Fischer and Schrock Carbene Complexes: A Molecular Modeling Exercise #chempaperaday 246

Transition metal carbene complexes are really important complexes in organometallic chemistry and they are used to produce important organic molecules like the ones in olefin metathesis for example. Two of these complexes are much more important and in fact they both have names: Fischer and Schrock type carbenes. You can read about these in any inorganic chemistry textbook. But, I think you can never find a better summary of these complexes. This paper, although a molecular modeling exercise, does a great job explaining the general properties of these two type carbenes.  I wish textbooks were as clear and as simple as this article.

The metathesis reactions: from a historical perspective to recent developments #chempaperaday 201

A nice historical perspective of olefin metathesis and metathesis catalysts. The article was published in 2005. So, don't expect to see exciting new stuff like enantioselective ones.

I remember writing on metathesis before. So, let's add some new things that I learned.

"..the first observation of the metathesis of propene at high temperature was reported in 1931.

Schrock, then at Du Pont, tried to synthesize [Ta(CH2CMe3)5], which would not contain b-hydrogens and thus, according to this principle, should have been stable. Good luck smiles only on good scientists, and the expected compound did not form...led to the isolation of the first stable metal-alkylidene complex, [Ta(CH2CMe3)3(=CHCMe3)]."

A Salute to My Colleague Yves Chauvin, 1930–2015 #chempaperaday 196

Olefin metathesis is one of the most important and useful chemical transformations. The earliest versions of this reaction involved using not well defined catalysts and the reaction mechanism was not understood. In 1971, Chauvin proposed a mechanism that is accepted as the actual mechanism of the reaction today.

metathesis mechanism (source:wikipedia)

Chauvin died on January 27. I have read about him before. But, I think this is the best article.
Here are a few quotes from him proving how good a scientist he was:

“If you want to find something new, look for something new!”

“Some people say that there is too much chemistry in our society. It is in fact the opposite: there is not enough chemistry, not enough understanding, not enough control of chemical reactions. Catalysis is the key for a better chemistry.”