A “green” variation of the Hirao reaction: the P–C coupling of diethyl phosphite, alkyl phenyl-<i>H</i>-phosphinates and secondary phosphine oxides with bromoarenes using a P-ligand-free Pd(OAc)<sub>2</sub> catalyst under microwave and solvent-free conditions
作者:György Keglevich、Erzsébet Jablonkai、László B. Balázs
DOI:10.1039/c4ra03292f
日期:——
The P–C coupling of diethyl phosphite, alkyl phenyl-H-phosphinates, diphenylphosphine oxide and dialkylphosphine oxides with bromoarenes may be performed in the presence of a P-ligand-free Pd(OAc)2 catalyst and triethylamine undermicrowave-assisted (MW) and, in almost all cases, solvent-free conditions to afford diethyl arylphosphonates, alkyl diphenylphosphinates, aryldiphenylphosphine oxides and
NiCl2-catalyzed P–C coupling reaction of arylhalides and various > P(O)H-compounds under MW conditions without directly added P-ligands. The reactivity of a few aryl derivatives in the Pd(OAc)2-catalyzed Hirao reaction was also studied. An induction period was observed in the reaction of bromobenzene and diphenylphosphine oxide. Finally, the less known copper(I)-promoted P–C coupling reactions were investigated