cas 47230-38-6, DIETHYL BIPHENYL-4,4'-DICARBOXYLATE

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Tandem Mn–I Exchange and Homocoupling Processes Mediated by a Synergistically Operative Lithium Manganate
Pairing lithium and manganese(II) to form lithium manganate [Li2Mn(CH2SiMe3)4] enables the efficient direct Mn–I exchange of aryliodides, affording transient (aryl)lithium manganate intermediates which in turn undergo spontaneous C?C homocoupling at room temperature to furnish symmetrical (bis)aryls in good yields under mild reaction conditions. The combination of EPR with X-ray crystallographic studies has revealed the mixed Li/Mn constitution of the organometallic intermediates involved in these reactions, including the homocoupling step which had previously been thought to occur via a single-metal Mn aryl species. These studies show Li and Mn working together in a synergistic manner to facilitate both the Mn–I exchange and the C?C bond-forming steps. Both steps are carefully synchronized, with the concomitant generation of the alkyliodide ICH2SiMe3 during the Mn–I exchange being essential to the aryl homocoupling process, wherein it serves as an in situ generated oxidant.
Uzelac, Marina,Mastropierro, Pasquale,de Tullio, Marco,Borilovic, Ivana,Tarrés, Màrius,Kennedy, Alan R.,Aromí, Guillem,Hevia, Eva
supporting information
p. 3247 - 3253
(2020/12/11)

Sustainable Synthesis of Biaryls Using Silica Supported Ferrocene Appended N-Heterocyclic Carbene-Palladium Complex
Abstract: A novel silica supported ferrocene appended N-heterocyclic carbene-palladium complex (SilFemBenzNHC@Pd) has been prepared and characterized by using fourier transform infrared (FT-IR), fourier transform Raman (FT-Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and energy dispersive X-ray analysis (EDX). This novel complex served as a robust heterogeneous catalyst for the synthesis of biaryls via homocoupling of aryl boronic acids under base-free conditions in water. Recyclability experiments were executed successfully for six successive runs. Graphic Abstract: [Figure not available: see fulltext.]
Khanapure, Sharanabasappa,Pore, Dattaprasad,Jagadale, Megha,Patil, Vaishali,Rashinkar, Gajanan
p. 2237 - 2249
(2021/01/11)

Spatial anion control on palladium for mild C-H arylation of arenes
C-H arylation of arenes without the use of directing groups is a challenge, even for simple molecules, such as benzene. We describe spatial anion control as a concept for the design of catalytic sites for C-H bond activation, thereby enabling nondirected C-H arylation of arenes at ambient temperature. The mild conditions enable late-stage structural diversification of biologically relevant small molecules, and site-selectivity complementary to that obtained with other methods of arene functionalization can be achieved. These results reveal the potential of spatial anion control in transition-metal catalysis for the functionalization of C-H bonds under mild conditions.
Dhankhar, Jyoti,González-Fernández, Elisa,Dong, Chao-Chen,Mukhopadhyay, Tufan K.,Linden, Anthony,?ori?, Ilija
p. 19040 - 19046
(2020/11/13)

Palladium-Catalyzed Silylation of Aryl Chlorides with Bulky Dialkoxydisilanes
Arylsilanes bearing a bulky alkoxy group on the silicon were synthesized from aryl chlorides and dialkoxydisilanes under reaction conditions utilizing SingaCycle-A3 as a palladium precatalyst and lithium benzoate in wet DMA. This report proposes the first direct and catalytic method for introducing tert -butoxy- or 1-adamantyloxysilyl groups onto various aryl moieties through the silylation reaction.
Fukui, Keitaro,Saito, Hayate,Shimokawa, Jun,Yorimitsu, Hideki
p. 1328 - 1332
(2020/08/13)

Metal-Reductant-Free Electrochemical Nickel-Catalyzed Couplings of Aryl and Alkyl Bromides in Acetonitrile
While reductive cross-electrochemical coupling is an attractive approach for the synthesis of complex molecules at both small and large scale, two barriers for large-scale applications have remained: the use of stoichiometric metal reductants and a need for amide solvents. In this communication, new conditions that address these challenges are reported. The nickel-catalyzed reductive cross-coupling of aryl bromides with alkyl bromides can be conducted in a divided electrochemical cell using acetonitrile as the solvent and diisopropylamine as the sacrificial reductant to afford coupling products in synthetically useful yields (22-80%). Additionally, the use of a combination of the ligands 4,4′,4″-tri-tert-butyl-2,2′:6′,2′-terpyridine and 4,4′-di-tert-butyl-2,2′-bipyridine is essential to achieve high yields.
Perkins, Robert J.,Hughes, Alexander J.,Weix, Daniel J.,Hansen, Eric C.
supporting information
p. 1746 - 1751
(2019/08/20)

