Diastereo- and Enantioselective Synthesis of Spiro-Pyrrolidine-Pyrazolones by Squaramide-Catalyzed Cascade Aza-Michael/Michael Reactions

作者：Li, Jun-Hua; Wen, Hongliang; Liu, Lei; Du, Da-Ming^*

来源：European Journal of Organic Chemistry, 2016, 2016(14): 2492-2499.

DOI：10.1002/ejoc.201600316

• Asymmetric synthesis
• Organocatalysis
• Domino reactions
• Michael addition
• Spiro compounds
• Nitrogen heterocycles

A new method was developed to rapidly generate a series of spiro-pyrrolidine-pyrazolones by using a squaramide-catalyzed cascade aza-Michael/Michael addition of either tosyl-aminomethyl enones or enoates to unsaturated pyrazolones. This tandem reaction sequence proceeded well by using 5 mol-% of a chiral bifunctional tertiary amine squaramide catalyst to afford the desired products in good to excellent yields (up to 98 %) with excellent diastereoselectivities [up to >20:1 diastereomeric ratio (dr)] and high to excellent enantioselectivities (up to 98 % ee).

• 出版日期2016-5
• 单位北京理工大学