- Ligand- and Counterion-Assisted Phenol O-Arylation with TMP-Iodonium(III) Acetates
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High reactivity of trimethoxyphenyl (TMP)-iodonium(III) acetate for phenol O-arylation was achieved. It was first determined that the TMP ligand and acetate anion cooperatively enhance the electrophilic reactivity toward phenol oxygen atoms. The proposed method provides access to various diaryl ethers in significantly higher yields than the previously reported techniques. Various functional groups, including aliphatic alcohol, boronic ester, and sterically hindered groups, were tolerated during O-arylation, verifying the applicability of this ligand- and counterion-assisted strategy.
- Kikushima, Kotaro,Miyamoto, Naoki,Watanabe, Kazuma,Koseki, Daichi,Kita, Yasuyuki,Dohi, Toshifumi
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p. 1924 - 1928
(2022/03/27)
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- Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates
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A metal-free route for the synthesis of biarenes has been developed. The approach is based on the photoextrusion of a phosphate moiety occurring upon irradiation of biaryl- A nd triaryl phosphates. The reaction involves an exciplex as the intermediate and it is especially suitable for the preparation of electron-rich biarenes.
- Qrareya, Hisham,Meazza, Lorenzo,Protti, Stefano,Fagnoni, Maurizio
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supporting information
p. 3008 - 3014
(2021/01/18)
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- One-pot two-step stannylation/Stille homocoupling of aryl bromides and iodides under solvent-free conditions
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A new highly efficient solvent-free method for aryl bromide (iodide) homocoupling comprising the use of Pd(OAc)2/PCy3 system in the presence of CsF is suitable for substrates bearing functional groups not tolerant to lithium-, magnesium-, zincorganic reagents and strong bases.
- Gribanov, Pavel S.,Golenko, Yulia D.,Topchiy, Maxim A.,Philippova, Anna N.,Kirilenko, Nikita Yu.,Krivoshchapov, Nikolai V.,Sterligov, Grigorii K.,Asachenko, Andrey F.,Bermeshev, Maxim V.,Nechaev, Mikhail S.
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p. 323 - 325
(2018/05/30)
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- Miyaura Borylation and One-Pot Two-Step Homocoupling of Aryl Chlorides and Bromides under Solvent-Free Conditions
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Solvent-free protocols for Miyaura borylation and the one-pot, two-step homocoupling of aryl halides are reported for the first time. Bis(dibenzylideneacetone)palladium(0) [Pd(dba)2] is an optimal source of palladium for Miyaura borylation, while for one-pot two-step homocoupling palladium(II) acetate [Pd(OAc)2] gives highest yields. Aryl bromides are coupled most efficiently using the DPEphos ligand. Chlorides are coupled using XPhos. The developed protocols are robust, versatile and easily reproducible on a large scale.
- Dzhevakov, Pavel B.,Topchiy, Maxim A.,Zharkova, Daria A.,Morozov, Oleg S.,Asachenko, Andrey F.,Nechaev, Mikhail S.
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p. 977 - 983
(2016/04/05)
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- A mild carbon-boron bond formation from diaryliodonium salts
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The direct metal-free borylation of diaryliodonium salts with diboron reagents is now demonstrated to be a feasible process toward formation of aryl boronic esters without any additive or catalysts, and it can be extended to a two-step C-C coupling of both aryl groups of the initial diaryliodonium reagent.
- Miralles,Romero,Fernández,Mu?iz
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p. 14068 - 14071
(2015/09/15)
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- Clay encapsulated Cu(OH)x promoted homocoupling of arylboronic acids: An efficient and eco-friendly protocol
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Cu(OH)x has been encapsulated over montmorillonite-KSF by simple ologomeric deposition strategy. The resulting catalyst has been employed for selective homocoupling of arylboronic acids under ambient conditions without requirement of any ligand or base. This catalyst is easy to recover and shows excellent reusability without losing its activity. Techniques like XRD, SEM, TPR, IR, BET surface area measurement and XPS were used to characterize the catalyst. The present method promises for the simple and clean homocoupling of arylboronic acids.
- Dar, Bashir Ahmad,Singh, Snehil,Pandey, Nalini,Singh,Sharma, Priti,Lazar, Anish,Sharma, Meena,Vishwakarma, Ram A.,Singh, Baldev
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p. 232 - 238
(2014/01/06)
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- Ligand-free highly effective iron/copper co-catalyzed formation of dimeric aryl ethers or sulfides
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Highly selective coupling of diiodoarenes with phenols or phenthiols can be performed by using a low-cost, benign character and readily available Fe/Cu catalytic system in the absence of ligands. It is noteworthy that the desired dimeric aryl ethers or sulfides could be obtained in high yields by coupling between diiodoarenes and phenols, or diphenols with aryl iodides. The Royal Society of Chemistry 2011.
