Enantioselective N-H Insertion of Sulfonamides: Access to Chiral α-Aminoesters
Shaoran An1, Ruixi Zheng1, Ying Shao1
1Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
Abstract:
We report the first highly enantioselective carbene insertion into the N-H bonds of sulfonamides, affording α-amino esters in moderate to good yields with excellent enantioselectivity (up to 98% ee). The success of this transformation relies on the synergistic effect between a ruthenium carbene intermediate and a chiral phosphoric acid. Slight modification of the reaction conditions further enables the use of carbamates as N-nucleophiles, achieving exceptional enantiocontrol (up to 99% ee). Additionally, this catalytic system facilitates an asymmetric three-component reaction involving sulfonamides, α-aryldiazoacetates, and imines, expanding the synthetic utility of this methodology.
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