Highly Regioselective and Stereoselective Radical Addition of p-TsBr to Substituted Terminal Allenes and Their Nucleophilic Substitutions: Synthesis of α,β-Unsaturated Sulfones

Abstract

Regioselective and stereoselective radical addition of p-TsBr to substituted allenes in the presence of a catalytic amount of AIBN afforded tosyl-substituted primary (E)-allylic bromides as the sole products. The nucleophilic substitution of the resulting allylic bromides to give substituted α,β-unsaturated sulfone derivatives is described.

Keywords

allenes - radical reactions - sulfones - nucleophilic substitutions

References

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7

The E stereochemistry of 3a, 3b, 3d, and 3e was confirmed by ¹H NMR NOE experiments (Figure).

Figure