Quinidine-catalyzed enantioselective domino Michael addition/cyclization process: Synthesis of chiral 1,4-dihydro-pyridine containing benzosultams

Abstract

Domino catalytic reactions are a powerful methodology for the synthesis of complex and high-value compounds, which have remarkable advantages. Benzosultam, especially for chiral benzosultam, widely exists in bioactive molecules and drugs. Herein, we developed a domino enantioselective Michael addition/cyclization process catalyzed with quinidine, which is a cheap and readily available catalyst. The reaction was accomplished smoothly under mild conditions at room temperature within 2 h. A series of chiral 1,4-dihydro-pyridine containing benzosultams were prepared in good yields (up to 95%) and excellent enantioselectivities (up to 99% ee) vis this developed domino process.