377767-76-5Relevant academic research and scientific papers
Synergistic dual activation catalysis by palladium nanoparticles for epoxide ring opening with phenols
Seth, Kapileswar,Roy, Sudipta Raha,Pipaliya, Bhavin V.,Chakraborti, Asit K.
supporting information, p. 5886 - 5888 (2013/07/25)
Synergistic dual activation catalysis has been devised for epoxide phenolysis wherein palladium nanoparticles induce electrophilic activation via coordination with the epoxide oxygen followed by nucleophilic activation through anion-π interaction with the aromatic ring of the phenol, and water (reaction medium) also renders assistance through 'epoxide-phenol' dual activation.
2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2- diazaphosphorine supported on polystyrene (PS-BEMP) as an efficient recoverable and reusable catalyst for the phenolysis of epoxides under solvent-free conditions
Zvagulis, Artis,Bonollo, Simona,Lanari, Daniela,Pizzo, Ferdinando,Vaccaro, Luigi
supporting information; scheme or table, p. 2489 - 2496 (2010/12/29)
2-tert-Butylimino-2-diethylamino-1,3-dimethylperhydro-1,3, 2-diazaphosphorine supported on polystyrene (PS-BEMP) is an efficient catalyst for the ring-opening of epoxides with phenols (1.0 equiv.). Excellent yields have been obtained and in most of the cases the final products have been isolated in pure form without any additional purification step. E-factors associated to this protocol are small and further improvements were obtained by setting a cyclic continuous-flow reactor operating under solvent-free conditions (SolFC) that allowed us to minimize waste and reduce the E-factor by 95% compared to batch conditions. In addition the representative synthesis of a 2,3-dihydrobenzo[1,4]dioxepin-5-one has been realized. Optimization of this process was achieved by setting up an automated multi-step continuous-flow reactor based on a phenolysis process and a subsequent lactonization by thermal treatment of the reaction mixture. 3-Phenoxymethyl-2,3-dihydrobenzo[e][1,4] dioxepin-5-one was isolated in pure form and on a multi-gram scale in a very satisfactory 86% overall yield and an E-factor of 1.47.
A new regio- and stereoselective intermolecular Friedel-Crafts alkylation of phenolic substrates with aryl epoxides
Bertolini, Ferruccio,Crotti, Paolo,Macchia, Franco,Pineschi, Mauro
, p. 61 - 64 (2007/10/03)
A conceptually new regioselective and highly syn-stereoselective intermolecular Friedel-Crafts-type O-alkylation of phenols with aryl epoxides by the use of appropriately substituted aryl borates is reported. The carbon-carbon bond formation occurs in neutral and mild conditions without the need for external Lewis acids or transition metal catalysts.
Oxidation of non-phenolic β-O-aryl-lignin model dimers catalysed by lignin peroxidase. Comparison with the oxidation induced by potassium 12-tungstocobalt(III)ate
Baciocchi, Enrico,Bietti, Massimo,Gerini, Maria Francesca,Lanzalunga, Osvaldo,Mancinelli, Simona
, p. 1506 - 1511 (2007/10/03)
The H2O2-promoted oxidations of the non-phenolic β-O-aryl-lignin model dimers 1-(3,4-dimethoxyphenyl)-2-phenoxyethanol (1) and 2-(4-methoxyphenoxy)-1-phenylethanol (2) catalysed by LiP at pH = 4.0 have been studied. The oxidation of 1 mainly leads to the corresponding ketone, indicating that the prevailing reaction of the intermediate radical cation 1 +. is Cα-H deprotonation. The oxidation of 2 forms 2-(4-methoxyphenoxy)2-phenylethanol (7, an isomer of 2), 2-phenyl-1,4-dioxaspiro[4.5]deca-6,9-dien-8-one (8) and products coming from the cleavage of the C-C bond γ to the more electron rich ring. The formation of all these products can be rationalised by assuming that the main reaction of the intermediate 2+. is a nucleophilic attack of the alcoholic OH group on the ring bearing the positive charge. This leads to a spirocyclohexadienyl radical, which either is then oxidised to the dioxaspirodecadienone 8 or undergoes ring opening to give an alkoxyl radical from which the isomer of 2 and the C-C bond cleavage products may form. Support for this mechanism has been provided by a study of the oxidation of 4-MeOC6H4OCH2CD2OH and by comparing the results with those obtained when the alkoxyl radical 4-MeOC6H4OCH2CD2O. was generated from 4-MeOC6H4OCH2CD2OOtBu. The oxidation of 1 induced by the genuine one-electron oxidant potassium 12-tungstocobalt(III)ate at pH = 4.0 confirms the results obtained with LiP. However, under the same conditions, no fragmentation products were observed in the oxidation of 2, probably due to a fast oxidation, by potassium 12-tungstocobalt(III)ate, of the spirocyclohexadienyl radical.
