Transmetalation

Overview
Transmetalation (alt. spelling: transmetallation) is a general chemical reaction type in organometallic chemistry describing the exchange of ligands between two metal centers.



The metal centers need not be the same. The ligands R and R' can be organic or inorganic. The double displacement reaction is conceptually related.

Transmetalation is important in the synthesis of various organometallic compounds. Silver N-heterocyclic carbene complexes are easily formed, and are often used to transfer the carbene ligands to other metals containing labile ligands such as acetonitrile or 1,5-cyclooctadiene. Where L-H+ denotes the ligand precursor:


 * 2 L-H+ + Ag2O &rarr; L2Ag+...AgX- (X = ligand precursor counteranion)


 * L-Ag...AgX + PdCl2MeCN2 &rarr; PdL2Cl2

This reaction type also appears frequently in the catalytic cycle of various metal catalysed organic reactions such as the Stille reaction and the Negishi coupling.