- Qu, Xiaoming,Li, Tingyi,Zhu, Yan,Sun, Peng,Yang, Hailong,Mao, Jincheng
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supporting information; experimental part
p. 5043 - 5046
(2011/08/22)
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- Pd/TEMPO-catalyzed electrooxidative synthesis of biaryls from arylboronic acids or arylboronic esters
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A facile electrooxidative method for synthesizing biaryls from arylboronic acids or arylboronic esters is described. In the presence of a catalytic amount of Pd(OAc)2 and TEMPO, the electrooxidation of arylboronic acids or arylboronates gave the corresponding biaryls in moderate to excellent yields.
- Mitsudo, Koichi,Shiraga, Takuya,Kagen, Daisuke,Shi, Deqing,Becker, James Y.,Tanaka, Hideo
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supporting information; experimental part
p. 8384 - 8388
(2009/12/24)
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- Electrooxidative homo-coupling of arylboronic acids catalyzed by electrogenerated cationic palladium catalysts
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An electrochemical method for generating cationic palladium complexes was integrated into an electrooxidative homo-coupling of arylboronic acids. In the presence of a catalytic amount of TEMPO, the homo-coupling reaction proceeded efficiently under argon to afford symmetric biaryls.
- Mitsudo, Koichi,Shiraga, Takuya,Tanaka, Hideo
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scheme or table
p. 6593 - 6595
(2009/04/06)
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- Oxidative dimerization: Pd(II) catalysis in the presence of oxygen using aqueous media
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Reported herein is a method for the formation of symmetric biaryls and dienes via oxidative dimerization of aryl and alkenyl boronic acids. These conditions utilized Pd(II) catalysts under an oxygen atmosphere with water as the solvent. The use of phase transfer catalysts promoted efficient and mild syntheses of a wide range of materials.
- Parrish, Jay P.,Jung, Young C.,Floyd, Ryan J.,Jung, Kyung Woon
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p. 7899 - 7902
(2007/10/03)
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- Bis(cyclopentadienyliron)arene Complexes: A new route to the synthesis and functionalization of polyaromatic ethers
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A new development in the chemistry of arenes activated toward SNAr reactions by the cyclopentadienyliron (FeCp+) moiety is presented in this work. A class of diiron complexes of diphenoxybenzenes was prepared in a highly efficient and very mild fashion. Dihydroxy aromatic compounds served as dinucleophiles, allowing for the formation of the diiron complexes. This could be achieved in either a one or two step procedure. A wide variety of dinucleophiles were incorporated into this study, as well as a number of FeCp+ activated arenes. It is shown that these reactions are not inhibited by bulky substituents on either the dinucleophiles or activated arenes. The diiron complexes themselves could also undergo SNAr reactions, provided that the complexed arenes contained a chlorine substituent. This allowed for the functionalization of the complexes with species that could not be introduced directly in their syntheses. The carbon nucleophiles generated from ethyl cyanoacetate or (phenylsulfonyl)acetonitrile could be attached to the complexed ethers in this manner. The FeCp+ moieties were removed easily by photolytic demetalation which allowed for the recovery of a wide range of functionalized diphenoxybenzenes. This methodology is advantageous over all those previously reported and should be a practical route to the synthesis of aromatic ethers.
- Abd-El-Aziz, Alaa S.,Schriemer, David C.,De Denus, Christine R.
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p. 374 - 384
(2008/10/08)
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- The palladium(II) / carbon monoxide-mediated biaryl formation from aryltellurium trihalides
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Treatment of aryltellurium trihalides (ArTeX3: Ar=Ph, 4-BrC6H4, 4-MeC6H4, 4-MeOC6H4, 4-BuOC6H4, 4-PhOC6H4, 2-naphthyl; X=Cl,Br) with a palladium(II) salt in acetonitrile at 25 deg C affords, in good yields (29-78 percent), the corresponding biaryls (ArAr) either in the atmosphere or under 1 atm CO.The presence of CO accelerates this aromatic coupling significantly to produce some active palladium carbonyl species, the formation of which was confirmed by IR spectroscopy of Li2PdCl4 in acetonitrile solution under CO; a strong sharp absorption and a weaker sharp one appeared at 2140 and 1908 cm-1, respectively, attributable to the ν(CO) of the (Pd-CO) species.Treatment with alkali after reaction was essential to producing the biaryls.
- Takahashi, Hidetaka,Ohe, Kouichi,Uemura, Sakae,Sugita, Nobuyuki
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p. 227 - 234
(2007/10/02)
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