process (SHOP) is one of the standards of industrial olefin metathesis chemistry. SHOP is remarkable in both its chemistry and process engineering. The process was developed for the … [Continue reading]