13524-78-2Relevant articles and documents
Diarylation of alkenes by a Cu-catalyzed migratory insertion/cross-coupling cascade
You, Wei,Brown, M. Kevin
, p. 14730 - 14733 (2014)
A strategy for the catalytic diarylation of alkenes is presented. The method involves the migratory insertion of alkenes into an Ar-Cu complex to generate a new C(sp3)-Cu complex, which subsequently undergoes reaction with an aryl iodide to constitute a vicinal diarylation of an alkene. The method provides access to benzofuran- and indoline-containing products. Furthermore, highly diastereoselective examples are presented, allowing access to complex, stereochemically rich structures from simple alkene starting materials.
Selective Oxygen Atom Insertion into an Aryl-Palladium Bond
Behnia, Ava,Boyle, Paul D.,Blacquiere, Johanna M.,Puddephatt, Richard J.
, p. 2645 - 2654 (2016)
The chemistry of a palladium(II) complex containing both an alkyl- and an aryl-palladium bond is reported. The reaction of [Pd(CH2CMe2C6H4)(MesN=CHCH=NMes)] with bromine or iodine leads to reductive elimination of 1,1-dimethylcyclobutabenzene with formation of [PdX2(MesN=CHCH=NMes)] (X = Br, I). However, the reaction with hydrogen peroxide gives [Pd(CH2CMe2C6H4O)(MesN=CHCH=NMes)] by overall oxygen atom insertion into the aryl-palladium rather than the alkyl-palladium bond. This complex [Pd(CH2CMe2C6H4O)(MesN=CHCH=NMes)] reacts with bromine, iodine, or hydrogen peroxide to give 3,3-dimethyl-2,3-dihydrobenzofuran and the corresponding complex [PdX2(MesN=CHCH=NMes)]. The mechanisms of reaction and basis for selectivity are discussed. The results support the view that oxygen atom insertion is a mechanistically viable pathway for selective catalytic oxidation of hydrocarbons by the green oxidant hydrogen peroxide.
Pincer-plus-one ligands in self-assembly with palladium(ii): a molecular square and a molecular tetrahedron
Behnia, Ava,Boyle, Paul D.,Fard, Mahmood A.,Blacquiere, Johanna M.,Puddephatt, Richard J.
, p. 19485 - 19490 (2016)
The combination of a palladium(ii) precursor with a diimine-phenol ligand and an oxidant (H2O2 or O2) under different conditions has, serendipitously, given both a molecular square and a molecular tetrahedron by self-assembly of building blocks comprising palladium(ii) centres coordinated to the oxidised forms of the ligand.
Iridium-catalyzed enantioselective intramolecular hydroarylation of allylic aryl ethers devoid of a directing group on the aryl group
Kusaka, Satoshi,Ohmura, Toshimichi,Suginome, Michinori
, p. 13542 - 13545 (2021/12/23)
Although intramolecular hydroarylation is an attractive transformation of allylic aryl ethers, it has suffered from narrow substrate scope. We herein describe Ir/(S)-DTBM-SEGPHOS-catalyzed intramolecular hydroarylation of allylic aryl ethers. The reaction
Aerobic C-C and C-O bond formation reactions mediated by high-valent nickel species
Gómez, Laura,Mirica, Liviu M.,Planas, Oriol,Rath, Nigam P.,Ribas, Xavi,Smith, Sofia M.
, p. 10366 - 10372 (2019/11/20)
Nickel complexes have been widely employed as catalysts in C-C and C-heteroatom bond formation reactions. While Ni(0), Ni(i), and Ni(ii) intermediates are most relevant in these transformations, recently Ni(iii) and Ni(iv) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(ii) and Ni(iii) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(ii) complexes with various other oxidants led to exclusive C-C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to formation of appreciable amounts of C-O bond formation products, especially for the Ni(ii) complex supported by an asymmetric pyridinophane ligand containing one tosyl N-substituent. Moreover, cryo-ESI-MS studies support the formation of several high-valent Ni species as key intermediates in this uncommon Ni-mediated oxygenase-type chemistry.
Iridium-Catalyzed C(sp3)?H Addition of Methyl Ethers across Intramolecular Carbon–Carbon Double Bonds Giving 2,3-Dihydrobenzofurans
Ohmura, Toshimichi,Kusaka, Satoshi,Torigoe, Takeru,Suginome, Michinori
, p. 4448 - 4453 (2019/09/16)
Intramolecular addition of an O-methyl C(sp3)?H bond across a carbon-carbon double bond occurs in the iridium-catalyzed reaction of methyl 2-(propen-2-yl)phenyl ethers. The Ir/(S)-DTBM-SEGPHOS catalyst promotes the reaction efficiently in toluene at 110–135 °C to afford 3,3-dimethyl-2,3-dihydrobenzofurans. Enantioselective C(sp3)?H addition is achieved in the reaction of methyl 2-(1-siloxyethenyl)phenyl ethers, affording enantioenriched 3-hydroxy-2,3-dihydrobenzofuran derivatives with up to 96% ee. (Figure presented.).
Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane
Hokamp, Tobias,Dewanji, Abhishek,Lübbesmeyer, Maximilian,Mück-Lichtenfeld, Christian,Würthwein, Ernst-Ulrich,Studer, Armido
supporting information, p. 13275 - 13278 (2017/10/09)
A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.
Exploring SmBr2-, SmI2-, and YbI2-mediated reactions assisted by microwave irradiation
Dahlen, Anders,Prasad, Edamana,Flowers II, Robert A.,Hilmersson, Goeran
, p. 3279 - 3284 (2007/10/03)
The use of microwave heating in lanthanide(II) halide (LnX2 = SmBr2, SmI2, and YbI2) mediated reduction and coupling reactions has been investigated for a variety of functional groups including α,β-unsaturated esters, aldehydes, ketones, imines, and alkyl halides. Good to quantitative transformations were obtained within a few minutes without the addition of any co-solvents, such as hexamethyl phosphoramide (HMPA). The redox potential of YbI2 in tetrahydrofuran (THF) has been determined as -1.02± 0.05 V (versus Ag/AgNO3) by cyclic voltammetry. A large selectivity difference in various reactions was observed depending on the redox potential of the LnX2 reagent. The more powerful reductant, SmBr2, afforded mainly pinacol-coupling products of ketones whereas the weaker reductant YbI2 afforded mainly reduction products. The results indicate that the reducing power of LnX 2 has a large impact on not only the pinacol coupling/reduction product ratio of ketones but also on other substrates in which there are competing coupling and reduction reactions. The use of in situ generated LnX2 has also been explored and proven useful in many of these reactions.
Diastereoselective intramolecular SmI2-H2O-amine mediated couplings
Dahlen, Anders,Petersson, Annika,Hilmersson, Goeran
, p. 2423 - 2426 (2007/10/03)
The effectiveness of SmI2-H2O-amine mixture for intramolecular couplings was discussed. Diastereoselectivities in the coupling of O-cyclohexanyliodophenol derivatives were provided into heterocycles. The amount of coupled product improved significantly as SmI2, the substrate and amine were premixed followed by a gradual addition of water.
Selectivity in the tandem cyclization - Carboxylation reaction of unsaturated haloaryl ethers catalyzed by electrogenerated nickel complexes
Olivero,Du?ach
, p. 1885 - 1891 (2007/10/03)
The electrochemical reduction of a series of 2-haloaryl ethers containing allyl and propargyl groups under CO2 allows the synthesis of benzofuranacetic acid derivatives. This novel intramolecular cyclization- carboxylation reaction is carried out in single-compartment cells and is catalyzed by [Ni(cyclam)Br2].
