Organocatalysis with Chiral Formamides: Asymmetric Allylation and Reduction of Imines

✍ Scribed by Christine Baudequin; Devdutt Chaturvedi; Svetlana B. Tsogoeva

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 131 KB
• Volume: 2007
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/ejoc.200700058

✦ Synopsis

Abstract

Simple aldimine, derived from p‐nitrobenzaldehyde and 2‐aminophenol, reacts with allyltrichlorosilane in the presence of chiral N‐formylproline activator 5 and an L‐proline additive to afford the corresponding homoallylic amine in good yield (84 %) and with moderate enantioselectivity (43 % ee). The role of the second formamide moiety in the activator is crucial to bring about the enhancement in the reaction rate and enantioselectivity, as C~2~‐chiral bisformamide 1 promotes for the same allylation reaction in higher yield (94 %) and enantioselectivity (83 % ee). Chiral monoformamide 5 (10 mol‐%), with the assistance of HMPA as an additive, also catalyses the asymmetric reduction of ketimine 13 in the presence of trichlorosilane in good yield and enantioselectivity (75 %, 81 % ee). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)