Asymmetric Addition of 3-Thienyl Aluminum to Ketones Catalyzed by the Simple Titanium Catalytic System of (S)-1,1′-Binaphthol

The optically active diaryl alcohols bearing thienyl group are well-known for their biological activity as well as key substructure in bioactive compounds and pharmaceuticals. The asymmetric addition of 3-thienylaluminum to ketones afforded the optically active 3-thienyl arylethanols in good yields with high enantioselectivities of up to 910% ee employing the simple titanium catalytic system of (S)-1, 1'-binaphthol. The catalytic system could also suit for various ketones bearing an electron-donating or electron-withdrawing groups to afford the corresponding diarylethanols containing substituted 3-thienyl groups.