Access to [2,1]Benzothiazine S , S -Dioxides from β-Substituted o -Nitrostyrenes and Sulfur

Thi Mo Nguyen , Hoang Anh Cao , Thi Thuong Thuong Cao , Satoki Koyama , Dinh Hung Mac , T .B. Nguyen (1)

1 ICSN - Institut de Chimie des Substances Naturelles

Benzothiazine S,S-dioxides 2 were synthesized by simply heating o-nitrostyrenes with elemental sulfur in 3-picoline with complete atom economy. This reaction was found to occur without any added catalyst and consist of a cascade of reduction of the nitro group, sulfuration of a C-H of the double bond, oxidation of a sulfur atom to its highest oxidation state by the migration of two oxygen atoms from the nitro group and formation of new N-S bond. Furthermore, the method could also be applied to o-nitrocinnamamides and cinnamate esters.

Domaines: Chimie

Thi Mo Nguyen, Hoang Anh Cao, Thi Thuong Thuong Cao, Satoki Koyama, Dinh Hung Mac, et al.. Access to [2,1]Benzothiazine S , S -Dioxides from β-Substituted o -Nitrostyrenes and Sulfur. Journal of Organic Chemistry, 2020, 85 (19), pp.12058-12066. ⟨10.1021/acs.joc.0c00918⟩. ⟨hal-02993871⟩