Synthesis of 4-Difluoromethylquinolines by NHC-Catalyzed Umpolung of Imines

A. Patra (1) , Fabien Gelat (2) , Xavier Pannecoucke (2) , Thomas Poisson (2) , Tatiana Besset (2) , A.T. Biju

1 PPSM - Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires
2 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse

The N-heterocyclic carbene (NHC)-catalyzed umpolung of aldimines for the synthesis of 4-difluoromethylquinoline derivatives is reported. In the presence of NHCs, the intramolecular cyclization of aldimines bearing a moderately electron-poor double bond due to the presence of the −CF3 group likely proceeds via the intermediacy of the aza-Breslow intermediate. The key to the success of this aza-Stetter type transformation is the NHC generated from the bicyclic triazolium salt using DBU as the base.

Domaines: Chimie

A. Patra, Fabien Gelat, Xavier Pannecoucke, Thomas Poisson, Tatiana Besset, et al.. Synthesis of 4-Difluoromethylquinolines by NHC-Catalyzed Umpolung of Imines. Organic Letters, 2018, 20 (4), pp.1086-1089. ⟨10.1021/acs.orglett.7b04055⟩. ⟨hal-02024525⟩