Unveiling the Use of 1,1-Bis(triflyl)ethylene as CF 3 SO 2 CH═CH 2 Source with the Assistance of ( n -Bu) 4 NF: Synthesis of 3-[(Trifluoromethyl)sulfonyl]cyclobut-1-enes.

Allylic sulfone-embedded cyclobutenes have been prepared in one pot from alkynes. The carbocycle and the alkenyl sulfone moieties were installed through consecutive bis(triflyl)cyclobutenylation of a triple bond and tetra- n -butylammonium fluoride (TBAF)-assisted hydrodesulfonylation of an allylic bis(sulfone). It is noteworthy that 1,1-bis(triflyl)ethylene acts as a CF 3 SO 2 CH═CH 2 source for the first time.