- A Foldamer-Based Organocatalyst for Direct Arylations of Unactivated Arenes
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It was demonstrated that a simple yet well-folded pyridone dimer, possessing two convergently aligned electron-rich O atoms for potassium binding, can serve as a highly efficient organocatalyst for catalyzing transition-metal-free arylations of unactivated aromatic C-H bonds with aryl halides in the presence of t-BuOK. A wide range of aryl iodides could be cross-coupled with unactivated arenes in moderate to excellent yields. The experiments using radical-scavenging reagents confirm the participation of radicals in this catalytic transformation.
- Zhao, Huaiqing,Shen, Jie,Ren, Changliang,Zeng, Wei,Zeng, Huaqiang
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Read Online
- A highly efficient and recyclable NiCl2(dppp)/PEG-400 system for Suzuki-Miyaura reaction of aryl chlorides with arylboronic acids
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NiCl2(dppp) in PEG-400 is shown to be a highly efficient catalyst for Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids. The reaction could be conducted at 100 °C using K3PO4 as base, yielding a variety of biaryls in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and NiCl2(dppp)/PEG-400 system could be easily recycled and reused up to five times without significant loss of activity. Our system not only avoids the use of easily volatile and toxic dioxane or toluene as a solvent but also solves the basic problem of nickel catalyst reuse.
- Liao, Yang,Yang, Weisen,Wei, Ting,Cai, Mingzhong
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Read Online
- Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone
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Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.
- Bracher, Franz,Jourjine, Ilya A. P.,Krau?, Jürgen,Zeisel, Lukas
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supporting information
p. 2668 - 2679
(2021/11/30)
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- Desulfonative Suzuki–Miyaura Coupling of Sulfonyl Fluorides
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Sulfonyl fluorides have emerged as powerful “click” electrophiles to access sulfonylated derivatives. Yet, they are relatively inert towards C?C bond forming transformations, notably under transition-metal catalysis. Here, we describe conditions under which aryl sulfonyl fluorides act as electrophiles for the Pd-catalyzed Suzuki–Miyaura cross-coupling. This desulfonative cross-coupling occurs selectively in the absence of base and, unusually, even in the presence of strong acids. Divergent one-step syntheses of two analogues of bioactive compounds showcase the expanded reactivity of sulfonyl fluorides to encompass both S?Nu and C?C bond formation. Mechanistic experiments and DFT calculations suggest oxidative addition occurs at the C?S bond followed by desulfonation to form a Pd-F intermediate that facilitates transmetalation.
- Bahadori, Maryam,Brykczyńska, Daria,Chatelain, Paul,Moran, Joseph,Muller, Cyprien,Rowley, Christopher N.,Sau, Abhijit
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p. 25307 - 25312
(2021/10/25)
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- Preparation of Functionalized Diorganomagnesium Reagents in Toluene via Bromine or Iodine/Magnesium-Exchange Reactions
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A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents are prepared in toluene within 10 to 120 minutes between 78 C and 25 C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2Mg (R = sBu, Mes). Highly sensitive functional groups, such as triazene or nitro, are tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arene and alkene derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides.
- Desaintjean, Alexandre,Danton, Fanny,Knochel, Paul
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supporting information
p. 4461 - 4476
(2021/08/13)
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- NaH-mediated direct C-H arylation in the presence of 1,10-phenanthroline
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Transition-metal-free coupling of haloarenes with unactivated arenes has been developed in the presence of NaH and 1,10-phenanthroline. Various haloarenes bearing methyl, methoxy, halogen (fluoride, chloride, and bromide), cyano, trifluoromethyl, ester, and amide groups can be cross-coupled with unactivated arenes, or heteroarenes in this reaction.
- Nozawa-Kumada, Kanako,Iwakawa, Yuki,Onuma, So,Shigeno, Masanori,Kondo, Yoshinori
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supporting information
p. 7773 - 7776
(2020/07/27)
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- 6-Arylphenanthridines from Aryl o-Biaryl Ketones with 1,1,1,3,3,3-Hexamethyldisilazane and Molecular Iodine
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Warming treatment of aryl o-biaryl ketones with 1,1,1,3,3,3-hexamethyldisilazane in the presence of Sc(OTf)3 in toluene, followed by the reaction with molecular iodine and K2CO3 in a mixture of THF and methanol at 60 °C gave the corresponding 6-arylphenanthridines in good to moderate yields. The present reaction is a one-pot method for the preparation of 6-arylphenanthridines from aryl o-biaryl ketones through the cyclization of imino-nitrogen-centered radicals that were generated from N-iodo aryl o-biaryl ketimines formed from the reaction of aryl biaryl ketimines with molecular iodine.
