Reported here for the first time are the synthesis, isolation, and characterization of hypervalent β-haloalkenyl-λ3-bromanes. Exposure of terminal alkynes to p-trifluoromethylphenyl(difluoro)-λ3-bromane activated by BF3-i-Pr2O resulted in fluoro-λ3-bromanation of the triple bonds in a Markovnikov fashion, yielding (E)-β-fluoroalkenyl-λ3-bromanes stereoselectively in good yields. 5-Chloro-1-pentynes undergo domino λ3-bromanation-chlorine shift-fluorination or λ3-bromanation-chlorine shift-alkyl shift-fluorination reaction, depending on the substituents and afford (E)-β-chloroalkenyl-λ3-bromanes stereoselectively in high yields. The β-chloroalkenyl-λ3-bromanes contain three kinds of halogen atoms, F, Cl, and Br, in the molecule.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry