N V G Moorthy, Dyapa Rajendar, Pansare Sunil V
Department of Chemistry, Memorial University , St. John's, Newfoundland, Canada A1B 3X7.
Org Lett. 2015 Nov 6;17(21):5312-5. doi: 10.1021/acs.orglett.5b02677. Epub 2015 Oct 22.
The first examples of an organocatalytic Michael addition of a ketone to in situ generated α-nitrostyrenes are reported. A suitably functionalized γ-nitroketone obtained from the organocatalyzed Michael addition was converted into (+)-2-epi-lasubine II, the immediate synthetic precursor of (+)-lasubine II and (-)-subcosine II (enantiomers of the natural quinolizidine alkaloids). Two of the three stereocenters in (+)-2-epi-lasubine II are set by the Michael reaction.
报道了首例酮对原位生成的α-硝基苯乙烯进行有机催化迈克尔加成反应的实例。通过有机催化迈克尔加成反应得到的适当官能化的γ-硝基酮被转化为(+)-2-表拉苏宾II,它是(+)-拉苏宾II和(-)-亚可辛II(天然喹诺里西啶生物碱的对映体)的直接合成前体。(+)-2-表拉苏宾II中的三个立体中心中有两个是由迈克尔反应构建的。