: Access to Chiral Trifluoromethylated Tertiary Thioethers and Thiols,
Wenchao Chen, Zhengzhong Jing, Kek Foo Chin, Baokun Qiao, Yan Zhao, Lin Yan, Choon‐Hong Tan and Zhiyong Jiang
Advanced Synthesis and Catalysis, 2014, 356, 1292 – 1300
Abstract: The first asymmetric conjugate addition of mercaptans to β‐substituted‐β‐trifluoromethyl oxazolidinone enoates has been developed. The opposite enantiomers of adducts, containing a trifluoromethylated hetero‐quaternary stereogenic centers, could be obtained by utilizing two pseudo‐enantiomeric Cinchona alkaloid‐derived tertiary amine/squaramides as catalysts. Potassium dihydrogen phosphate was found to accelerate the reaction rate without compromising the enantioselective excess. A variety of chiral trifluoromethylated tertiary thioethers and thiols were readily prepared with excellent enantioselectivity.
Paper download: https://doi.org/10.1002/adsc.201301027