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Cross-coupling reactions are important for the production of pharmaceuticals, [4] examples being montelukast, eletriptan, naproxen, varenicline, and resveratrol. [21] with Suzuki coupling being most widely used. [22] Some polymers and monomers are also prepared in this way. [23]
The most common type of coupling reaction is the cross coupling reaction. [1] [2] [3] Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki were awarded the 2010 Nobel Prize in Chemistry for developing palladium-catalyzed cross coupling reactions. [4] [5] Broadly speaking, two types of coupling reactions are recognized:
Carbon is one of the few elements that can form long chains of its own atoms, a property called catenation.This coupled with the strength of the carbon–carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements of life, so carbon compounds have their own field of study: organic chemistry.
Some of the cross-coupling reactions that include a transmetalation step are Stille cross-coupling, Suzuki cross-coupling, Sonogashira cross-coupling, and Negishi cross-coupling. The most useful cross-coupling catalysts tend to be ones that contain palladium. Cross-coupling reactions have the general form of R′–X + M–R → R′–R + M ...
The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds (C-C bonds). This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo - and regioselectivity . [ 1 ]
In organic chemistry, the Kumada coupling is a type of cross coupling reaction, useful for generating carbon–carbon bonds by the reaction of a Grignard reagent and an organic halide. The procedure uses transition metal catalysts , typically nickel or palladium, to couple a combination of two alkyl , aryl or vinyl groups .
Building blocks that make up the network of CMPs must contain an aromatic system and have at least two reactive groups. To generate the porous structure of CMPs, cross-coupling of building blocks with different geometries to create a 3-D polymer backbone is necessary, while self-condensation reactions occur in the homo-coupling of building blocks with similar geometry. [2]
An effective heterogeneous cross-coupling catalyst will recapture monomeric Pd or lower order oligomers and colloids onto the solid phase in order to maintain low concentrations of these species in solution, disfavouring aggregation and favouring instead the productive elementary steps of cross-coupling. [4]