834-25-3Relevant articles and documents
Application of iron (III) complex containing 1,3-di-tert-butyl imidazole cations in synthesis of aryl benzyl ether compounds
-
Paragraph 0030-0031, (2021/04/26)
The invention discloses an application of an iron (III) complex containing 1,3-di-tert-butyl imidazole cations in synthesis of aryl benzyl ether compounds, and particularly relates to a method for synthesizing corresponding aryl benzyl ether compounds by taking di-tert-butyl peroxide as an oxidizing agent and carrying out oxidative coupling reaction on phenolic compounds and toluene compounds. According to the method, the iron (III) complex is used as the catalyst for the first time, and oxidative coupling of the phenolic compound and the toluene compound is realized. The method is the first oxidative coupling reaction of phenolic compounds and benzyl C(sp3)-H bonds, and a new method is provided for synthesizing aryl benzyl ether compounds. Compared with an existing synthesis method, the method provided by the invention avoids using toxic and polluting halogenated hydrocarbon and strong base, has better atom economy, and conforms to the development concept of green synthetic chemistry.
Towards ortho-selective electrophilic substitution/addition to phenolates in anhydrous solvents
Lopu?anskaja, Eleana,Kooli, Anni,Paju, Anne,J?rving, Ivar,Lopp, Margus
, (2021/02/16)
Alkyl-substituted Li-phenolates with BnBr in water solution lead to a mixture of o- and p-Bn-substituted phenols together with a substantial amount of phenol Bn ether. In CPME, and especially in toluene with 1–2 equivalents of ether or alcohol additives, ortho-selective alkylation is achieved. In the case of o,o,p-tri- and o,o-di-substituted phenols dearomatization occurs affording o-Bn-substituted alkyl cyclohexadienones with yields up to 92% with an o/p ratio up to 90/1.
Oxalohydrazide Ligands for Copper-Catalyzed C?O Coupling Reactions with High Turnover Numbers
Ray, Ritwika,Hartwig, John F.
supporting information, p. 8203 - 8211 (2021/03/08)
Here, we report a class of ligands based on oxalohydrazide cores and N-amino pyrrole and N-amino indole units that generates long-lived copper catalysts for couplings that form the C?O bonds in biaryl ethers. These Cu-catalyzed coupling of phenols with aryl bromides occurred with turnovers up to 8000, a value which is nearly two orders of magnitude higher than those of prior couplings to form biaryl ethers and nearly an order of magnitude higher than those of any prior copper-catalyzed coupling of aryl bromides and chlorides. This ligand also led to copper systems that catalyze the coupling of aryl chlorides with phenols and the coupling of aryl bromides and iodides with primary benzylic and aliphatic alcohols. A wide variety of functional groups including nitriles, halides, ethers, ketones, amines, esters, amides, vinylarenes, alcohols and boronic acid esters were tolerated, and reactions occurred with aryl bromides in pharmaceutically related structures.
Synthesis of 6 H-Benzo[ c]chromene Scaffolds from O-Benzylated Phenols through a C-H Sulfenylation/Radical Cyclization Sequence
Karreman, Steve,Karnbrock, Simon B. H.,Kolle, Sebastian,Golz, Christopher,Alcarazo, Manuel
supporting information, p. 1991 - 1995 (2021/04/05)
S-Aryl dibenzothiophenium salts, obtained through a highly regioselective C-H sulfenylation of o-benzyl-protected phenols, are used as precursors of 6H-benzo[c]chromenes. The reaction starts with a photocatalytically triggered single-electron transfer to the sulfonium salt, which promotes the formation of an aryl radical via selective mesolitic cleavage of the S-Arexo bond. Mechanistic studies reveal that this initial radical species cyclizes following a kinetically favored 5-exo-trig pathway. Subsequent ring expansion, favored by rearomatization, delivers the desired tricyclic systems.
An alternative route for boron phenoxide preparation from arylboronic acid and its application for C[sbnd]O bond formation
Joo, Seong-Ryu,Kim, Seung-Hoi,Lim, In-Kyun
, (2020/08/06)
An efficient synthetic route to benzyl phenyl ether preparation has been successfully developed via a one-pot synthetic protocol utilizing a combination of arylboronic acids, hydrogen peroxide (H2O2), and benzyl halides. The whole procedure consists of two consecutive reactions, formation of boron phenoxide from arylboronic acids and its nucleophilic attack. A simple operation under mild conditions such as room-temperature ionic liquid (choline hydroxide), aerobic environment, and absence of metal- and base-catalysts has been employed. Expansion to utilize benzyl surrogates was also successfully accomplished.
Choline Hydroxide as a Versatile Medium for Catalyst-Free O-Functionalization of Phenols
Joo, Seong-Ryu,Kim, Seung-Hoi,Kwon, Gyu-Tae,Park, Soo-Youl
, p. 1200 - 1205 (2020/11/30)
A versatile synthetic protocol for benzyl phenyl ether preparation via O-alkylation of phenolic oxygen with readily available benzyl derivatives was demonstrated. The newly designed procedure was carried out using an eco-friendly medium, room-temperature ionic liquid (choline hydroxide), under metal- and base-catalyst-free aerobic conditions. The reaction platform was also successfully applied to phenol protection strategy.
α-Lithiobenzyloxy as a Directed Metalation Group in ortho-Lithiation Reactions
Sedano, Carlos,Velasco, Rocío,Feberero, Claudia,Suárez-Pantiga, Samuel,Sanz, Roberto
supporting information, p. 6365 - 6369 (2020/08/24)
The α-lithiobenzyloxy group, easily generated from aryl benzyl ethers by selective α-lithiation with t-BuLi at low temperature, behaves as a directed metalation group (DMG) providing a direct access to o-lithiophenyl α-lithiobenzyl ethers. This ortho-directing effect is reinforced in substrates bearing an additional methoxy group at the meta position. The generated dianions can be reacted with a selection of electrophiles including carboxylic esters and dihalosilanes or germanes, which afford interesting benzofuran, sila(germa)dihydrobenzofuran, and silachroman derivatives from simple aryl benzyl ethers.
Palladium-Catalyzed Methylation of Aryl, Heteroaryl, and Vinyl Boronate Esters
Haydl, Alexander M.,Hartwig, John F.
supporting information, p. 1337 - 1341 (2019/02/26)
A method for the direct methylation of aryl, heteroaryl, and vinyl boronate esters is reported, involving the reaction of iodomethane with aryl-, heteroaryl-, and vinylboronate esters catalyzed by palladium and PtBu2Me. This transformation occurs with a remarkably broad scope and is suitable for late-stage derivatization of biologically active compounds via the boronate esters. The unique capabilities of this method are demonstrated by combining carbon-boron bond-forming reactions with palladium-catalyzed methylation in a tandem transformation.
Metal-Free C-O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
Bering, Luis,Jeyakumar, Kirujan,Antonchick, Andrey P.
supporting information, p. 3911 - 3914 (2018/07/22)
A catalytic, metal-free intramolecular rearrangement of benzyl phenyl ethers using nitrosonium salt as a catalyst is described. The optimized reaction conditions enabled a catalytic and metal-free Friedel-Crafts alkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel-Crafts reaction.
Nickel-catalyzed methylation of aryl halides/tosylates with methyl tosylate
Wang, Jiawang,Zhao, Jianhong,Gong, Hegui
supporting information, p. 10180 - 10183 (2017/09/23)
This work describes the cross-electrophile methylation of aryl bromides and aryl tosylates with methyl tosylate. The mild reaction conditions allow effective methylation of a wide set of heteroaryl electrophiles and dimethylation of dibromoarenes.
