6391-66-8Relevant articles and documents
-
Akhmedzhanova et al.
, (1974)
-
A Chiral Phenanthroline Ligand with a Hydrogen-Bonding Site: Application to the Enantioselective Amination of Methylene Groups
Annapureddy, Rajasekar Reddy,Jandl, Christian,Bach, Thorsten
, p. 7374 - 7378 (2020/08/06)
A silver-catalyzed amination is reported that occurs at the aliphatic C3-substituent of various quinolones and pyridones. The C-H amination reaction proceeded with high site-and enantioselectivity (14 examples, 83-97% ee). The key to its success is the use of a chiral phenanthroline ligand that is attached via an ethynyl linker to the 8-position of octahydro-1H-4,7-methanoisoindol-1-one. AgPF6 (10 mol %) served as the silver source, PhI.NNs as the nitrene precursor, and 1,10-phenanthroline as the coligand. The reaction outcome can be understood by assuming a nitrene C-H insertion within a hydrogen-bonded silver complex in which a single C-H bond is exposed to the catalytic reaction center.
Simple efficient synthesis of pyranoquinoline alkaloids: Flindersine, khaplofoline, haplamine and their analogues
Thangavel, Dhanabal,Ravindran, Sangeetha,Moonsamy, Gengan Robert,Palathurai, Mohan Subramaniam
, p. 124 - 126 (2008/02/11)
An efficient two step synthesis of pyranoquinoline alkaloids is described. Direct treatment of isoprene with 4-hydroxyquinolin-2(1H)-one in the presence of polyphosphoric acid furnished dihydroflindersine in good yield, and which on dehydrogenation led to a new synthesis of flindersine. Khaplofoline, a linear pyranoquinoline alkaloid, was obtained as a minor product. The syntheses of derivatives are also documented.
A NEW APPROACH TO HEMITERPENOID TRICYCLIC QUINOLONES. SYNTHESIS OF N-METHYLFLINDERSINE, KHAPLOPHOLINE AND OTHER STRUCTURALLY SIMILAR ALKALOIDS
Bravo, Pierfrancesco,Resnati, Giuseppe,Viani, Fiorenza,Cavicchio, Giancarlo
, p. 507 - 512 (2007/10/02)
A new and general synthesis of tricyclic quinolone alkaloids is described which, by cyclization of 3-butenyl-4-hydroxyquinolones promoted by mercury(II) ion or by formic acid, affords pyranoquinolones and pyranoquinolones, respectively, with regio- and site-selectivity better than those obtained employing known methodologies. 3-Butenyl-4-hydroxyquinolones have been reacted with mercury(II) acetate to give, after work-up, the corresponding 2-(chloromercurymethyl)pyranoquinolones, which have been reductively demercurated with sodium borohydride and then dehydrogenated by treatment with DDQ.Alternatively, from the same starting compounds the "linear" isomers are obtained by formic acid-promoted cyclization.N-Methylflindersine, khaplofoline and other structurally similar alkaloids have been obtained.