66595-74-2Relevant academic research and scientific papers
1,3-Dibromo-5,5-dimethylhydantoin (DBH)/kaolin: An efficient reagent system for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes under solvent-free conditions
Shirini, Farhad,Khaligh, Nader Ghaffari,Ghasem-Abadi, Parisa Ghods,Imanzadeh, Gholam Hossein
, p. 1145 - 1148,4 (2012)
1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to
Green and diasteroselective oxidative cyclization of bisnaphthols to spirans
Alizadeh,Khodaei,Moradi
experimental part, p. 351 - 358 (2010/09/03)
Hydrogen peroxide/MoO3, as an efficient and clean oxidizing system was used to afford diasteroselective oxidative cyclization of bisnaphthols to spirans in ethanol at 60 °C with high yields. Bisnaphthols were prepared by the reaction of a series of aldehydes and 2-naphthol in the presence of a catalytic amount of H3[P(Mo3O 10)4].nH2O (HPA) in refluxing dichloromethane.
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).