- Kobayashi, Eiji,Kishi, Atsushi,Togo, Hideo
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p. 7335 - 7347
(2019/11/22)
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- Preparation of Polyfunctional Arylzinc Organometallics in Toluene by Halogen/Zinc Exchange Reactions
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A wide range of polyfunctional diaryl- and diheteroarylzinc species were prepared in toluene within 10 min to 5 h through an I/Zn or Br/Zn exchange reaction using bimetallic reagents of the general formula R′2Zn?2 LiOR (R′=sBu, tBu, pTol). Highly sensitive functional groups, such as a triazine, a ketone, an aldehyde, or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of a plethora of functionalized (hetero)arenes after quenching with various electrophiles. Insight into the constitution and reactivity of these bimetallic mixtures revealed the formation of highly active lithium diorganodialkoxyzincates of type [R′2Zn(OR)2Li2].
- Balkenhohl, Moritz,Ziegler, Dorothée S.,Desaintjean, Alexandre,Bole, Leonie J.,Kennedy, Alan R.,Hevia, Eva,Knochel, Paul
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supporting information
p. 12898 - 12902
(2019/07/31)
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- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
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A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
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supporting information
p. 6445 - 6448
(2019/06/07)
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- Controllable Rh(III)-Catalyzed C-H Arylation and Dealcoholization: Access to Biphenyl-2-carbonitriles and Biphenyl-2-carbimidates
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A controllable Rh(III)-catalyzed C-H arylation and dealcoholization of benzimidates with arylboronic esters was developed, delivering various biphenyl-2-carbonitriles and biphenyl-2-carbimidates by simply tuning the reaction conditions. This approach features high efficiency, good functional group tolerance, and easy operation. It also provides an alternative pathway to thoroughly exploit the directing group in transition-metal-catalyzed C-H activations.
- Jiang, Bo,Wu, Songxiao,Zeng, Jing,Yang, Xiaobo
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p. 6573 - 6577
(2018/10/09)
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- Integrating Organic Lewis Acid and Redox Catalysis: The Phenalenyl Cation in Dual Role
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In recent years, merging different types of catalysis in a single pot has drawn considerable attention and these catalytic processes have mainly relied upon metals. However, development of a completely metal free approach integrating organic redox and organic Lewis acidic property into a single system has been missing in the current literature. This study establishes that a redox active phenalenyl cation can activate one of the substrates by single electron transfer process while the same can activate the other substrate by a donor-acceptor type interaction using its Lewis acidity. This approach has successfully achieved light and metal-free catalytic C-H functionalization of unactivated arenes at ambient temperature (39 entries, including core moiety of a top-selling molecule boscalid), an economically attractive alternative to the rare metal-based multicatalysts process. A tandem approach involving trapping of reaction intermediates, spectroscopy along with density functional theory calculations unravels the dual role of phenalenyl cation.
- Ahmed, Jasimuddin,Chakraborty, Soumi,Jose, Anex,Sreejyothi,Mandal, Swadhin K.
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supporting information
p. 8330 - 8339
(2018/06/19)
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- Urea-based organocatalyst catalyzed direct C–H bond arylations of unactivated arenes
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A simple 1,3-diethylurea was demonstrated to catalyze transition-metal-free arylations of unactivated aromatic C–H bonds with aryl iodides in the presence of t-BuOK. A broad range of aryl iodides with different arenes could couple in moderate to excellent yields. The mechanistic experiment results indicated that the radical is involved in this transformation.
- Zhao, Huaiqing,Xu, Xiangwen,Wu, Wei,Zhang, Wei,Zhang, Yunxian
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- A Robust and Broadly Applicable Cobalt-Catalyzed Cross-Coupling of Functionalized Bench-Stable Organozinc Pivalates with Unsaturated Halides
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We report a robust and broadly applicable CoCl2-catalyzed cross-coupling between functionalized aryl and heteroaryl zinc pivalates and various electron-poor aryl and heteroaryl halides (X=Cl, Br, I). Couplings with (E)- or (Z)-bromo- or iodo-alkenes proceed with retention of configuration. Also, alkynyl bromides react with arylzinc pivalates providing arylated alkynes.
