Monophosphine ligands aryl halide oxidative additions

The similar reaction of diarylphosphine oxides with aryl halides and triflates has been used more recently to prepare a variety of ligands for asymmetric catalysis. Many of these reactions involve additions of secondary phosphine oxides to di- or monotriflates derived from binaphthol because the triflates are more accessible than 2,2 -l,l -dibro-mobinaphthol. Workers at Syntex described a procedure to use the ditriflate of binaphthol to prepare mixed phosphine oxide, hydroxo ligands, and the monophosphine oxide, bi-naphthyldiphenylphosphine oxide. Hayashi then developed a route to a number of chiral monodentate phosphine ligands with a 2-(diphenylphosphino)-2 -alkoxy-l,l -binaphthyl structure (Eq. Reaction of the ditriflate with diphenylphosphine oxide in the... 

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