Development of chiral phosphoric acids based on ferrocene-bridged paracyclophane frameworks

Jérémy Stemper (1) , Kevin Isaac (1) , Julien Pastor (2) , Gilles Frison (2) , Pascal Retailleau (1) , Arnaud Voituriez (1) , Jean-François Betzer (1) , Angela Marinetti (1)

1 ICSN - Institut de Chimie des Substances Naturelles
2 DCMR - Laboratoire des mécanismes réactionnels

This work deals with the development of a new family of planar chiral phosphoric acids, based on a ferrocenophane/paracyclophane scaffold. The synthetic approach has been improved by taking advantage of a chiral phosphorylating agent to access enantiomerically enriched acids via diastereomers separation. These phosphoric acids have been used as catalysts for the enantioselective H-transfer reduction of alpha-substituted quinolines with Hantzsch esters. Optimization of both the catalyst and the Hantzsch reductant allowed ee in the range 82-92% to be attained starting from alpha-arylquinolines.

Mots clés: phosphoric acid; planar chirality; chiral phosphorodiamidites; paracyclophanes; organocatalysis

Domaines: Catalyse; Chimie organique; Chimie théorique et/ou physique

Jérémy Stemper, Kevin Isaac, Julien Pastor, Gilles Frison, Pascal Retailleau, et al.. Development of chiral phosphoric acids based on ferrocene-bridged paracyclophane frameworks. Advanced Synthesis and Catalysis, 2013, 355, pp.3613-3624. ⟨10.1002/adsc.201300697⟩. ⟨hal-00872550⟩