Lewis base-catalyzed trifluoromethylsulfinylation of alcohols and phenols: modular synthesis of trifluoromethanesulfinate esters

Herein, a Lewis base catalyzed trifluoromethylsulfinylation of alkyl alcohols and phenols with N-(trifluoromethylsulfinyl)phthalimide, which is a bench stable electrophilic trifluoromethylsulfinylating reagent, is presented. As a result, modular synthesis of a series of structurally varied trifluoromethanesulfinate esters with high efficiency has been established. This metal-free and catalytic transformation is further highlighted by broad functional group compatibility, late-stage modification of complex molecules and reuse of phthalimide. Interestingly, the formation of alkenes is observed in the case of 1-indanol under the same reaction conditions. Initial mechanistic studies including F-19 NMR and DFT calculations suggested that O-trifluoromethylsulfinylation occurs between the 1-indanol derivatives and a Lewis base-adduct and the alkenes are formed through elimination.