First Palladium-catalyzed Denitrative Coupling Reaction Of Nitroarenes With Phenols And Tetrabutylammonium Bromide-mediated Benzylation Of Phenols In Water Under Mild Condition

The first palladium-catalyzed protocol for the denitrated coupling reaction ofnitroarenes with phenols has been developed, achieving unsymmetrical diaryl ethersin moderate to excellent yields. The cyclopalladated ferrocenylimine (catalyst Ic)exhibited highly catalytic activity for this transformation with low catalyst loading(0.75mol%) and short reaction time (2h). The efficiency of this reaction wasdemonstrated by its compatibility with a range of groups. Moreover, the rigorousexclusion of air or moisture was not required in these transformations. Benzylation of phenol was successfully achieved in water under roomtemperature mediated by tetrabutylammonium bromide (TBAB) for only two hoursaffording the corresponding benzyl phenyl ether with good to excellent yields. Thisprotocol is very efficient, simple, avoiding catalysts, easy to work-up after a reactionand especially “green”.