Georg Manolikakes

Sulfones are versatile building blocks in organic synthesis and have found diverse applications in agroscience, medicine or materials. Typical methods for the synthesis of sulfones include the oxidation of sulfides, alkylation of sulfinates, addition of sulfonyl-type radicals to alkenes or alkynes or electrophilic sulfonlyation of arenes.[1] In recent years, the direct sulfonylation of C-H-bonds has become an attractive alternative to such reactions based on prefunctionalized starting materials.[2]
Herein we report three novel methods for the synthesis of sulfones via the selective functionalization of C(sp2)-H-bonds with sodium and lithium sulfinates:
i) A copper-mediated ortho-selective sulfonylation of benzoic acid derivatives;[3|
ii) A copper-catalyzed remote sulfonylation of the 8-aminoquinoline scaffold;[4]
iii) A copper-catalyzed para-selective sulfonylation of anilines.[5]
Based on these reactions, we could develop straightforward procedures for the rapid construction of sulfones starting from organolithium reagents and sulfur dioxide.

In summary, our novel methods enable a mild and efficient synthesis of sulfones from readily available starting materials via a regioselective functionalization of C(sp2)-Hbonds.

References:
[1] N.-W. Liu, S. Liang, G. Manolikakes, Synthesis 2016, 1939;
[2] C. Shen, P. Zhang, Q. Sun, S. Bai, T. S. A. Hor, X. Liu, Chem. Soc. Rev. 2015, 44, 291;
[3] S. Liang, N.-W. Liu, S. Liang, Adv. Synth. Cat. 2016, 358, 159;
[4] S. Liang, G. Manolikakes, Adv. Synth. Cat. 2016, 358, 2371;
[5] S. Liang, M. Bolte, G. Manolikakes, Chem. Eur. J. 2017, 23, 96.