Aryl derivatives arylphosphines

In a related strategy, ethynylphosphines (81) have been prepared with a view to synthesising polyphosphacyclopolyyne materials such as (82) (Scheme 24) [70]. Interaction between the phosphorus lone pairs and the organic 71-systems is supported by the fact that the phosphorus atoms of mono- and di-silyl-capped analogues of bis(arylphosphine) derivative (81) exhibit an unusually low inversion barrier (65 kj mol versus 130-140 kj mol for classical alkyl-or aryl-phosphines). Indeed, the rings (82) exhibit values of at ca. 300 nm, consistent with this assumption. 

A general and efficient method for the microwave-assisted synthesis of mono- and diarylphosphinic acids (579) and (581) from anihnium 7f-phosphinate (580) and aryl halides, using Pd(0) and Xantphos as a supporting ligand, has been developed by Stawihski and Kalek (Scheme A2)P The procedure was highly efficient and provided a rapid access to a broad spectrum of arylphosphinate derivatives. 

In addition to the examples described previously, a tremendous variety of compounds have been prepared using palladium-catalyzed cross-coupling reactions due to the broad functional group tolerance. The combination of copper and palladium complexes have been used to promote the formation of borane-protected arylphosphines [298]. Palladium acetate catalyzed the coupling of halogenated benzoic acid derivatives leading to the formation of water-soluble phosphine ligands [299]. Aryl triflates have also been used in the phosphination reaction [300]. Functionalized tyrosine derivatives were converted... 

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