- Hammann, Jeffrey M.,Lutter, Ferdinand H.,Haas, Diana,Knochel, Paul
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supporting information
p. 1082 - 1086
(2017/01/18)
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- Manganese-Catalyzed Cross-Coupling of Aryl Halides and Grignard Reagents by a Radical Mechanism
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The substrate scope and the mechanism have been investigated for the MnCl2-catalyzed cross-coupling reaction between aryl halides and Grignard reagents. The transformation proceeds rapidly and in good yield when the aryl halide component is an aryl chloride containing a cyano or an ester group in the para position or a cyano group in the ortho position. A range of other substituents gave no conversion of the aryl halide or led to the formation of side products. A broader scope was observed for the Grignard reagents, where a variety of alkyl- and arylmagnesium chlorides participated in the coupling. Two radical-clock experiments were carried out, and in both cases an intermediate aryl radical was successfully trapped. The cross-coupling reaction is therefore believed to proceed by an SRN1 mechanism, with a triorganomanganate complex serving as the most likely nucleophile and single-electron donor. Other mechanistic scenarios were excluded based on the substrate scope of the aryl halide.
- Antonacci, Giuseppe,Ahlburg, Andreas,Fristrup, Peter,Norrby, Per-Ola,Madsen, Robert
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p. 4758 - 4764
(2017/09/07)
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- A reusable heterogeneous catalyst without leaking palladium for highly-efficient Suzuki-Miyaura reaction in pure water under air
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Herein, we report a heterogenous catalyst (Pd@FSM) by immobilization of a novel Pd2+ sensor as promoter over mesoporous silica. Pd@FSM with a high palladium loading of ca. 11 mg g-1 exhibited superior catalytic activity for Suzuki-Miyaura cross-couplings and a catalyst loading of 0.05 mol% is typically sufficient to achieve excellent reaction yields. Notably, the reaction is typically carried out in water without removing atmospheric oxygen. The catalyst is conveniently recycled and remains highly active even after being recycled 5 times. During this process, loss of palladium from the solid support of the catalyst is negligible. Furthermore, the catalyst can be stored in air for at least three months without loss of its catalytic activity. This work provides a new approach to developing heterogeneous palladium catalysts by combing materials and fluorescent sensors.
- Cai, Qi,Liang, Gaosheng,Xu, Yufang,Qian, Xuhong,Zhu, Weiping
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p. 60996 - 61000
(2016/07/12)
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- Photoinduced C-H direct arylation of unactivated arenes
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Two general protocols have been developed for the photoinduced, metal-free direct arylation of unactivated arenes with aryl iodide. Both methods gave good to excellent yields for most substrates. Notably, the C-F bond in method A and the C-F, C-Cl, and C-Br bonds in method B could survive the arylation reaction. These methods offered excellent options for syntheses of biaryls.
- Kan, Jian,Huang, Shijun,Zhao, Huaiqing,Lin, Jin,Su, Weiping
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p. 1329 - 1333
(2015/08/06)
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- Synthesis, characterization and X-ray structures of N-heterocyclic carbene palladium complexes based on calix[4]arenes: Highly efficient catalysts towards Suzuki-Miyaura cross-coupling reactions
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A new series of calix[4]arene supported N-heterocyclic carbene palladium complexes were developed and fully characterized. A mono-substituted calix[4]arene was prepared through conventional procedures, following with the attachment of imidazolyl derivative groups to compose the precursors of novel NHCs ligands. Undergoing the alkylation with n-butylbromide and corresponding metallation with palladium and pyridine, original complexes were obtained. After a full characterization in solution and solid state, the evaluation of catalytic activity was taken out in Suzuki-Miyaura cross-coupling reactions, which revealed good performances.
- Ren, Hui,Xu, Yong,Jeanneau, Erwann,Bonnamour, Isabelle,Tu, Tao,Darbost, Ulrich
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p. 2829 - 2837
(2014/04/17)
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- The transition-metal-catalyst-free oxidative homocoupling of organomanganese reagents prepared by the insertion of magnesium into organic halides in the presence of MnCl2·2LiCl
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Organomanganese reagents were prepared by the insertion of magnesium into aryl halides in the presence of MnCl2·2LiCl. These organomanganese reagents smoothly undergo 1,2-addition, acylation, and Pd-catalyzed cross-coupling with various electrophiles. Especially, the oxidative homocoupling of organomanganese reagents was completed in one pot without an additional transition-metal catalyst.
- Peng, Zhihua,Li, Na,Sun, Xinyang,Wang, Fang,Xu, Lanjian,Jiang, Cuiyu,Song, Linhua,Yan, Zi-Feng
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p. 7800 - 7809
(2014/12/10)
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- Efficient one-pot cross-coupling of two aryl halides by stannylation/stille reaction in water under microwave irradiation
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A simple and highly efficient one-pot approach has been developed for the Pd(PPh3)4-catalyzed cross-coupling of two different aryl or heteroaryl bromides/iodides. This method involves the combined use of microwave irradiation and water as a single solvent to achieve sequential stannylation and Stille cross-coupling reactions, which allows rapid access to a wide variety of biaryls in good to high yields. Furthermore, utilizing this step-economical protocol, 2,5-dibromopyridine was iteratively diarylated and the Boscalid intermediate was also synthesized in a one-pot manner. Copyright
- Tan, Xin,Zhou, Zi Jie,Zhang, Jia Xin,Duan, Xin Hong
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p. 5153 - 5157
(2014/09/29)
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- Green and scalable procedure for extremely fast ligandless Suzuki-Miyaura cross-coupling reactions in aqueous IPA using solid-supported Pd in continuous flow
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An environmentally friendly continuous-flow protocol for the Suzuki coupling of boronic acids and aryl halides under ligand-free conditions using solid-supported Pd is presented. The process described herein uses very simple reaction conditions and equipment setup and can be readily scaled up to provide multigram quantities of products containing low levels of residual Pd.
