Synthesis of P‐Stereogenic Phosphine Oxides via Nickel‐Catalyzed Asymmetric Cross‐Coupling of Secondary Phosphine Oxides with Alkenyl and Aryl Bromides
A nickel-catalyzed asymmetric C(sp2)−P cross-coupling for the synthesis of P-stereogenic phosphine oxides under mild conditions is reported. The enantioselective alkenylation/arylation of racemic secondary phosphine oxides with alkenyl/aryl bromides provided P-stereogenic phosphine oxides with high enantioselectivities of up to 99 % ee.
A new family of H-adamantylphosphinates as universal precursors of P-stereogenic ligands was obtained in one step from commercial chlorophosphines. Both enantiomers of these air- and moisture-stable intermediates can easily be separated by semipreparative chiral HPLC on a gram scale and individually undergo stereoselective transformations to afford each enantiomer of a set of P-stereogenic compounds such as secondary phosphine oxides and boron-protected monophosphines.