Cross-Coupling Reactions

A cross-coupling reaction is an organic chemistry term for the joining of two fragments with the help of a metal catalyst. In one significant kind of reaction, an organic halide of type R'-X combines with a main group organometallic compound of type R-M (R = organic fragment, M = main group centre), resulting in the creation of a new carbon-carbon bond in the product R-R'. Coupling reactions include cross-coupling reactions as a subset. It frequently appears in arylations. The creation of palladium-catalyzed coupling processes earned Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki the 2010 Nobel Prize in Chemistry. In most cases, the process entails the reductive removal of the organic substituents R and R' on a metal complex of the form LnMR(R') (where L is some arbitrary spectator ligand). A low valence precursor Ln is used to create the key intermediate LnMR(R') in a two stage procedure. LnM is transformed into LnMR by the oxidative addition of an organic halide (RX) (X). Following transmetallation with a source of R', the second partner is subjected to. In order to renew the catalyst and produce the organic product, the two coupling fragments must be eliminated reductively in the last phase. Unsaturated substrates, including C(sp)X and C(sp2)X bonds, pair more quickly, in part because they add to the catalyst more readily.