Trifluoromethylated chiral quaternary stereogenic carbon center at 2-position of thiochromans has been constructed through organocatalyzed Michael-aldol reaction. With quinine squaramide as catalyst, the reaction of 2-mercaptobenzaldehyde with β-aryl-β-CF3 enones or β-alkyl-β-CF3 enones gave 2-CF3-thiochromans bearing three contiguous stereogenic centers in good to excellent diastereoselectivities, enantioselectivities, and yields.
Key words
cascade reaction - asymmetric catalysis - orgnocatalytic - CF
3-containing - sulfur-containing heterocycle