Optimization and Gram-scale Preparation of S-Trifluoromethyl- Sulfoximines and Sulfilimino iminiums, Powerful Reagents for the Late Stage Introduction of the CF3 Group

S- trifluoromethylsulfoximine and S- trifluoromethylsulfilimino iminiumsare important reagents for the electrophilic or radical late-stage introduction of the CF3 group. We disclose in this article a reappraisal of our previous methodologies and their adaptation to a large scale. More than 30 g of the key sulfoximine 4 and 40 g of S- trifluoromethylsulfilimino iminium5 are prepared without purification. DSC measurements have been performed on both the crude mixture and the isolated compounds in order to insure a safe process. The cost of the synthesis is also detailed and discussed.