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.
研究了易于合成甚至商业可得的(S)-脯氨酸衍生物在氯化三氯硅烷介导的酮肟还原反应中的行为。考虑了一小组结构和电子修饰的的手性Lewis碱;这些化合物能够促进不同底物的对映选择性还原,并得到良好的化学产率。在HSiCl3添加到模型底物N-苯基乙酰苯胺肟的反应中,所选择的有机催化剂导致形成相应的胺,具有很好的立体选择性,最高可达75%的ee值。还进行了理论研究,以阐明立体选择性的来源。