Visible light amination/Smiles cascade: access to phthalazine derivatives

Etienne Brachet (1) , Leyre Marzo , Mohamed Selkti (2) , Burkhard König (3) , Philippe Belmont (1)

1 COMETE - UMR 8638 - Chimie Organique, Médicinale et Extractive et Toxicologie Expérimentale
2 LCRB - UMR 8015 - Laboratoire de cristallographie et RMN biologiques
3 Institut für Organische Chemie

We report the synthesis of various phthalazines via a new cascade reaction, initiated by visible light photocatalysis, involving a radical hydroamination reaction followed by a radical Smiles rearrangement. Phthalazine derivatives are obtained in high yields and from a broad scope readily accessible ortho-alkynylsulfonohydrazone precursors. The mild photoredox conditions ensure an excellent functional group tolerance. Application of this strategy to a one-pot protocol starting from the corresponding carbonyl compounds, and subsequent functionalization allow the rapid synthesis of structurally diverse structures.

Domains: Chemical Sciences

Etienne Brachet, Leyre Marzo, Mohamed Selkti, Burkhard König, Philippe Belmont. Visible light amination/Smiles cascade: access to phthalazine derivatives. Chemical Science, 2016, 7 (8), pp.5002-5006. ⟨10.1039/C6SC01095D⟩. ⟨hal-02384218⟩