title: Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives.
abstract: The behavior of readily synthesized and even commercially available (S)-proline derivatives, was studied in the trichlorosilane-mediated reduction of ketoimines. A small library of structurally and electronically modified chiral Lewis bases was considered; such compounds were shown to promote the enantioselective reduction of different substrates in good chemical yields. In the HSiCl3 addition to the model substrate N-phenylacetophenone imine, the organocatalyst of choice led to the formation of the corresponding amine with good stereoselectivity, up to 75% ee. Theoretical studies were also performed in order to elucidate the origin of the stereoselection.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, I-20133 Milano, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Bonsignore
authors.forename: Maurizio
authors.initials: M
authors.lastname: Benaglia
authors.forename: Laura
authors.initials: L
authors.lastname: Raimondi
authors.forename: Manuel
authors.initials: M
authors.lastname: Orlandi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Celentano
keywords: Lewis bases; chiral prolines; imine reduction; organocatalysis; trichlorosilane