602-09-5Relevant articles and documents
ortho-Selective phenol-coupling reaction by anodic treatment on boron-doped diamond electrode using fluorinated alcohols
Kirste, Axel,Nieger, Martin,Malkowsky, Itamar M.,Stecker, Florian,Fischer, Andreas,Waldvogel, Siegfried R.
, p. 2273 - 2277 (2009)
A study was conducted to demonstrate ortho-selective phenol-coupling reaction by anodic treatment on boron-doped diamond electrode using fluorinated alcohols. A protocol for the conversion of neat phenol on boron-doped diamond (BDD) electrodes was also developed for the study. Partial conversion of 30% was carried out to prevent electrochemical incineration and to avoid by-products. It was observed that the free path length of oxyl radicals generated on BDD electrodes were found in the nanometer range. Methanol and other simple alcohols were used in the study on the anodic phenol coupling reaction. It was also found that some amount of methanol disappeared from the electrolysis cell despite cooling the electrolyte. Hexafluoroisopopanol with supporting electrolytes produced a powerful electrolyte system for the anodic coupling reaction of phenols.
An efficient and practical direct resolution of racemic 1,1'-bi-2-naphthol to both of its pure enantiomers
Hu,Vitharana,Pu
, p. 2123 - 2126 (1995)
An efficient and practical method to directly resolve racemic 1,1'-bi-2-naphthol, rac-1, into optically pure R and S-1 has been developed by modification of a N-benzylcinchonidium chloride resolution procedure. In a typical experiment, 60 g of rac-1 is resolved to give 22.5 g of R-1 (75%, >99% ee) and 21 g of S-1 (70%, >99% ee). The chiral resolving agent, (8S,9R)-(-)-N-benzylcinchonidinium chloride, 2, is recovered in 80% yield.
Visible Light-Promoted C-C Bond Formation from Hydroxyaryls in Water
Saporito, Dafne,Rodriguez, Sergio A.,Baumgartner, Maria T.
, p. 978 - 982 (2019)
An eco-friendly and direct arylation of hydroxyaryls in water using photoinduced reactions with different substrates (1-bromo-2-naphthol, 1-iodo-2-naphthol, N-(2-iodophenyl)acetamide, 5-bromouracil, 2-iodo-N-methylbenzamide, and 2-iodobenzamide) was studied. For example, π-expanded coumarins, compounds with potential optical applications, were synthesized in very high yield, without the use of toxic reagents, in a one-pot reaction. In addition, we demonstrate that the irradiation source (halogen lamp) can be efficiently replaced by an LED without altering the reaction yield.
Novel horseradish peroxidase catalysed enantioselective oxidation of 2-naphthols to 1,1'-binaphthyl-2,2'-diols
Sridhar, Madabhushi,Vadivel, Subramanian K.,Bhalerao, Uday T.
, p. 5695 - 5696 (1997)
Enantioselective oxidation of 2-naphthols to 1;1'-binaphthyl-2,2'-diols catalysed by horseradish peroxidase is described.
Resolution of Racemic 1,1'-Bi-2-naphthol Using (S)-Proline via a Cyclic Borate Ester
Shan, Zixing,Xiong, Ying,Zhao, Dejie
, p. 3893 - 3896 (1999)
1,1'-Bi-2-naphtholborane generated from racemic 1,1'-bi-2-naphthol and borane dimethyl sulfide complex reacted with (S)-proline in tetrahydrofuran to form a spirocyclic 1,1'-bi-2-naphtholboric proline anhydride. Its two diastereoisomers could be separated efficiently under the experimental conditions, from which enantiomerically pure (R)-(+)- and (S)-(-)-1,1'-bi-2-naphthol were obtained in ca. 80 percent overall yield, respectively. - Keywords: resolution; 1,1'-bi-2-naphthol; (S)-proline; cyclic borate ester.
Metal-free carbon as a catalyst for oxidative coupling: Solvent-enhanced poly-coupling with regioselectivity
Shaikh, Melad,Sahu, Aanchal,Kiran Kumar,Sahu, Mahendra,Singh, Sunil. K.,Ranganath, Kalluri V. S.
