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、Xiao-Ping Xu、Shun-Jun Ji、Xing-Wang Wang
DOI:10.1002/ejoc.201101529
日期:2012.3
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