One-pot two-step stannylation/Stille homocoupling of aryl bromides and iodides under solvent-free conditions
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.
p. 323 - 325
(2018/05/30)

Nickel-Catalyzed Electrochemical Reductive Homocouplings of Aryl and Heteroaryl Halides: A Useful Route to Symmetrical Biaryls
Due to their widespread presence in functional materials and pharmaceuticals, biaryls are of fundamental importance in organic chemistry. Methods for the synthesis of symmetrical biaryls generally involve both metallic reduction and transition-metal catalysis. In this work, we show that electroreduction can also constitute a very relevant way to achieve the nickel-catalyzed reductive synthesis of symmetrical biaryl compounds. Therefore, it is demonstrated that both aryl and heteroaryl halides undergo reductive coupling to furnish the corresponding symmetrical biaryls in fair to excellent yields. Reactions are performed under very mild conditions thus ensuring important functional group tolerance.
Rahil, Rima,Sengmany, Stéphane,Le Gall, Erwan,Léonel, Eric
p. 146 - 154
(2017/09/28)

Gold(i)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes
Gold(i)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes are described. This redox neutral strategy offers an efficient approach to diverse biaryls, vinyl arenes and arylacetylenes. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the in situ formation of Ph3PAuIR (R = aryl, vinyl and alkynyl) species which is crucial for the activation of aryldiazonium salts.
Akram, Manjur O.,Shinde, Popat S.,Chintawar, Chetan C.,Patil, Nitin T.
supporting information
p. 2865 - 2869
(2018/05/03)

Synthesis of dendrimer-type viologen and its use in Pd-mediated homocoupling of aryl halides
Dendrimer-type viologen (V2+.D.) was prepared from mesitylene and 4.4′-bipyridyl. Electroreduction of V2+.D. gave the corresponding quinoid (V0.D.), which promoted Pd-catalyzed homocoupling of aryl bromides Ar-Br to give the corresponding biaryls Ar-Ar in moderate to good yields.
Kuroboshi, Manabu,Kojima, Atsuki,Tanaka, Hideo
p. 2132 - 2140
(2017/11/21)

Electrochemical Nickel Catalysis for Sp2-Sp3 Cross-Electrophile Coupling Reactions of Unactivated Alkyl Halides
A constant-current electrochemical method for reducing catalytic nickel complexes in sp2-sp3 cross-electrophile coupling reactions has been developed. The electrochemical reduction provides reliable nickel catalyst activation and turnover and offers a tunable parameter for reaction optimization, in contrast to more standard activated metal powder reductants. The electrochemical reactions give yields (i.e., 51-86%) and selectivities as high or superior to those using metal powder reductants and provide access to a wider substrate scope.
Perkins, Robert J.,Pedro, Dylan J.,Hansen, Eric C.
supporting information
p. 3755 - 3758
(2017/07/26)

Graphene Oxide: An Efficient Acid Catalyst for the Construction of Esters from Acids and Alcohols
Graphene oxide was found to be an efficient and reusable acid catalyst for the esterification reaction. A wide range of aliphatic and aromatic acids and alcohols were compatible with the standard conditions and afforded the corresponding products in good yields. The heterogeneous catalyst can be easily recovered and recycled in dichloro-ethane solvent with good catalytic activity.
Chen, Zhengwang,Wen, Yuelu,Fu, Yejuan,Chen, Hai,Ye, Min,Luo, Guotian
supporting information
p. 981 - 985
(2017/05/05)

Cobalt-Catalyzed Oxidative Homocoupling of Arylzinc Species
A novel procedure for the synthesis of functionalized symmetrical biaryl compounds is described. The reaction proceeds via the oxidative homocoupling of arylzinc species formed by cobalt catalysis in the presence of air or p-benzoquinone depending on the nature of the functional group.
Bourne-Branchu, Yann,Moncomble, Aurélien,Corpet, Martin,Danoun, Gregory,Gosmini, Corinne
p. 3352 - 3356
(2016/09/12)

Ligand- and Base-Free Access to Diverse Biaryls by the Reductive Coupling of Diaryliodonium Salts
A ligand- and base-free, Pd-catalyzed protocol to access a wide range of symmetrical and unsymmetrical biaryls from stable diaryliodonium salts was developed. The reaction involved the use of an effective and recyclable Pd/polyethylene glycol-400 catalyst system to harness the aryl moieties of two diaryliodonium salts; the ensuing biaryls may be utilized to synthesize an array of useful compounds, including 5-aryluracils, carbazoles, chromenones, fluorenones, phenathridines, and boscalid analogues.
Arun,Reddy, P. O. Venkataramana,Pilania, Meenakshi,Kumar, Dalip
supporting information
p. 2096 - 2100
(2016/05/09)

