Xantphos ligands, electronic effects

The use of Xantphos (9), first reported by Van Leeuwen [57], as supporting ligand allows for the efficient coupling of alkylarylamines and aryl bromides [58]. For example, the reaction of 4-bromobenzonitrile and N-ethylaniline proceeds in 85 % isolated yield, Eq. (29). This Hgand is particularly effective in the coupling of electron-deficient alkylarylamines and electron-deficient aryl bromides. 

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