Enantioselective Squaramide-Catalyzed Trifluoromethylthiolation-Sulfur-Michael/Aldol Cascade Reaction: One-Pot Synthesis of CF3S-Containing Spiro Cyclopentanone-Thiochromanes.

A novel bifunctional squaramide-catalyzed one-pot electrophilic trifluoromethylthiolation-sulfur-Michael/aldol cascade reaction for the construction of CF3S-containing spiro-cyclopentanone-thiochromanes was developed. This convenient, one-pot cascade reaction serves as a powerful tool for the enantioselective construction of potential bioactive spiro-cyclopentanone-thiochromanes, which have one quaternary stereocenter containing a CF3S group and three contiguous stereocenters including one spiro all-carbon quaternary center, in moderate to good yields with excellent stereoselectivities (up to 15:1 dr, >99% ee). The synthetic transformations of the resulting products were also be achieved.