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A general and convenient two-step synthetic method has been developed for the preparation of a novel class of aminoalkyl-phosphine type compounds, which involves nucleophilic ring-opening of cyclic sulfate esters. The ring-opening step was performed using several different aliphatic and aromatic amines to produce aminoalkyl sulfates that were reacted with LiPPh 2 to give the corresponding P,N-ligands. The desymmetrization procedure affords an easy route to synthesize enantiomerically pure pentane-2,4-diyl based P,N-ligands with a highly tunable structure. The ligands derived from primary amines have a stereogenic N-atom that can be useful in asymmetric catalytic syntheses.

A novel chiral ligand is synthesized and successfully applied in the Rh-catalyzed asymmetric hydrogenation of acetamides (I) and dimethyl itaconate (III).

Rhodium complexes derived from axially chiral ligands (I) are efficient catalysts in the asymmetric hydrogenation reactions of dehydroamino acid esters (II) and itaconate (IV), in the latter case even at only 0.01 mol% catalyst loading.