Dialkyl arylphosphonates synthesis

This method is also suitable for the synthesis of steric-hindered dialkyl arylphosphonates. The yields of dialkyl arylphosphonates are, however, lower than in the case where cupric iodide is used as a catalyst. 

Arbuzov and Michaelis-Becker reactions provide facile and versatile procedures for the formation of carbon-phosphorus bonds. These methods, however, are not applicable to the formation of sp hybridized carbon-phosphorus bonds. Only few methods have been reported for the syntheses of arylphosphonates and vinylphospho-nates. Direct reaction of aryl or vinyl halides with trialkyl phosphite in the presence of nickel halide requires severe reaction conditions [21,22], and the stereochemistry of vinylphosphonates has not been clarified. Synthesis of dialkyl arylphosphonates 22 [23, 24] is achieved by the palladium-catalyzed reaction (Scheme 2.12), which is called by Hirao reaction . The stereoselective synthesis of dialkyl vinylphosphonates 23 [24-26] is similarly accomplished by this method (Scheme 2.13). A variety of modified procedures have been developed recently [27-37]. 

---