Highly Enantioselective Synthesis of Spiro[cyclohexanone‐oxindoles] and Spiro[cyclohexanone‐pyrazolones] by Asymmetric Cascade [5+1] Double Michael Reactions

作者：Bin Wu, Jian Chen, Mei‐Qiu Li, Jin‐Xin Zhang, Xiaoping Xu, Shun‐Jun Ji, Xing‐Wang Wang · 发表于：European Journal of Organic Chemistry · 年份：2012 · DOI：10.1002/ejoc.201101529 · 被引用次数：101 · 研究领域：Asymmetric Synthesis and Catalysis、Synthesis and Catalytic Reactions、Chemical synthesis and alkaloids

Abstract The asymmetric catalytic synthesis of naturally occurring and biologically active spiro compounds is a challenge for modern chemical methodology. Here we report the construction of spiro compounds through cascade [5+1] double Michael reactions between divinyl ketones and N‐unprotectedoxindoles or N‐phenyl‐protected pyrazolones catalyzed by a combination of the easily available 9‐amino‐9‐deoxy‐epi‐quinine with N‐Boc‐D‐phenylglycine. The desired multistereogenic spiro[cyclohexanone‐oxindoles and ‐pyrazolones] were obtained with high yields (up to 98 %) andstereoselectivities (up to >20:1 dr, 99 % ee).