Proline-Based N-Oxides as Readily Available and Modular Chiral Catalysts. Enantioselective Reactions of Allyltrichlorosilane with Aldehydes

[reaction: see text]. A proline-based N-oxide is identified that serves as an effective catalyst for the reaction of allyltrichlorosilane with aryl and alpha,beta-unsaturated aldehydes at room temperature to afford the desired homoallylic alcohols in up to 92% ee. The chiral catalyst can be easily prepared from optically pure proline in three simple steps and 60% overall yield.