Molleti Nagaraju, Singh Vinod K
Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal-462 066, India.
Org Biomol Chem. 2015 May 14;13(18):5243-54. doi: 10.1039/c5ob00105f.
A variety of enantioenriched naphthoquinones have been synthesized in high yields and excellent enantioselectivities (up to >99% ee) using a bifunctional chiral bis-squaramide catalyzed conjugate addition of 2-hydroxy-1,4-naphthoquinone to 2-enoylpyridines. Some of the Michael products have been successfully converted into various enantioenriched pyranonaphthoquinone derivatives. The protocol is further extended to the synthesis of various 4-hydroxycoumarin derivatives under mild conditions.
使用双功能手性双方酰胺催化2-羟基-1,4-萘醌与2-烯酰基吡啶的共轭加成反应，已以高产率和优异的对映选择性（高达>99% ee）合成了多种对映体富集的萘醌。一些迈克尔加成产物已成功转化为各种对映体富集的吡喃萘醌衍生物。该方法在温和条件下进一步扩展到各种4-羟基香豆素衍生物的合成。