Single electron transfer-induced coupling of alkynylzinc reagents with aryl and alkenyl iodides
Alkynylzinc reagents were found to undergo coupling with aryl and alkenyl iodides to give arylalkynes and alkenylalkynes without the aid of transition metals. The coupling reaction proceeds through a single electron transfer mechanism, where a substoichiometric amount of a phosphine works as an indispensable activator.
Okura, Keisho,Kawashima, Hitomi,Tamakuni, Fumiko,Nishida, Naoya,Shirakawa, Eiji
supporting information
p. 14019 - 14022
(2016/12/09)

A Copper-Based Metal-Organic Framework Acts as a Bifunctional Catalyst for the Homocoupling of Arylboronic Acids and Epoxidation of Olefins
A copper(I)-based metal-organic framework ({[Cu2Br2(pypz)]na.nH2O} (Cu-Br-MOF) [pypz=bis[3,5-dimethyl-4-(4'-pyridyl)pyrazol-1-yl] methane] has been synthesized by using an elongated and flexible bridging ligand. The structure analysis reveals that each pypz ligand acts as a tritopic ligand connected to two Cu2Br2 dimeric units, forming a one-dimensional zig-zag chain, and these chains further connected by a Cu2Br2 unit, give a two-dimensional framework on the bc-plane. In the Cu2Br2 dimeric unit, the copper ions are four coordinated, thereby possessing a tetrahedral geometry; this proves to be an excellent heterogeneous catalyst for the aerobic homocoupling of arylboronic acids under mild reaction conditions. This method requires only 3 mol % of catalyst and it does not require any base or oxidant-compared to other conventional (Cu, Pd, Fe, and Au) catalysts-for the transformation of arylboronic acids in very good yields (98 %). The shape and size selectivity of the catalyst in the homocoupling was investigated. The use of the catalyst was further extended to the epoxidation of olefins. Moreover, the catalyst can be easily separated by simple filtration and reused efficiently up to 5 cycles without major loss of reactivity.
Parshamoni, Srinivasulu,Telangae, Jyothi,Sanda, Suresh,Konar, Sanjit
p. 540 - 547
(2016/03/12)

Imino-N-heterocyclic carbene palladium(ii) complex-catalyzed direct arylation of electron-deficient fluoroarenes with "on and off" chelating effect assistance
An imino-N-heterocyclic carbene palladium(II) complex with a bulky substituted group on the imino nitrogen was used to catalyze the direct arylation of electron-deficient fluoroarenes with aryl halides. A series of electron-poor substrates and aryl bromides could be coupled in good to excellent yields with satisfactory position selectivity (20 examples, up to 93%). These arylations could proceed at a relatively low temperature (80 °C, 20 examples, up to 95%) with mono-N-protected amino acid assistance. Some of them even gained higher yields than those at high temperature (110 °C). Otherwise, some aryl iodides can forge cross-coupling products in yields of nearly 30% under the optimized conditions. The rate profiles for arylation of electron-poor arenes were measured in the presence of the imino-N-heterocyclic carbene palladium(II) complex or Pd(OAc)2 as the catalyst, which showed that the former could keep catalytic activity for a longer time. Computational studies indicated that the imino nitrogen in the imino-N-heterocyclic carbene ligand can detach from and attach to the central metal in the catalytic cycle. Thus, the coordination site could be protected, and this effect may be responsible for decreasing the rate of palladium black formation.
Zhou, Quan,Wang, Ya-Nong,Guo, Xu-Qing,Zhu, Xiao-Han,Li, Zhi-Ming,Hou, Xiu-Feng
p. 1021 - 1028
(2015/03/31)

Diquat derivatives, a precursor of organic reductant
Electroreduction of diquat triflate gave a potent organic reductant, which promoted reductive dimerization of aryl bromides in the presence of palladium catalysts to give the corresponding biaryl compounds.
Kuroboshi, Manabu,Kondo, Takashi,Tanaka, Hideo
p. 723 - 729
(2015/03/04)

Development and Application of a Multielectron-Accepting Organic Oxidant for the Catalytic Transition-Metal-Free Oxidative Homocoupling of Grignard Reagents in Air
Heptafluorotolyl-substituted perfluorocyclopentene acts as a four-electron oxidant for the homocoupling of Grignard reagents. It can also be used for catalytic homocoupling with a low catalyst loading (up to 2 mol %) in the presence of atmospheric oxygen. The organocatalytic cycle involves the generation of an organic radical and a perfluorocyclopentadienyl anion.
Korenaga, Toshinobu,Nitatori, Kaoru,Muraoka, Hiroki,Ogawa, Satoshi,Shimada, Kazuaki
supporting information
p. 5500 - 5503
(2015/11/18)

