Catalytic asymmetric conjugate addition of mercaptans to β-substituted-β-trifluoromethyl oxazolidinone enoates : access to chiral trifluoromethylated tertiary thioethers and thiols

• Main Authors: Chen, Wenchao, Jing, Zhengzhong, Chin, Kek Foo, Qiao, Baokun, Zhao, Yan, Yan, Lin, Tan, Choon-Hong, Jiang, Zhiyong
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis
• Online Access: https://hdl.handle.net/10356/101214; http://hdl.handle.net/10220/19802
• Institution: Nanyang Technological University

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.