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TFA-Promoted Cascade Sulfonylation/Rearrangement/Cyclization of 1,5-Diynols and Sodium Sulfinates to Construct Sulfonylated Benzo[ b ]fluorenes.

Shimin JiangMeng LiangJiang BaiRuchun YangXi ChenHaiyang HuangHai-Xin DingMu-Jia LuoXian-Rong SongQiang Xiao
Published in: The Journal of organic chemistry (2024)
A novel conversion of 1,5-diynols into sulfonylated benzo[ b ]fluorenes is reported by a TFA-promoted cascade cyclization with sodium sulfinates under mild conditions. This strategy provides an efficient and practical approach for accessing various sulfonated benzo[ b ]fluorenes in moderate to excellent yields under metal-free conditions. On the basis of the control experimental results and density functional theory calculations, a possible cascade transformation mechanism consisting of the dehydration of propargylic alcohols, sulfonylation, allenylation, and Schmittel-type cyclization is proposed. It is worth noting that TFA played an important role in this cascade cyclization, which promoted C-SO 2 R bond cleavage in a propargylic sulfone intermediate to form allenyl sulfones, followed by Schmittel-type cyclization to give the target product.
Keyphrases
  • density functional theory
  • molecular dynamics
  • transition metal