Synthesis of Benzene Derivatives with Multiple Dichlorophosphino Groups.

The chlorination of 1,2-diphosphinobenzene with PCl5 to 1,2-bis(dichlorophosphino)benzene was performed with high yields (93 %) despite the high number of P-H functions. The method was further applied to other phosphanes, enabling the first synthesis and complete characterization of 1,2,4-tris(dichlorophosphino)benzene (89 % yield) and 1,2,4,5-tetrakis(dichlorophosphino)benzene (91 % yield), valuable precursors for example for binuclear complexes, coordination polymers, organic wires, or metal-organic frameworks. The application of the chlorophosphanes in base induced ring closure reactions with primary amines is demonstrated.