Mn(OAc)3-Mediated Unexpected Cycloannulative Sulfonyl Migration Cascade using (E)-?-Iodovinyl Sulfones and ortho-Alkynylphenols for Direct Synthesis of Chromene-Derived Vinyl Sulfones

Cycloannulative sulfonyl migration has received much attention; however, a carbon-to-carbon sulfonyl group shift still needs to be discovered. We hereby report a base-mediated oxaMichael addition-elimination of (E)-fi-iodovinyl sulfones with ortho-alkynylphenols, followed by cycloisomerization and unique stereoselective sulfonyl migration in one-pot, is realized under the influence of Mn(OAc)3 center dot 2H2O. A broad range of vinyl sulfonetethered chromenes were readily accessed in moderate to high yields with good functional group compatibility. Notably, the reaction was robust at the gram scale, and postsynthetic transformations were successfully uncovered. Moreover, plausible mechanistic pathways were rationalized on the basis of existing experimental results.

Automated summary

A base-mediated one-pot reaction involving oxaMichael addition-elimination, cycloisomerization, and stereoselective sulfonyl migration has been developed for the synthesis of vinyl sulfonetethered chromenes. The reaction exhibited good functional group compatibility and gram-scale robustness, and the corresponding postsynthetic transformations were successful. Plausible mechanistic pathways were proposed based on experimental results.