- Mateos, Carlos,Rincón, Juan A.,Martín-Hidalgo, Beatriz,Villanueva, José
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p. 3701 - 3705
(2014/06/23)
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- Novel N-biphenyl-2-ylmethyl 2-methoxyphenylpiperazinylalkanamides as 5-HT7R antagonists for the treatment of depression
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5-HT7 receptor (5-HT7R) is a promising target for the treatment of depression and neuropathic pain. 5-HT7R antagonists exhibited antidepressant effects, while the agonists produced strong anti-hyperalgesic effects. In our efforts to discover selective 5-HT 7R antagonists or agonists, N-biphenylylmethyl 2- methoxyphenylpiperazinylalkanamides 1 were designed, synthesized, and biologically evaluated against 5-HT7R. Among the synthesized compounds, N-2′-chlorobiphenylylmethyl 2- methoxyphenylpiperazinylpentanamide 1-8 showed the best binding affinity with a Ki value of 8.69 nM and it was verified as a novel antagonist according to functional assays. The compound 1-8 was very selective over 5-HT1DR, 5-HT2AR, 5-HT3R, 5-HT5AR and 5-HT6R and moderately selective over 5-HT1AR, 5-HT1BR and 5-HT2CR. The novel 5-HT7R antagonist 1-8 exhibited an antidepressant effect at a dose of 25 mg/kg in the forced swimming test in mice and showed a U-shaped dose-response curve which typically appears in 5-HT7R antagonists such as SB-269970 and lurasidone.
- Kim, Youngjae,Tae, Jinsung,Lee, Kangho,Rhim, Hyewhon,Choo, Il Han,Cho, Heeyeong,Park, Woo-Kyu,Keum, Gyochang,Choo, Hyunah
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p. 4587 - 4596
(2014/10/15)
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- Direct C-H arylations of unactivated arenes catalyzed by amido-functionalized imidazolium salts
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The synthesis of biaryls from unactivated arenes and a broad range of aryl bromides and chlorides via the direct C-H functionalization can be efficiently performed with the aid of amido-functionalized imidazolium salts as organocatalysts. This method avoids the use of toxic transition metal catalysts and organometallic reagents.
- Ghosh, Debalina,Lee, Jhen-Yi,Liu, Chian-Yu,Chiang, Yen-Hsin,Lee, Hon Man
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supporting information
p. 406 - 410
(2014/05/20)
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- Zwitterionic palladium complexes: Room-temperature Suzuki-Miyaura cross-coupling of sterically hindered substrates in an aqueous medium
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A series of new imidazolium chlorides were straightforwardly prepared from the reactions between chloroacetone and imidazole derivatives. Deprotonation of the methylene proton next to the ketone group in these salts by pyridine led to the formation of a monodentate ligand that coordinated to palladium, readily forming zwitterionic anionic palladium pyridine complexes bearing a formal positive charge on the ligand ancillary. The pyridine ligand in the zwitterionic complexes can be facilely replaced by phosphine ligands. Seven of these new complexes were successfully characterized by X-ray crystallography. The zwitterionic phosphine complexes were highly efficient in catalyzing room-temperature Suzuki-Miyaura reactions between sterically hindered aryl chlorides and arylboronic acids in an aqueous medium.