Palladium-catalyzed, ligand-free Suzuki reaction in water using aryl fluorosulfates
Aryl fluorosulfates were prepared by a simple method and employed as coupling partners in the Suzuki-Miyaura reaction. The cross-coupling reactions were performed in water under air at room temperature without ligands or additives such as surfactants or phase-transfer reagents and proceeded smoothly to give excellent yields. Aryl fluorosulfates could also be used as alternatives to halides or triflates in other coupling reactions.
Liang, Qiaobin,Xing, Ping,Huang, Zuogang,Dong, Jiajia,Sharpless, K. Barry,Li, Xiaoxian,Jiang, Biao
supporting information
p. 1942 - 1945
(2015/04/27)

Catalyst activation, deactivation, and degradation in palladium-mediated negishi cross-coupling reactions
Pd-mediated Negishi cross-coupling reactions were studied by a combination of kinetic measurements, electrospray-ionization (ESI) mass spectrometry, 31P NMR and UV/Vis spectroscopy. The kinetic measurements point to a rate-determining oxidative addition. Surprisingly, this step seems to involve not only the Pd catalyst and the aryl halide substrate, but also the organozinc reagent. In this context, the ESI-mass spectrometric observation of heterobimetallic Pd-Zn complexes [L2PdZnR]+ (L=S-PHOS, R=Bu, Ph, Bn) is particularly revealing. The inferred presence of these and related neutral complexes with a direct Pd-Zn interaction in solution explains how the organozinc reagent can modulate the reactivity of the Pd catalyst. Previous theoretical calculations by Gonzlez-Prez et al. (Organometallics 2012, 31, 2053) suggest that the complexation by the organozinc reagent lowers the activity of the Pd catalyst. Presumably, a similar effect also causes the rate decrease observed upon addition of ZnBr2. In contrast, added LiBr apparently counteracts the formation of Pd-Zn complexes and restores the high activity of the Pd catalyst. At longer reaction times, deactivation processes due to degradation of the S-PHOS ligand and aggregation of the Pd catalyst come into play, thus further contributing to the appreciable complexity of the title reaction. Catalytic complexity: The Pd catalyst used in Negishi cross-coupling reactions shows an unexpected heterogeneity and complexity. Among the various species observed in solution, heterobimetallic Pd-Zn complexes are of particular interest (see figure). These species also seem key to understanding the kinetics of Negishi cross-coupling reactions. S-PHOS=2-dicyclohexylphosphino-2,6-dimethoxybiphenyl.
B?ck, Katharina,Feil, Julia E.,Karaghiosoff, Konstantin,Koszinowski, Konrad
supporting information
p. 5548 - 5560
(2015/03/30)

Quinonediimine-induced oxidative coupling of organomagnesium reagents
N,N′-Diphenyl-p-benzoquinonediimine, a redox-active unit of polyaniline, efficiently induced the oxidative homocoupling of various aryl- and vinylmagnesium reagents in suppressing the side reactions, such as 1,2- or 1,4-addition reaction. Copyright
Amaya, Toru,Suzuki, Riyo,Hirao, Toshikazu
p. 653 - 656
(2014/01/23)

Unmasked acyl anion equivalent from acid chloride with indium: Reversed-polarity synthesis of unsymmetric aryl aryl and alkenyl aryl ketone through palladium-catalyzed cross-coupling reaction
A reversed-polarity synthetic method of a range of unsymmetric aryl aryl and alkenyl aryl ketones has been developed through Pd-catalyzed cross-coupling reaction of acylindium reagents generated in situ from easily available acid chlorides and indium with various electrophiles such as aryl iodide and triflate and alkenyl triflate.
Lee, Dohyung,Ryu, Taekyu,Park, Youngchul,Lee, Phil Ho
supporting information
p. 1144 - 1147
(2014/03/21)

Viologen as catalytic organic reductant: Electro-reductive dimerization of aryl bromides in a Pd/viologen double mediatory system
Viologen can be used as an in situ recyclable organic reductant. Pd-catalyzed electrochemical reductive coupling of aryl bromides was performed by using a catalytic amount of viologen to afford the corresponding biaryls in good to moderate yields.
Kuroboshi, Manabu,Shiba, Takuya,Tanaka, Hideo
p. 3666 - 3668
(2013/07/05)

