Synthesis of Haloalkyl Esters of Trifluoromethanesulfonic Acid by the Regio- and Stereospecific Addition of Chlorine(I) and Bromine(I) Trifluoromethanesulfonate to Alkenes

Article abstract of DOI:10.1021/jo01300a035

The synthesis of a variety of haloalkyl esters of trifluoromethanesulfonic acid was achieved by the addition of CF3SO2OCl and CF3SO2OBr to alkenes.Addition to simple alkenes such as CH2CH2, CF2CH2, CF2CF2, CF2CFCl, CF2CCl2, CHClCHCl, and CHFCHF occur readily at low temperature to give the esters in high yield.With unsymmetrical alkenes, only one structural isomer is observed in every case.With the hypochlorite, cis- and trans-CHFCHF form a single different diastereomer.With the hypobromite, the same result is observed, and trans-CHClCHCl also gives only one diastereomer.A regio- and stereospecific cis-addition mechanism is proposed.