- Lee, Jhen-Yi,Ghosh, Dabalina,Lee, Jing-Yi,Wu, Shih-Sheng,Hu, Ching-Han,Liu, Shuang-De,Lee, Hon Man
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p. 6481 - 6492
(2015/02/19)
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- Metal-free directed ortho C-H iodination: Synthesis of 2'-iodobiaryl-2- carbonitriles
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Metal-free directed ortho C-H iodination of biaryl-2-carbonitriles was developed. A series of 2'-iodobiaryl-2-carbonitriles were synthesized from substituted biphenylcarbonitriles and naphthylbenzonitriles in reasonably good yields by using bis(pyridine)iodonium(I) tetrafluoroborate (IPy 2BF4, Barluenga's reagent) and HBF4· OEt2. The biaryl-2-carbonitriles are useful precursors for the synthesis of benzocyclic ketones. Metal-free directed ortho C-H iodination of biaryl-2-carbonitriles is efficiently performed in good yields by using bis(pyridine)iodonium(I) tetrafluoroborate (IPy2BF4, Barluenga's reagent) and HBF4·OEt2. Copyright
- Sarkar, Satinath,Jana, Manoranjan,Narender, Tadigoppula
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supporting information
p. 6491 - 6495
(2013/11/06)
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- Palladium-catalyzed desulfitative cross-coupling of sodium arylsulfinates with aryl bromides and chlorides: An alternative convenient synthesis of biaryls
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An alternative method for synthesis of biaryls has been developed through the Pd catalyzed desulfitative coupling reaction of sodium arylsulfinates with aryl bromides and chlorides. The procedure tolerates a variety of functional groups, such as cyano, formyl, acetyl, chloro, methoxy, trifluoromethyl and heteroaromatic unit. The desired products were obtained in moderate to excellent yields under relatively mild reaction conditions without additives, base or co-catalyst. An alternative method for synthesis of biaryls has been developed through the Pd catalyzed desulfitative coupling reaction of sodium arylsulfinates with aryl bromides and chlorides. The procedure tolerates a variety of functional groups, such as cyano, formyl, acetyl, chloro, methoxy, trifluoromethyl and heteroaromatic unit. The desired products were obtained in moderate to excellent yields under relatively mild reaction conditions without additives, base or co-catalyst. Copyright
- Zhou, Chao,Li, Yaming,Lu, Yang,Zhang, Rong,Jin, Kun,Fu, Xinmei,Duan, Chunying
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p. 1269 - 1273
(2013/11/06)
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- Novel syntheses of fluorenones via nitrile-directed palladium-catalyzed C-H and dual C-H bond activation
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Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
- Wan, Jung-Chih,Huang, Jun-Min,Jhan, Yu-Huei,Hsieh, Jen-Chieh
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supporting information
p. 2742 - 2745
(2013/07/19)
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- A macrocyclic aromatic pyridone pentamer as a highly efficient organocatalyst for the direct arylations of unactivated arenes
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A macrocyclic aromatic pyridone pentamer was shown to catalyze highly efficient transition-metal-free arylations of unactivated aromatic C-H bonds with aryl iodides and bromides in the presence of potassium tert-butoxide. The Royal Society of Chemistry.
- Zhao, Huaiqing,Shen, Jie,Guo, Juanjuan,Ye, Ruijuan,Zeng, Huaqiang
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supporting information
p. 2323 - 2325
(2013/06/26)
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- Palladium-catalyzed desulfitative arylation by C-O bond cleavage of aryl triflates with sodium arylsulfinates
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An efficient Pd-catalyzed desulfitative coupling reaction of sodium arylsulfinates as arylation reagents by C-O bond cleavage of aryl triflates was developed. With only 2 mol % of Pd(OAc)2 as catalyst and XPhos as ligand, the reaction proceeded well for a range of substrates.
- Zhou, Chao,Liu, Qingjiang,Li, Yaming,Zhang, Rong,Fu, Xinmei,Duan, Chunying
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p. 10468 - 10472
(2013/01/15)
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- An efficient suzuki-miyaura coupling of aryl sulfamates and boronic acids catalyzed by NiCl2(dppp)
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The Suzuki-Miyaura cross-coupling of aryl sulfamates and boronic acids was investigated by using [1,3-bis(diphenylphosphanyl)propane]nickel(II) chloride {NiCl2(dppp)} as the catalyst. The results showed that NiCl 2(dppp) is a highly active and general catalyst that allows effective Suzuki-Miyaura cross-coupling of aryl sulfamates with a slight excess amount of the boronic acid (1.2 equiv.) in the presence of a low catalyst loading (generally 1.0-1.5 mol-%). The method also displays broad generality not only to various aryl sulfamates, but also to an array of boronic acids. Furthermore, various functional groups are tolerated. These apparent advantages make NiCl2(dppp) a practical and reliable catalyst system for the Suzuki-Miyaura coupling of aryl sulfamates.
- Chen, Guo-Jun,Han, Fu-She
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supporting information; experimental part
p. 3575 - 3579
(2012/07/27)
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- Proline catalyzes direct C-H arylations of unactivated arenes
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Several amino acids were tested to catalyze the transition-metal-free direct C-H arylation of unactivated benzene derivatives. Among them, proline was found to be an excellent catalyst for the cross-coupling between aryl halides and unactivated arenes. The reaction presumably involves an aryl radical anion as the intermediate based on several experiments. The reaction using this catalyst system offers an option toward establishing an environmentally benign and cost-effective route to biaryls.
