Ullmann-type coupling reactions

As seen in the retro-synthetic Scheme 5.3, intermediate 15 is useful for both routes. The choice of benzyl protection group was made based on the robust stability of benzyl phenol ethers toward most reactions and several possible avenues to remove it, although it was reported from Medicinal Chemistry that benzyl group removal via hydrogenolysis posed challenges in this compound. The choice of iodide substitution was born out of the known high reactivity of iodides in the Ullmann-type coupling reaction with alcohols and the robust stability of aryl iodides in many other common reactions. 

Copper-Catalyzed Ligand Promoted Ullmann-type Coupling Reactions... 

Figure 9.1 Some typical ligands used for Ullmann-type coupling reactions.

Wurtz- and Ullmann-type coupling reactions forming C-C bonds... 

Monnier F, Taillefer M (2009) Catalytic C-C, C-N, and C-O Ullmann-type coupling reactions. Angew Chem Int Ed 48(38) 6954-6971... 

Ullmann-type coupling reactions also offer the possibility to couple N-nucleophiles such as azide salts, hydroxylamines, nitrite salts, sulfonimidamides or phosphinic amides. 

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