, p. 4533 - 4537 (2017)
Herein, heterogeneous, inexpensive, metal-free, and environmentally friendly graphene oxide (GO) was developed for the oxidative polycoupling of 2-naphthols in aqueous sodium hydroxide in the presence of air. This study demonstrates that GO can function as a heterogeneous catalyst, and solvent plays a vital role in the coupling. Upon changing the solvent from toluene to water, transformation of products from homocoupling to polycoupling materials occurs.
Oxidation of 2-naphthol in the presence of catalysts based on modified β-cyclodextrins
Karakhanov,Kardahseva,Maksimov,Egazar'Yants,Karapetyan,Zatolochnaya
, p. 402 - 408 (2007)
The oxidation of 2-naphthol to 1,1'-bi-2-naphthol in a biphasic system in the presence of β-cyclodextrins was studied. It was found that the use of macrocyclic receptors leads to substantial enhancement of the activity of catalytic systems. It was shown that the product yield and the reaction rate substantially increase when ligands obtained via molecular imprinting in the presence of 1,1'-bi-2-naphthol as a template are added.
Oxidative coupling of 2-naphthol catalyzed by a new methoxido bridged dinuclear oxidovanadium(V) complex
Noshiranzadeh, Nader,Bikas, Rahman,Emami, Marzieh,Siczek, Milosz,Lis, Tadeusz
, p. 167 - 172 (2016)
A new dinuclear oxidovanadium(V) complex, [(VO)2(μ-L-κ4O,N,N,O)(μ-OCH3)2(OMe)2]·CH3OH (1), is synthesized by the reaction of V2O5 with 1,1′-((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(naphthalen-2-ol) (H2L) in methanol. H2L is synthesized by two different methods: (i) from the reaction of hydrazine hydrate with 2-hydroxy-1-naphthaldehyde and (ii) from the reaction of hydrazine hydrate with 2-naphthol in the presence of formaldehyde (Mannich condensation). The ligand and its vanadium complex are characterized by elemental analysis, spectroscopic methods (FT-IR, NMR and UV-Vis) and their structures are determined by single crystal X-ray analysis. X-ray studies show that 1 is a neutral dinuclear complex of oxidovanadium(V) in which two vanadium(V) ions are connected by two methoxido bridging groups. The Schiff base ligand is coordinated to both vanadium centers by two NO-donor sets. Complex 1 is employed as initiator for oxidative coupling of 2-naphthol to produce BINOL. The effect of temperature, reaction atmosphere and solvent in catalytic reaction is studied. According to the obtained results, a mechanism is proposed for catalytic oxidative coupling reaction in the presence of complex 1.
Supramolecular Ammine-Copper rac-BINOLAT Salts through in-situ R- or S-BINOL Racemization
Wisser, Barbara,Labahn, Andreas,N?ther, Christian,Janiak, Christoph
, p. 734 - 739 (2020)
The molecule rac-1,1'-binaphthalene-2,2'-diol (rac-1,1'-bi-2-naphthol, rac-BINOL) shows a propensity for supramolecular, charge-assisted O–H···O– hydrogen-bonded strand formation when crystallized with its deprotonated form BINOLAT2– and Cu2+ in conc. ammonia. The naphthyl-paneled cavities in the {(rac-BINOLAT2–)(rac-BINOL)2} strands host the [Cu(NH3)5]2+-guest cation through second-sphere N–H···O hydrogen bonding in the structure of [Cu(NH3)5]2+(rac-BINOLAT2–)(rac-BINOL)2. Decreasing the copper(II) and ammonia concentrations in the crystallization leads to {(rac-BINOLAT2–)(rac-BINOL)} strands, in which rac-BINOLAT2– coordinates to two copper(II) atoms in the structure of [Cu(NH3)2(μ-rac-BINOLAT2–-κ2O,O':κO)]2(rac-BINOL)2. In the {Cu2+(NH3)2} moiety two BINOLAT-oxide atoms act as bridging ligands. Both copper structures could be obtained by using the racemic rac-BINOL or the enantiomeric R- or S-BINOL, through an in-situ racemization of the latter.
A practical procedure for the solid-phase synthesis of racemic 2,2'-dihydroxy-1,1'-binaphthyl
Rasmussen,Axelsson,Tanner
, p. 4027 - 4030 (1997)
A high yielding solid-phase dimerisation of 2-naphthol by means of a ball-milling procedure is described.