- Tanimoro, Kouichi,Ueno, Minoru,Takeda, Kazutaka,Kirihata, Mitsunori,Tanimori, Shinji
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p. 7844 - 7849
(2013/01/15)
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- A highly practical and reliable nickel catalyst for Suzuki-Miyaura coupling of aryl halides
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We disclose that [1,3-bis(diphenylphosphino)methane]nickel(II) chloride [NiCl2(dppp)] is a highly active, universally applicable, cheap, and stable catalyst for Suzuki-Miyaura cross-coupling reactions of aryl halides with a catalyst loading of lower than 1 mol%, and more notably, in the absence of extra supporting ligands. Under the optimized reaction conditions, a broad range of aryl bromides as well as the notoriously unreactive aryl chlorides, including activated, non-activated, deactivated, and heteroaromatic and sterically hindered substrates can be coupled smoothly with various boronic acids (47 examples, 48-98% yields). In addition, the transformation is tolerant of various functional groups such as ether, ester, ketone, aldehyde, cyano, and unprotected amino and hydroxy groups. Finally, the potential utilization of the methodology was further demonstrated by the gram-scale synthesis of several core structures of commercialized antihypertensive drugs and fungicides. Thus, the combination of high activity, broad applicability, cheapness, and high stability of NiCl2(dppp) presented in this work constitutes one of the few prominent catalysts which allow for practical and reliable construction of biaryls and heterobiaryls with structural diversity from readily available aryl halides and boronic acids. Copyright
- Zhao, Yu-Long,Li, You,Li, Shui-Ming,Zhou, Yi-Guo,Sun, Feng-Yi,Gao, Lian-Xun,Han, Fu-She
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supporting information; experimental part
p. 1543 - 1550
(2011/08/07)
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- UV promoted phenanthridine syntheses from oxime carbonate derived iminyl radicals
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Oxime carbonates were found to be excellent precursors for the clean and direct generation of iminyl radicals under UV irradiation. Suitably functionalised iminyls underwent cyclisations yielding various phenanthridines and also substituted quinolines and
- McBurney, Roy T.,Slawin, Alexandra M. Z.,Smart, Laura A.,Yu, Yanping,Walton, John C.
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p. 7974 - 7976
(2011/08/08)
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- Tert-butoxide-mediated arylation of benzene with aryl halides in the presence of a catalytic 1,10-phenanthroline derivative
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Sodium tert-butoxide mediates the coupling of aryl halides with benzene derivatives without the aid of transition metal catalysts but with a catalytic 1,10-phenanthroline derivative.
- Shirakawa, Eiji,Itoh, Ken-Ichi,Higashino, Tomohiro,Hayashi, Tamio
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supporting information; experimental part
p. 15537 - 15539
(2010/12/30)
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- [Pd(Cl)2(P(NC5H10)(C6H 11)2)2] - A highly effective and extremely versatile palladium-based negishi catalyst that efficiently and reliably operates at low catalyst loadings
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[Pd(Cl)2(P(NC5H10)-(C6H 11)2]2] (1) has been prepared in quantitative yield by reacting commercially available [Pd(cod)(Cl)2] (cod = cyclooctadiene) with readily prepared 1-(dicyclohexylphosphanyl)piperidine in toluene under N2 within a few minutes at room temperature. Complex 1 has proved to be an excellent Negishi catalyst, capable of quantitatively coupling a wide variety of electronically activated, non-activated, deactivated, sterically hindered, heterocyclic, and functionalized aryl bromides with various (also heterocyclic) arylzinc reagents, typically within a few minutes at 100°C in the presence of just 0.01 mol% of catalyst. Aryl bromides containing nitro, nitrile, ether, ester, hydroxy, carbonyl, and carboxyl groups, as well as acetais, lactones, amides, anilines, alkenes, carboxylic acids, acetic acids, and pyridines and pyrimidines, have been successfully used as coupling partners. Furthermore, electronic and steric variations are tolerated in both reaction partners. Experimental observations strongly indicate that a molecular mechanism is operative.
- Bolliger, Jeanne L.,Frech, Christian M.
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experimental part
p. 11072 - 11081
(2010/11/16)
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- Copper-catalyzed synthesis of phenanthridine derivatives under an oxygen atmosphere starting from biaryl-2-carbonitriles and grignard reagents
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A copper-catalyzed synthesis of phenanthridine derivatives was developed starting from biaryl-2-carbonitriles and Grignard reagents. The present transformation is carried out by a sequence of nucleophilic addition of Grignard reagents to biaryl-2-carbonitriles to form N-H imines and their Cu-catalyzed C-N bond formation on the aromatic C-H bond, where molecular oxygen is a prerequisite to achieve the catalytic process.
