Copper Promoted C-N and C-O Type Cross-Coupling Reactions

Aryl amines and ethers are very important structural motifs of numerous biologically active natural products, important pharmaceutical compounds, polymers in the material science industries and widely used as drugs, dyes, and other fine chemicals. Several studies have earlier been attempted but transition metal mediated protocols have proven more successful results. Conventional Ullmann condensation with copper in the form of metal, alloy or Cu(I)/Cu(II) salt showed major drawbacks such as requirement of high temperature sensitivity to catalyst-type and low to moderate yield. In recent years, copper promoted conventional Ullmann condensation reactions have been improved a lot under ligand and ligand free conditions with excellent conversion. An important Ullmann type coupling, where aryl boronic acids are used as arylating agents instead of aryl halides has recently attracted much attention of chemist. Because of the importance of aryl amines and ethers in various fields of chemistry writing a review in this relevant area is of significant interest. This article will review the applications of copper-promoted C-N and C-O bond formation reactions focused on achievements during the periods from 2000-2008.