Chemistry And The Chemical Industry

1767 WordsSep 13, 20158 Pages
Introduction A carbene is an organic compound comprised of a carbon atom with six valence electrons, four involved in bonding and a lone pair. A metal carbene however has its two electrons in the lone pair involved in a double bond to a transition metal; these carbenes can display nucleophilicity or electrophilicity behaviour depending on the characteristics of the metal it has combined with. Their relative stability in comparison to free carbenes makes them much more useful in organic synthesis; this increased stability allows chemists to be able to control the reaction and products a lot more reliably. Robert H. Grubbs is a key figure in chemistry, known for his Nobel prize winning work on the involvement of ruthenium catalysts in olefin metathesis reactions. This was an extremely important synthesis due to the popularity of olefin metathesis in the chemical industry. The efficiency of the catalyst in standard conditions was a great bonus or relatively small expense. The only real competitors to the Grubbs catalysts have are Schrock catalysts, which are examples of Schrock alkylidenes. Molybdenum and Tungsten based catalysts have the edge in the conversion of sterically demanding substrates, but generally have lower activity. A professor named Amir H. Hoveyda and his group managed to develop the Hoveyda-Grubbs first generation catalyst, which is another useful olefin metathesis catalyst, despite its increased cost and slower reactivity due to its increased stability over
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