Complementary Site-Selective Sulfonylation of Aromatic Amines by Superacid Activation.
Paul BourbonEmeline AppertAgnès Martin-MingotBastien MicheletSébastien ThibaudeauPublished in: Organic letters (2021)
Under superacidic conditions, aniline and indole derivatives are sulfonylated at low temperature with easy-to-access arenesulfonic acids or arenesulfonyl hydrazides. By modification of the functional-group directing effect through protonation, this method allows nonclassical site functionalization by overcoming the innate regioselectivity of electrophilic aromatic substitution. This superacid-mediated sulfonylation of arenes is complementary to existing methods and can be applied, through protection by protonation, to the late-stage site-selective functionalization of natural alkaloids and active pharmaceutical ingredients.
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