Stereoselective Reduction of Imines with Trichlorosilane Using Solid-Supported Chiral Picolinamides

• Main Authors: Sílvia D. Fernandes, Riccardo Porta, Pedro C. Barrulas, Alessandra Puglisi, Anthony J. Burke, Maurizio Benaglia
• Format: Article
• Language: English
• Published: MDPI AG 2016-09-01
• Series: Molecules
• Subjects: supported catalysis; catalytic reactors; trichlorosilane; chiral picolinamides; organocatalysis; flow chemistry
• Online Access: http://www.mdpi.com/1420-3049/21/9/1182

The stereoselective reduction of imines with trichlorosilane catalyzed by chiral Lewis bases is a well-established procedure for the synthesis of enantio-enriched amines. Five supported cinchona-based picolinamides have been prepared and their activity tested in a model reaction. The comparison of different supporting materials revealed that polystyrene gave better results than silica in terms of stereoselectivity. The applicability of the solid-supported catalyst of choice to the reduction of different imines was also demonstrated. Additionally, for the first time, a catalytic reactor containing a polymer-immobilized chiral picolinamide has been employed for the stereoselective reduction of imines with trichlorosilane under continuous flow conditions.