771-15-3Relevant academic research and scientific papers
Substituent-induced regioselective hydroxylation of the aromatic C-H bond on naphthalene with metachloroperbenzoic acid catalyzed by F20TPPMnCl
Chen, Chang-Di,Sheng, Wen-Bing,Shi, Guo-Jun,Guo, Can-Cheng
, p. 23 - 29 (2013/03/13)
The regioselective hydroxylation of the aromatic C-H bond on a series of naphthalenes with different β-substituent R (R = H, Me, Et, i-Pr, OMe, COOH, Br, etc.) was studied, and the substituent effect on the regioselectivity was investigated. The electron-donating substituent afforded the aromatic C-H bond hydroxylation at the 1α position with more than 80% selectivity, while the electron-withdrawing substituent afforded the aromatic C-H bond hydroxylation at the 4α position with more than 60% selectivity of β-substituted naphthalene hydroxylated with metachloroperbenzoic acid catalyzed by tetrakis(pentafluorophenyl)porphyrin manganese(III) chloride. The research showed that the steric and electronic effects of the substituent appeared to play a significant role in determining the regioselectivity, and the electronic effect was of more importance than the steric effect of the substituent in the current situation. The studies may provide additional proofs for the stepwise mechanism of the aromatic C-H bond hydroxylation through a cationic intermediate. Copyright
A succinct synthesis of the vaulted biaryl ligand vanol via a dienone-phenol rearrangement
Ding, Zhensheng,Xue, Song,Wulff, William D.
experimental part, p. 2130 - 2146 (2011/10/18)
Vanol is a member of the vaulted biaryl family of ligands and it has been proven to be very effective in a number of asymmetric catalytic reactions. The previous synthesis of vanol, while effective, is limited by the cost of reagents involved. The present work evaluates three different approaches to the synthesis of 3-phenyl-1-naphthol, a key intermediate in the synthesis of vanol. The first approach has its key step as the Michael addition of a benzyl Grignard to methyl cinnamate. In the second approach the key step is the first step, a Reformatsky reaction of ethyl bromoacetate and deoxybenzoin. The final and most-efficient approach involves a dienone-phenol rearrangement of a 4-aryl-1-tetralenone generated in-situ from the reaction of 4-chloro-1-naphthol with AlCl3 and benzene, and preliminary results are reported on the extension of this method to substituted vanol derivatives.
Regiospecific oxyhalogenation of aromatics over SBA-15-supported nanoparticle group IV-VI metal oxides
Saikia,Rajesh,Srinivas,Ratnasamy
scheme or table, p. 190 - 201 (2010/11/05)
TiOx, VOx, MoOx and WOx supported on SBA-15 exhibit efficient catalytic activity for oxyhalogenation of aromatics with the H2O2-halide ion system. Unlike the hitherto known solid catalysts, these reusable catalysts yield the para-halogenated product with 100% selectivity at 298 K and moderate acidic pH (3-5). The catalytic activity was enhanced by five orders of magnitude when supported on SBA-15. Springer Science+Business Media, LLC 2010.
N-Bromosuccinimide as a Regioselective Nuclear Monobrominating Reagent for Phenols and Naphthols
Carre?o, M. Carmen,García Ruano, José L.,Sanz, Gema,Toledo, Miguel A.,Urbano, Antonio
, p. 1241 - 1242 (2007/10/03)
A wide range of substituted phenols and naphthols were regioselectively monobrominated with N-bromosuccinimide, at para position in acetonitrile and at ortho position in carbon disulfide, under mild conditions in good yields. Methylphenols afforded only nuclear bromination products.
PHOTOCHEMISTRY OF α-HALOCYCLOALKANONES AND α,α-DIHALOCYCLOALKANONES. IONIC AND RADICAL PHOTOCHEMICAL CARBON-HALOGEN BOND CLEAVAGE
Sket, Boris,Zupan, Marko
, p. 1745 - 1752 (2007/10/02)
The nature of the photochemical carbon-halogen bond cleavage in α-halo cycloalkanones depends on the halogen atom bonded and on the ring size of the cycloalkanone.In the 2-halo-1-indanone series the amount of radical products increased from iodine to chlorine, while in the case of 2-halo-3,4-dihydro-1(2H)-naphthalenone 43percent for iodo, 32percent for bromo, and 53percent for the chloro derivative were found.On the other hand, photochemical carbon-chlorine bond cleavage in 2,2-dichloro-1-indanone led to only radical products, while the formation of both radical and ionic products inthe ratio 1:1 was observed in the case of 2,2-dibromo-1-indanone.In the 2,2-dihalo-3,4-dihydro-1(2H)-naphthalenone series, the ratio of the radical to ionic products formed strongly depended on the halogen atom bonded: preferential formation of the radical product in the case of the chloro derivative (92percent) in contrast to 94percent of the ionic products in the case of the bromoderivative, was observed.
THE INTERMEDIATES IN THE INTERACTION OF PHENOLS WITH N-BROMOSUCCINIMIDE
Chow, Yuan L.,Zhao, Da-Chuan,Johansson, Carl J.
, p. 2556 - 2564 (2007/10/02)
Phenols react with N-bromosuccinimide to generate 2-bromocyclohexadienone-type intermediates that enolize to 2-bromophenols thermally or photolytically with a wide range of rate constants depending on the parent phenol.A trace amount of acids not only accelerates the rates of the formation and decomposition of the 2-bromodienones, it also promotes the rearrangement of the 2-bromodienones to cross-conjugated 4-bromocyclohexadienones.The enolization of these last compounds affords 4-bromophenols.The occurrence of autocatalysis in dienone decompositions arising from more acidic bromophenols is also established.The reaction is assumed to occur by a bromophilic attack of phenols on the N-Br bond to form unstable hypobromites that rapidly rearrange to the 2-bromocyclohexadienone intermediates.The quantum yield of the photodecomposition of 2-bromo-(2H)-naphthalene-1-one in the vicinity of 365 nm was determined to be unity.
BROMINATION OF KETONES AND PHENOLS WITH 4-(TRIBROMOMETHYL)QUINAZOLINE
Mencarelli, Paolo,Stegel, Franco
, p. 83 - 86 (2007/10/02)
4-(Tribromomethyl)quinazoline, 1, in benzene behaves as a brominating agent towards ketones (in the enol form) and phenols.The reaction has the features of a polar reaction, notwithstanding the nature of the solvent.Ketones and phenols behave as nucleophiles, and attack a bromine atom of the brominating agent.