Oxidative coupling reactions of grignard reagents with nitrous oxide
Catalysis with laughing gas: N2O in combination with transition-metal catalysts allow the oxidative homo- and cross-coupling of Grignard reagents. The reactions can be performed under mild conditions despite the inert character of N2O. Copyright
Kiefer, Gregor,Jeanbourquin, Loic,Severin, Kay
supporting information
p. 6302 - 6305
(2013/07/19)

The role of magnetic nanoparticles (MNP) as reducing agents in an MNP-supported Pd-catalyst for the reductive homocoupling of aryl halides
A palladium pincer catalyst grafted onto the surface of magnetic nanoparticles (MNPs) has been developed. This material effectively catalyzes the reductive homocoupling of various aryl halide substrates, with the MNP support acting as the reducing agent. The catalyst can be recycled up to five times in the absence of additional reducing agent to give almost quantitative yields of biaryl homocoupling products. After the reducing power of the MNP has been depleted, the supported Pd complex remains an effective catalyst for Suzuki-Miyaura cross-coupling.
Zheng, Jie,Lin, Shengyue,Jiang, Bi-Wang,Marder, Todd B.,Yang, Zhen
supporting information; scheme or table
p. 138 - 144
(2012/03/07)

Cobalt-catalyzed vinylation of aromatic halides using β-halostyrene: Experimental and DFT studies
A new protocol for the direct cobalt-catalyzed vinylation of aryl halides using β-halostyrene has been developed in order to form functionalized stilbenes. A variety of aromatic halides featuring different reactive group were employed. This method proceeded smoothly with a total retention of the double bond configuration in the presence of triphenylphosphine as ligand. Preliminary DFT calculations rationnalize these results and proposed a reaction pathway in agreement with the experimental conditions. This procedure offers a new route to the stereoselective synthesis of stilbenes.
Moncomble, Aurelien,Floch, Pascal Le,Lledos, Agusti,Gosmini, Corinne
experimental part
p. 5056 - 5062
(2012/07/14)

Organozinc chemistry enabled by micellar catalysis. Palladium-catalyzed cross-couplings between alkyl and aryl bromides in water at room temperature
Negishi-like cross-couplings between (functionalized) alkyl and aryl bromides are described. Despite the fact that organozinc reagents are intolerant of water, their formation as well as their use in an aqueous micellar environment is discussed herein. Each component of this complex series of events leading up to C-C bond formation has an important role which has been determined insofar as the type of zinc, amine ligand, surfactant, and palladium catalyst are concerned. In particular, the nature of the surfactant has been found to be crucial in order to obtain synthetically useful results involving highly reactive, moisture-sensitive organometallics. Neither organic solvent nor heat is required for these cross-couplings to occur; just add water.
Duplais, Christophe,Krasovskiy, Arkady,Lipshutz, Bruce H.
scheme or table
p. 6090 - 6097
(2012/01/04)

Ligand effects on Negishi couplings of alkenyl halides
Negishi couplings at olefinic centers do not always occur with the anticipated maintenance of stereochemistry. The source of erosion has been traced to the ligand, and a modified method has been developed that solves the stereochemical issue and significantly improves yields of Negishi couplings in general.
Krasovskiy, Arkady,Lipshutz, Bruce H.
supporting information; experimental part
p. 3818 - 3821
(2011/10/01)

Homodimeric bis-quaternary heterocyclic ammonium salts as potent acetyl- and butyrylcholinesterase inhibitors: A systematic investigation of the influence of linker and cationic heads over affinity and selectivity
A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium) or sterically hindered aliphatic (quinuclidinium) nitrogen rings kept at an appropriate distance by lipophilic rigid or semirigid linkers. Many homodimeric QASs showed AChE and BChE inhibitory potency in the nanomolar range along with a low enzymatic selectivity. Computational studies on AChE, BChE, and ChoK allowed identification of the key molecular determinants for high affinity and selectivity over either one of the three enzymes and guided the design of a hybrid bis-QAS (56) exhibiting the highest AChE affinity (IC50 = 15 nM) and selectivity over BChE and ChoK (SI = 50 and 562, respectively) and a promising pharmacological potential in myasthenia gravis and neuromuscular blockade.
Conejo-García, Ana,Pisani, Leonardo,Del Carmen Nú?ez, Maria,Catto, Marco,Nicolotti, Orazio,Leonetti, Francesco,Campos, Joaquín M.,Gallo, Miguel A.,Espinosa, Antonio,Carotti, Angelo
experimental part
p. 2627 - 2645
(2011/06/21)

