Practical synthesis of chiral vinylphosphine oxides by direct nucleophilic substitution. Stereodivergent synthesis of aminophosphine ligands

A practical synthesis of optically pure alkylphenylvinylphosphine oxides is described, utilizing a nucleophilic displacement at phosphorus to install the vinyl moiety. The products were used to prepare classes of P-stereogenic aminophosphine (PN) and aminohydroxyphosphine (PNO) ligands. Stereocontrol can be exerted at various stages of the synthesis, to provide specific combinations of chirality in the final product. The effect of the stereogenic phosphorus and match-mismatch of chiralities of PNO ligands were examined in the asymmetric ruthenium-catalyzed hydrogen transfer reduction of three aryl ketones.