- Zhang, Line,Ang, Gim Yean,Chiba, Shunsuke
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supporting information; experimental part
p. 3682 - 3685
(2010/10/20)
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- Palladium/tris(tert-butyl)phosphine-catalyzed Suzuki cross-couplings in the presence of water
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Dipalladiumtris(dibenzylideneacetone)/tris(tert-butyl)phosphonium tetrafluoroborate/potassium fluoride dihydrate [Pd2(dba) 3/[HP(t-Bu)3]BF4/KF·2H2O] serves as a mild, robust, and user-friendly method for the efficient Suzuki cross-coupling of a diverse array of aryl and heteroaryl halides with aryl- and heteroarylboronic acids.
- Lou, Sha,Fu, Gregory C.
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supporting information; experimental part
p. 2081 - 2084
(2010/10/20)
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- A convenient synthesis of benzonitriles via electrophilic cyanation with N-cyanobenzimidazole
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(Chemical Equation Presented) Couplings: N-Cyanobenzimidazole has been used in the synthesis of aryl- and heteroarylnitriles from the corresponding Grignard reagents (see scheme). This electrophilic cyanation is further extended to the synthesis of 2-cyano1,1'-biaryls through a domino Grignard-coupling/ cyanation strategy.
- Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 4725 - 4728
(2010/07/04)
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- A recyclable triethylammonium ion-tagged diphenylphosphine palladium complex for the Suzuki-Miyaura reaction in ionic liquids
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Suzuki-Miyaura reactions of aryl bromides and arylboronic acids proceed in good to excellent yields in a pyrrolidinium ionic liquid by using a preformed air stable and easily handled triethylammonium-tagged diphenylphosphine palladium(ii) complex (2). The reaction requires short reaction times and mild temperature conditions and does not show any tendency towards the formation of palladium black. After extraction of the product, the catalyst containing ionic liquid phase is easily recycled for 6 times, with no significant loss of catalytic activity.
- Lombardo, Marco,Chiarucci, Michel,Trombini, Claudio
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experimental part
p. 574 - 579
(2010/04/23)
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- New mixed Li/Mg and Li/Mg/Zn amides for the chemoselectlve metallation of arenes and heteroarenes
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New mixed Li/Mg and Li/Mg/Zn amides have been synthesized starting from readily prepared secondary amines. They allow a highly chemoselective directed magnesiation or zincation of various polyfunctional aromatics and heteroaromatics. The kinetic basicity, solubility and stability of these new bases have been compared with those of the corresponding 2,2,6,6- tetramethylpiperamide-derived bases. Wiley-VCH Verlag GmbH & Co. KGaA.
- Rohbogner, Christoph J.,Wunderlich, Stefan H.,Clososki, Giuliano C.,Knochel, Paul
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experimental part
p. 1781 - 1795
(2009/09/05)
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- Radical catalysis of kumada cross-coupling reactions using functionalized grignard reagents
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(Chemical Equation Presented) Palladium, radically different: A wide range of polyfunctional aryl- and heteroarylmagnesium reagents undergo fast Kumada cross-couplings (see scheme) with functionalized aryl bromides in the presence of a palladium catalyst and an alkyl iodide as additive. These reactions proceed by a radical pathway.
- Manolikakes, Georg,Knochel, Paul
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supporting information; experimental part
p. 205 - 209
(2009/04/10)
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- Convenient preparation of polyfunctional aryl magnesium reagents by a direct magnesium insertion in the presence of LiCl
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(Chemical Equation Presented) In the footsteps of Victor Grignard: The simple LiCl-mediated insertion of magnesium into aryl chlorides and bromides at moderate temperatures leads to functionalized organomagnesium reagents (see scheme). An unprecedented range of functional groups may be present in the substrates (e.g. CN, CO2R, OTs, OBoc; Ts=p-toluenesulfonyl, Boc=tert-butylcarbonyloxy).
- Piller, Fabian M.,Appukkuttan, Prasad,Gavryushin, Andrei,Helm, Matthew,Knochel, Paul
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supporting information; experimental part
p. 6802 - 6806
(2009/04/06)
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- Arylzinc species by microwave assisted Grignard formation-transmetallation sequence: Application in the Negishi coupling
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Arylmagnesium species can be efficiently generated from magnesium turnings and aryl chlorides or aryl bromides under dielectric heating conditions. Subsequent microwave assisted transmetallation using ZnCl2-TMEDA afforded the corresponding arylzinc reagents. A sequential microwave assisted arylmagnesium formation-transmetallation-Negishi coupling protocol suitable for automated multiple parallel synthesis has been developed.
