Arylphosphonate cross-coupling

The palladium-catalysed cross-coupling of aryl halides or vinyl halides with dialkyl phosphonates (31) to yield dialkyl arylphosphonates and dialkyl vinylphosphonates, respectively, was first reported by Hirao and co-workers 69 the halides used most frequently are bromides and the reaction is stereospecific with haloalkenes. Subsequently, analogous reactions of alkyl alkylphosphinates (32), alkyl arylphosphinates (32), alkyl phosphinates (33), and secondary phosphine oxides (34), replacing [P—H] bonds with [P—C] bonds to yield various phosphinates and tertiary phosphine oxides, have been developed (Figure 7.1). Alkyl phosphinates (33) may be mono- or diarylated as desired by the selection of appropriate conditions. Aiyl and vinyl triflates have also found limited... 

For insoluble development in Heck-type reactions is P-C and N-C bond formation, which results from coupling of aryl halides with phosphorous compounds [38] and amines [39]. The first application in aqueous medium was achieved by coupling of a dialkyl phosphite with an aromatic iodide to give an arylphosphonate in 99% yield. In 1996, Stelzer and co-workers presented a P-C cross-coupling reaction between primary and secondary phosphines and functional aryl iodides to water-soluble phosphines [Eq. (9)], which are potentially applicable as ligands in aqueous-phase catalysis [40]. 

A significant breakthrough in the synthesis of arylphosphonates was developed by Hirao (Scheme 4.221) [368, 369]. He developed a palladium-catalyzed cross-coupling... 

The use of arenediazonium tetrafluoroborates as substrates for palladium-catalyzed cross-coupling reactions generates arylphosphonates in moderate to excellent yields (Schemes 4.238 and 4.239) [292]. While most palladium-catalyzed C—P bond-forming reactions use secondary phosphites as substrates, this approach uses trialkylphosphites. The chemistry displayed excellent functional group compatibility as arenes bearing esters. 

SCHEME 4.244 Synthesis of arylphosphonates through nickel-catalyzed cross-coupling [341],... 

SCHEME 4739. Synthesis of dinucleoside arylphosphonates via stereospecific C—P bond-forming cross-coupling. 

Kalek M, Jezowska M, Stawinski J. Preparation of arylphosphonates by palladium(0)-catalyzed cross-coupling in the presence of acetate additives synthetic and mechanistic studies. Adv. Synth. Catal. 2009 351 3207-3216. 

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