Enantioselective and aerobic oxidative coupling of 2-naphthol derivatives using chiral dinuclear vanadium(V) complex in water

The enantioselective oxidative coupling of 2-naphthols in water was established using dinuclear vanadium(V/IV) catalysis with O2 as the sole co-oxidant. In the vanadium-catalyzed reaction, the corresponding coupling products were obtained in good to excellent yields with up to 94% enantiomeric excess. In water, racemization of the coupling product was suppressed even at high temperature (70 °C).

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(S)-7,7′-Bis((2-methoxyethoxy)methoxy)-1,1′-bi-2-naphtholC28H30O8Ee = 63% by HPLC on Daicel Chiralpak AS-H column[α]D22 = +61.9 (c 0.7, CHCl3)Source of chirality: Enantioselective oxidative couplingAbsolute configuration: (S)