- Mutule, Ilga,Suna, Edgars
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p. 11168 - 11176
(2007/10/03)
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- Microwave-assisted Negishi and Kumada cross-coupling reactions of aryl chlorides
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Rapid Pd or Ni-catalyzed microwave-accelerated Negishi and Kumada cross-coupling reactions of aryl chlorides in solution and on solid phase are reported.
- Walla, Peter,Kappe, C. Oliver
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p. 564 - 565
(2007/10/03)
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- New chemical synthesis of functionalized arylzinc compounds from aromatic or thienyl bromides under mild conditions using a simple cobalt catalyst and zinc dust
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A new chemical method for the preparation of arylzinc intermediates is described in acetonitrile, on the basis of the activation of aryl bromides by low-valent cobalt species arising from the reduction of cobalt halide by zinc dust. This procedure allows for the synthesis of a variety of functionalized aryl- and thienylzinc species in good to excellent yields. The versatility and the simplicity of that original method represent an alternative to most known procedures.
- Fillon, Hyacinthe,Gosmini, Corinne,Perichon, Jacques
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p. 3867 - 3870
(2007/10/03)
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- Synthesis of unsymmetrical biaryls by electroreductive cobalt-catalyzed cross-coupling of aryl halides
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The consumable anode process allows the electrochemical cross-coupling reaction between various functionalized aromatic halides (iodides, bromides and chlorides) in the presence of cobalt halides as catalyst in a mixed solvent acetonitrile/pyridine (9:1). A great variety of unsymmetrical biaryls are obtained in moderate to excellent yields.
- Gomes, Paulo,Fillon, Hyacinthe,Gosmini, Corinne,Labbé, Eric,Périchon, Jacques
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p. 8417 - 8424
(2007/10/03)
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- Method for producing unsymmetrically substituted biphenyls
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PCT No. PCT/IB97/00266 Sec. 371 Date Sep. 29, 1998 Sec. 102(e) Date Sep. 29, 1998 PCT Filed Feb. 24, 1997 PCT Pub. No. WO97/30970 PCT Pub. Date Aug. 28, 1997The invention concerns a method for the production of unsymmetrically substituted cyanobiphenyls by the slow addition of an aryl Grignard compound to an optionally substituted bromobenzonitrile in the presence of a palladium complex catalyst.
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- Biphenyl-substituted quinoline derivatives
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Compounds of the formula wherein X, R1, R2, R3, R4, R5, R6, A, B, D and E are as defined herein. These compounds inhibit the action of angiotensin II and are useful, therefore, for example, as antihypertensive agents.
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- Manganese-catalyzed substitution of activated aryl halides (X = Cl, Br and F) and aryl ethers by organomagnesium reagents
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In the presence of manganese chloride (10%), Grignard reagents readily react in THF with aryl bromides, chlorides and even fluorides, as well as aryl methyl ethers bearing in the ortho- or para-position an electron withdrawing activating group (CN, CH=NR, oxazoline). Aryl and N- or S- alkylmagnesium halides have been used successfully. The reaction is performed under mild conditions (0 °C to room temperature, 30 minutes to 24 hours) and leads to cross-coupling products in good yields.
- Cahiez, Gerard,Lepifre, Franck,Ramiandrasoa, Parfait
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p. 2138 - 2144
(2007/10/03)
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- Quinoxaline biphenyl angiotensin II inhibitors
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Angiotensin II inhibition is exhibited by STR1 wherein: X is --CH2 -- or O; R is hydrogen, alkyl, aryl, cycloalkyl, aralkyl, or cycloalkylalkyl; R1 and R2 are each independently O or absent; R3 is hydrogen, alkyl, alkenyl, alkoxy, cycloalkyl, aryl, aralkyl, cycloalkylalkyl, halo, haloalkyl, or haloalkoxy; R4 is hydrogen, alkyl, alkenyl, alkoxy, aryl, cycloalkyl, aralkyl, cycloalkylalkyl, --R8 --OH, or --R8 CO2 R9 ; and the remaining symbols are as defined in the specification.
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- Method for producing an asymmetric biaryl derivative
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A method for producing an asymmetric biaryl derivative which comprises dehalogenocoupling halogenated benzene derivatives, wherein a bromobenzene derivative of the formula: STR1 wherein R is a lower alkyl group or a lower alkoxy group, which is attached at the 3- or 4-position, and a 2-chlorobenzene derivative of the formula: STR2 wherein R' is a cyano group or an alkoxycarbonyl group, are reacted in pyridine in the presence of triphenylphosphine, an anhydrous nickel compound and a reducing metal to obtain an asymmetric biaryl derivative of the formula: STR3 wherein R and R' are as defined above, and R is attached at the 3- or 4-position.
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