Stereoselective Reduction of Imines with Trichlorosilane Using Solid-Supported Chiral Picolinamides.
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.
Department of Chemistry and Chemistry Center of Évora, School of Science and Technology and Institute for Research and Advanced Studies, University of Évora, Rua Romão Ramalho 59, Évora 7000, Portugal. silvia.fernandes@gmail.com.
Sílvia D
SD
Fernandes
Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy. riccardo.porta@unimi.it.
Riccardo
R
Porta
Department of Chemistry and Chemistry Center of Évora, School of Science and Technology and Institute for Research and Advanced Studies, University of Évora, Rua Romão Ramalho 59, Évora 7000, Portugal. pedro.barrulas@gmail.com.
Pedro C
PC
Barrulas
Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy. alessandra.puglisi@unimi.it.
Alessandra
A
Puglisi
Department of Chemistry and Chemistry Center of Évora, School of Science and Technology and Institute for Research and Advanced Studies, University of Évora, Rua Romão Ramalho 59, Évora 7000, Portugal. ajb@uevora.pt.
Anthony J
AJ
Burke
Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy. maurizio.benaglia@unimi.it.
Maurizio
M
Benaglia
D000577:Amides / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010848:Picolinic Acids / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
D000577:Amides; D007097:Imines; D010848:Picolinic Acids; D012821:Silanes; C003142:picolinamide; C065893:trichlorosilane
catalytic reactors; chiral picolinamides; flow chemistry; organocatalysis; supported catalysis; trichlorosilane