Efficient Asymmetric Synthesis of 4H-Chromene Derivatives through a Tandem Michael Addition-Cyclization Reaction Catalyzed by a Salen-Cobalt(II) Complex
作者:Zhenhua Dong、Xiaohua Liu、Juhua Feng、Min Wang、Lili Lin、Xiaoming Feng
DOI:10.1002/ejoc.201001151
日期:2011.1
The asymmetric synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene derivatives was achieved through a tandem Michael addition-cyclization reaction of easily available cyclohexane-1,3-dione and ethyl 2-cyano-3-phenylacrylates. Moderate to good yields (up to 81 %) and high enantioselectivities (up to 89 % ee) were obtained with a chiral salen-cobalt(II) complex. This process was air tolerant and
2-氨基-5-氧代-5,6,7,8-四氢-4H-色烯衍生物的不对称合成是通过容易获得的环己烷-1,3-二酮和乙基2-的迈克尔加成环化反应实现的。氰基-3-苯基丙烯酸酯。使用手性 salen-钴 (II) 复合物获得了中等至良好的产率(高达 81%)和高对映选择性(高达 89% ee)。该过程具有耐空气性且易于执行,为合成手性 4H-色烯衍生物提供了一种有效的方法。