Cobalt-xantphos-catalyzed, LiCl-mediated preparation of arylzinc reagents from aryl iodides, bromides, and chlorides
A cobalt-Xantphos-catalyzed, LiCl-mediated system has been developed for the direct and expedient preparation of arylzinc reagents in THF from the corresponding aryl iodides, bromides, and chlorides. Owing to the use of THF as a versatile solvent, the thus-formed arylzinc reagents displayed a high degree of compatibility with a variety of conventional as well as newly emerging metal-catalyzed cross-coupling reactions.
Jin, Meng-Yi,Yoshikai, Naohiko
experimental part
p. 1972 - 1978
(2011/05/19)

Coupling/cyclization of 1,6-enynes with aryl halides: An efficient and general route for the synthesis of functionalized hexahydroindole and hexahydrobenzofuran derivatives
An efficient and general route for the synthesis of functionalized hexahydroindole and hexahydrobenzofuran derivatives has been developed via the palladium-catalyzed domino coupling/cyclization reaction of 1,6-enynes and aryl halides. The results indicate
Meng, Tuan-Jie,Hu, Yi-Min,Sun, Yong-Jie,Zhu, Tao,Wang, Shaowu
experimental part
p. 8648 - 8653
(2010/11/19)

Synthesis and characterization of novel unnatural bichalcones
Five bichalcones (5-1 ～ 5-4, 9) were prepared by the reaction of biphenyl-4,4′-dicarbaldehyde (4) and 4,4′-dioxybenzaldehyde (8) with the respective acetophenone analogs via Claisen-Schmidt condensation and were then fully identified by 1H-NMR, 13C-NMR and mass analyses.
Gurung, Santosh K.,Kim, Soo Bae,Park, Haeil
p. 1919 - 1926
(2012/01/05)

Synthesis of primary aryl amines through a copper-assisted aromatic substitution reaction with sodium azide
(Figure Presented) A method is presented by which aryl halides and azides are converted to the corresponding primary aryl amines with copper(I) and sodium azide.
Markiewicz, John T.,Wiest, Olaf,Helquist, Paul
supporting information; scheme or table
p. 4887 - 4890
(2010/10/19)

Regioselectivity in the addition of grignard reagents to bis(2-benzothiazolyl) ketone: C- vs. O-alkylation using aryl grignard reagents
The reaction between bis(2-benzothiazolyl) ketone (1) and a series of ring-substituted phenyl Grignard reagents gives, in considerable amount, the unexpected O-alkylation product derived from the attack of the Grignard reagent to thecarbonyl oxygen atom,
Boga, Carla,Micheletti, Gabriele
experimental part
p. 5659 - 5665
(2010/12/25)

Palladium catalyzed reductive homocoupling reactions of aromatic halides in dimethyl sulfoxide (DMSO) solution
Biaryls were obtained in good to excellent yields from the palladium catalyzed reductive homocoupling reactions of various aryl iodides and bromides in dimethyl sulfoxide (DMSO) solution without the need for any additional reducing reagents. Pd(dppf)Cl2 is the most effective among the screened palladium catalysts for the homocoupling reactions. Fluorides, carbonates, acetates and hydroxides can be used as bases at promoting the palladium catalyzed reductive homocoupling of aryl halides in DMSO solution. X-ray photoelectron spectroscopic (XPS) analysis shows that the oxidative Pd2+(dppf) species can be reduced into the Pd0(dppf) active species by solvent DMSO molecules to furnish the catalytic cycle, indicating that DMSO plays a dual role as both solvent and reducing reagent. A plausible reaction mechanism has been discussed. Elimination of additional reducing reagents will not only reduce the reaction operation cost, but will also simplify the product separation and purification.
Qi, Chenze,Sun, Xudong,Lu, Cuiyun,Yang, Jinzhi,Du, Yijun,Wu, Huajiang,Zhang, Xian-Man
experimental part
p. 2912 - 2916
(2009/10/23)

Transition-metal-free oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents with TEMPO
Oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents by using commercially available TEMPO as an organic oxidant is described. These coupling reactions occur highly efficiently without the presence of any transition metal. Georg Thieme Verlag Stuttgart.
Maji, Modhu Sudan,Studer, Armido
experimental part
p. 2467 - 2470
(2010/01/14)

Cobalt-catalyzed formation of symmetrical biaryls and its mechanism
A method for cobalt-catalyzed formation of symmetrical biaryls and mechanism used for the formation, were reported. The study involved a new cobalt-catalyzed homo-coupling reaction in which cobalt was used with manganese dust as reducing agent. It was observed that the presence of allylchloride significantly reduced the amount of reduction compounds without modifying kinetics of the reactions and the reaction remained un-affected by the presence of air as oxidant. It was also found that no-reactions occurred in DMF, THF, and toluene in the presence of pyridine as co-solvent at room temperature, which indicated that MeCN acted as a ligand of the cobalt active species. The coupling process can be extended to less reactive aryl chlorides by changing some experimental conditions. DFT calculations revealed that the involvement of a CoI/CoIII couple was realistic in the case of 1,3-diazadienes as ligands.
Moncomble, Aurelien,Floch, Pascal Le,Gosmini, Corinne
supporting information; experimental part
p. 4770 - 4774
(2009/12/05)

