76115-35-0Relevant academic research and scientific papers
Oxidation of bisnaphthols to spironaphthalenones, revisited
Khoramabadi-Zad, Ahmad,Yavari, Isaa,Shiri, Azam,Bani, Azad
, p. 1351 - 1358 (2008)
(Chemical Equation Presented) Bis(2-hydroxy-1-naphthyl)methane derivatives have been efficiently converted to their corresponding spirans through three methods, i.e. oxidation by TCCA under mild reaction conditions, Ph3Bi catalyzed air oxidatio
Aerial oxidation of bisnaphthols to spironaphthalenones by a recyclable magnetic core-sell nanoparticle-supported TEMPO catalyst
Khorramabadi-Zad, Ahmad,Daliran, Saba,Oveisi, Ali Reza
, p. 972 - 976 (2013/11/06)
Aerial oxidative cyclization of bisnaphthols to their corresponding mixture of two isomeric spirans 3 and 4 has been carried out using a catalytic amount of magnetic core-shell nanoparticle-supported TEMPO (MNST) combined with a small amount of FeCl3·6H2O. This catalytic system consistently has the advantages of moderate to good yields, low reaction times, mild and convenient conditions, simple experimental and work-up procedure, and of being environmentally benign and highly economic. The magnetically separable MNST catalyst makes it possible for it to be recovered and recycled for several times without significant loss of activity.
Spirans. Part 12. Stereochemical Control in the Oxidative Cyclisation of Bisnaphthols
Bennett, David J.,Dean, Francis M.,Herbin, G. Antonio,Matkin, David A.,Price, Anthony W.,Robinson, Malcolm L.
, p. 1978 - 1985 (2007/10/02)
Almost all oxidising agents cyclise benzylidene-1,1'-bis-2-naphthol (1a) to the stereoisomers (2a) and (3a) of phenylnaphthofuran-2(1H)-spiro-1'(2'H)-naphthalen-2'-one.A few are stereospecific.Hypobromite and persulphate give (2a), whereas iodine oxyacids and (diacetoxyiodo)benzene are specific for (3a).Radical-type oxidants such as hexacyanoferrate(III) and 2,4-di-t-butyl-6-phenylphenoxyl (4) give mixtures.Horseradish peroxydase behaves like hexacyanoferrate(III).The presence in the benzylidene residue of methoxy, nitro, fluoro, and other groups has little effect upon the isomer ratios, which are believed to be determined mainly by the bulk of the benzylidene group and the limits it imposes upon conformations during the oxidation processes.Oxidation by (diacetoxyiodo)benzene occurs through a cyclic intermediate (9) and gives the less-hindered (3a); oxidation of hypobromite occurs not directly but by exchange through an aryl hypobromite (Scheme) which halogenates its opposite naphthol nucleus and then substitutes the halogen, with inversion, thus leading to the more-hindered isomer (2a).
