Chiral phosphorus compounds play important roles in asymmetric catalysis. One of the applicable strategies for construction of these molecules is the desymmetrization of prochiral phosphorus compounds. Herein, we report a chiral thulium(III) catalyzed sulfur-conjugation addition reaction of dialkynylphosphine oxides to construct P-stereogenic centers. Dialkynylphosphine oxides bearing aryl, alkyl, alkenyl substitution at the alkyne terminus position were tolerated under the reaction conditions. The corresponding P,S-containing compounds were obtained in moderate to good yields (up to 92% yield) with excellent Z/E ratios and enantioselectivities (up to &gt;95/5 Z/E and 97% ee), which could be transformed into versatile optically active phosphine oxides derivatives. X-ray single crystal structures of chiral N,N'-dioxides with rare-earth metal triflates revealed how the center metal and ligand structure affect the enantioselectivity. A plausible transition state was proposed to explain the origin of the asymmetric induction.

Asymmetric synthesis of P-stereogenic compounds via thulium (III)-catalyzed desymmetrization of dialkynylphosphine oxides

2019 Fall National Meeting

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