Thieme journal awardees - Where are they now? on cobalt-catalyzed biaryl coupling reactions
An operationally simple biaryl coupling reaction has been developed. The underlying domino process involves in situ Grignard formation from aryl bromides and subsequent homocoupling with catalytic CoCl2 and 1 bar synthetic air as terminal oxidant. Georg Thieme Verlag Stuttgart.
Mayer, Matthias,Czaplik, Waldemar Maximilian,Jacobi Von Wangelin, Axel
body text
p. 2919 - 2923
(2010/01/21)

Homocoupling of arylboronic acids catalyzed by 1,10-phenanthroline-ligated copper complexes in air
The efficient homocoupling of arylboronic acids was achieved by using the catalytic combination of inexpensive copper salts and 1,10-phenanthroline as aligand. The homocoupling reaction proceeds at ambient temperature in air without any additives such as base or oxidant. This method tolerates various substituents on the arylboronic acids such as halogens, carbonyls, and a nitro group. As a result, 25 symmetrical biaryls were obtained from readily available arylboronic acids in 19-92% isolated yields. A binuclear (μ- hydroxido)copper complex is assumed as the catalytically active species, which undergoes efficient transmetalation with arylboronic acids to produce dinuclear arylcopper complexes. The binuclear structure is assumed to be essential for the bimetallic reductive elimination of biaryls as well as the oxidative restoration of the catalyst. Wiley-VCH Verlag GmbH & Co, KGaA.
Kirai, Naohiro,Yamamoto, Yoshihiko
experimental part
p. 1864 - 1867
(2009/08/17)

Pd/TEMPO-catalyzed electrooxidative synthesis of biaryls from arylboronic acids or arylboronic esters
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
supporting information; experimental part
p. 8384 - 8388
(2009/12/24)

Rh-catalyzed Negishi alkyl-aryl cross-coupling leading to α- or β-phosphoryl-substituted alkylarenes
The catalytic cross-coupling between ArZnX and ICH2(CH 2)nP(O)(OEt)2 (n = 0-3) has been investigated to determine the utility of the Rh catalyst during the alkyl-aryl cross-coupling and to develop a new syntheti
Takahashi, Hideki,Inagaki, Shinya,Yoshii, Naoko,Gao, Fuxing,Nishihara, Yasushi,Takagi, Kentaro
supporting information; body text
p. 2794 - 2797
(2009/09/08)

Efficient cobalt-catalyzed formation of unsymmetrical biaryl compounds and its application in the synthesis of a sartan intermediate
(Chemical Equation Presented) No prior preparation of the organometallic reagent is required in a cobalt-catalyzed coupling of two different aryl halides under mild conditions (see scheme). A broad spectrum of valuable biaryl compounds can be prepared in this way. Not only may a variety of reactive substituents be present, but heteroaryl halides and aryl triflates are also suitable substrates. DMF = N,N-dimethylformamide, FG = functional group.
Amatore, Muriel,Gosmini, Corinne
supporting information; experimental part
p. 2089 - 2092
(2009/02/06)

METHOD FOR THE PREPARATION OF A COMPOUND OF THE GENERAL FORMULA R1-R1 AND/OR R1-R2 USING HOMO AND HETERO COUPLING REACTIONS
The present application relates to a method for the preparation of a compound of the general formula R1-R2 (I) and/or R1-R1 (II) comprising providing a compound of the general formula R1dM1Am.zM4Zn (III) or R1R2M1R3kAm.xM4Zn (IV) or R1M1R2R3kM2Am.xM4Zn (V) or R1M3R2M1.xM4Zn (VI) and reacting this compound III-VI with a quinone to produce a compound of the general formula (I) or (II) or a mixture of compounds (I) and (II). The coupling reaction can be used to prepare homo and/or hetero coupling products from well known starting materials using a quinone as redox reagent. The quinone may be recycled from the reaction.
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(2010/11/29)

Manganese- or iron-catalyzed homocoupling of grignard reagents using atmospheric oxygen as an oxidant
Atmospheric oxygen was used for the first time as an oxidant in metal-catalyzed homocoupling of Grignard reagents. These manganese- or iron-catalyzed reactions are efficient, cheap, and eco-friendly. They are applicable to the large-scale synthesis of symmetrical conjugated compounds. Copyright
Cahiez, Gerard,Moyeux, Alban,Buendia, Julien,Duplais, Christophe
p. 13788 - 13789
(2008/04/11)

Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions using allylindium generated in situ from allyl acetates, indium, and indium trichloride
Inter- and intramolecular palladium-catalyzed ally! cross-coupling reactions using allylindium generated in situ by treatment of allyl acetates with indium and indium trichloride in the presence of Pd0 catalyst and nBuNMe2 in DMF were successfully demonstrated. Allylindium species generated in situ by reductive transmetalation of π- allylpalladium(II) complexes, obtained from a variety of allyl acetales in the presence of Pd0 catalyst together with indium and indium trichloride, were found to be capable of acting as effective nucleophilic coupling partners in Pd-catalyzed cross-coupling reactions. A variety of allyl acetates such as but-l-en-3-yl acetate, crotyl acetate, and 2-methylallyl acetate afforded the corresponding allylic compounds in good yields in cross-coupling reactions. Various electrophilic cross-coupling partners such as aryl iodides and vinyl bromides and triflates participate in these reactions. Not only intermolecular but also intramolecular Pd-catalyzed cross-coupling reactions work equally well to produce the desired allylic coupling products in good yields.
Seomoon, Dong,Lee, Kooyeon,Kim, Hyunseok,Lee, Phil Ho
p. 5197 - 5206
(2008/02/10)

Homocoupling of arylboronic acids with a catalyst system consisting of a palladium(II) N-heterocyclic carbene complex and p-benzoquinone
In the presence of 1-3 mol% SIPr-ligated Pd(OAc)2 and 0.6 equivalent of p-benzoquinone, various arylboronic acids underwent homocoupling in MeOH at ambient temperature to produce symmetrical biaryls in 38-96% yields. Georg Thieme Verlag Stuttgart.
Yamamoto, Yoshihiko
p. 1913 - 1916
(2008/03/13)

Synthesis of indenes by the transition metal-mediated carboannulation of alkynes
The synthesis of highly substituted indenes has been achieved by three different transition metal-mediated methods. The first method involves the palladium-catalyzed carboannulation of internal alkynes. The second method utilizes a two-step approach, which involves first the palladium/copper- catalyzed cross-coupling of terminal alkynes with appropriately functionalized aryl halides, followed by copper-catalyzed intramolecular cyclization. The third method involves intermolecular palladium-catalyzed arylation of the arylalkynes formed in the first step of the second method.
Zhang, Daohua,Liu, Zhijian,Yum, Eul K.,Larock, Richard C.
p. 251 - 262
(2007/10/03)

2,2′-bipyridine: An efficient ligand in the cobalt-catalyzed synthesis of organozinc reagents from aryl chlorides and sulfonates
The synthesis of functionalized arylzinc reagents from aromatic chlorides, triflates, or mesylates, via cobalt catalysis, is reported using 2,2′-bipyridine as a ligand in a mixture of acetonitrile and pyridine. This procedure allows the synthesis of a variety of functionalized arylzinc species in good to excellent yields. Some of these arylzinc compounds have been coupled with aromatic bromides under palladium catalysis. Georg Thieme Verlag Stuttgart.
Kazmierski, Igor,Gosmini, Corinne,Paris, Jean-Marc,Périchon, Jacques
p. 881 - 884
(2007/10/03)

Palladium-catalyzed homocoupling and cross-coupling reactions of aryl halides in poly(ethylene glycol)
The direct coupling of aryl halides to prepare symmetrical and unsymmetrical biaryls were performed successfully in poly(ethylene glycol) (PEG) using Pd(OAc)2 as the catalyst in the absence of other additives or reductants. The selectivity toward biaryl depended on the amount of PEG used. Excessive PEGs induce the increase of hydrodehalogenation product, and the best selectivity to biaryl is obtained when the concentration of the hydroxyl group in PEG achieves 100 mol% relative to aryl halides. The catalyst system could be recycled and reused up to five times with no loss of catalytic activity.
Wang, Liang,Zhang, Yuhong,Liu, Leifang,Wang, Yanguang
p. 1284 - 1287
(2007/10/03)

Transition-metal-free homocoupling of organomagnesium compounds
(Chemical Equation Presented) Without palladium or copper: A wide range of functionalized Grignard compounds were coupled by using diphenoquinone 1 as an electron acceptor. The oxidative dimerization of alkenylmagnesium reagents proceeds with complete retention of the stereochemistry (see scheme; TBDMS = tert-butyldimethylsilyl).
Krasovskiy, Arkady,Tishkov, Alexander,Del Amo, Vicente,Mayr, Herbert,Knochel, Paul
p. 5010 - 5014
(2007/10/03)