First Base-Free Catalytic Wittig Reaction

详细信息    查看全文

• 作者：Marie-Luis Schirmer ; Sven Adomeit ; Thomas Werner
• 刊名：Organic Letters
• 出版年：2015
• 出版时间：June 19, 2015
• 年：2015
• 卷：17
• 期：12
• 页码：3078-3081
• 全文大小：284K
• ISSN：1523-7052

文摘

The first base-free catalytic Wittig reaction utilizing readily available Bu₃P (5 mol %) as an organocatalyst is reported. The initial Michael addition of the phosphine to a suitable acceptor substituted alkene ultimately results in the formation of an ylide which is subsequently converted with an aldehyde. The presented ¹H NMR studies actually reveal evidence for the Michael addition and proposed ylide formation. Under the optimized reaction conditions various maleates and fumarates were converted with aromatic, heteroaromatic, and aliphatic aldehydes to evaluate the scope and limitations of this unprecedented reaction. Notably, maleates and fumarates react in a stereoconvergent fashion. The corresponding products were obtained in up to 95% isolated yield and E/Z-selectivities up to 99:1.