Bismuth(III)‐Triflate‐Catalyzed Highly Diastereoselective Synthesis of Substituted Tetrahydrothiophene via Tandem Isomerization, Michael and Aldol Reactions

Abstract

Bismuth(III)trifluoromethanesulfonate (Bi(OTf)3) catalyzes the reaction of β,γ‐unsaturated ketone and 1,4‐dithiane‐2,5‐diol to afford highly substituted tetrahydrothiophenes via sequential rearrangement, Michael and aldol reactions in good yields. The reaction is highly diastereoselective. Bi(OTf)3 acts as a catalyst for all three reactions.

A Bi(OTf)3-Promoted Hydrosulfonylation of Alkenes with Sulfonyl Hydrazides: An Approach to Branched Sulfones

“…On the basis of the experimental results and previous reports, a plausible reaction pathway for this hydrosulfonation is proposed (Scheme ). The p -toluenesulfonyl hydrazide gives the sulfonyl negative ions. ,, In addition, the key intermediate, α,β-conjugated alkene, will be generated through double-bond migration, , which might coordinate with Bi­(OTf) 3 to produce intermediate II , which is then followed by Michael addition to generate III .…”