title: Highly enantioselective synthesis of naphthoquinones and pyranonaphthoquinones catalyzed by bifunctional chiral bis-squaramides.
abstract: 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.
authors: Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal-462 066, India.
authors: Nagaraju
authors: N
authors: Molleti
authors: Vinod K
authors: VK
authors: Singh
mesh_terms: D000577:Amides / Q000737:chemistry*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002384:Catalysis; D009285:Naphthoquinones / Q000138:chemical synthesis* / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
chemical_list: D000577:Amides; D009285:Naphthoquinones