Organotungsten Compounds Catalysts in ROMP and ADMET

As already pointed out in Chapter 4, the number of synthesized metallo-organic tungsten compounds is immense and the reason why so many compounds have been 

A large number of tungsten organometallic compounds plays an important role, or can be regarded as prominent candidates, as catalyst in organic syntheses. Tungsten as well as molybdenum and rhenium catalysts are closely associated with metathesis polymerization. 

The term alkene metathesis describes a reaction mechanism shown schematically in he following equation  

The alkylidene groups of an alkene pair are exchanged with one another in the presence of a transition metal catalyst. In recent times, not only reactions between two C=C double bonds but also between C=C and C=0 bonds have been investigated. The reaction includes the cleavage of double C=C bonds and the formation of new ones. Homogeneous as well as heterogeneous catalysts are effective. 

One of the most important reaction mechanisms in organic polymer chemistry that can be catalyzed by tungsten compounds is Ring Open Metathesis Polymerization — ROMP. It can be expressed by the overall equation  

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