1166-18-3Relevant academic research and scientific papers
Nickel-Catalyzed Formal Homocoupling of Methoxyarenes for the Synthesis of Symmetrical Biaryls via C-O Bond Cleavage
Nakamura, Keisuke,Tobisu, Mamoru,Chatani, Naoto
, p. 6142 - 6145 (2015)
A new method has been developed for the nickel-catalyzed homocoupling of methoxyarenes via C-O bond cleavage using a diboron reagent. The use of 1,3-dicyclohexylimidazol-2-ylidene as a ligand was found to be critical to the success of the reaction. This new method allows the synthesis of a wide range of biaryl compounds.
Homocoupling of arylboronic acids catalyzed by 1,10-phenanthroline-ligated copper complexes in air
Kirai, Naohiro,Yamamoto, Yoshihiko
, p. 1864 - 1867 (2009)
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.
Reductive Coupling of Aryl Halides via C—H Activation of Indene
Zhang, Bo-Sheng,Yang, Ying-Hui,Wang, Fan,Gou, Xue-Ya,Wang, Xi-Cun,Liang, Yong-Min,Li, Yuke,Quan, Zheng-Jun
, p. 1573 - 1579 (2021)
This paper describes the first case of a reductive coupling reaction with indene, a non-heteroatom olefin used as a reducing agent. The scope of the substrate is wide. The homo-coupling, cross-coupling, and synthesis of 12 and 14-membered rings were realized. The control experiment, indene-product curve and density functional theory calculations showed that the η3-palladium indene intermediate was formed by C—H activation in the presence of cesium carbonate. We speculate that the final product was obtained through a Pd (IV) intermediate or aryl ligand exchange. In addition, we excluded the formation of palladium anion (Pd(0)?) intermediates.
Synthesis of biaryl compounds via Suzuki homocoupling reactions catalyzed by metal organic frameworks encapsulated with palladium nanoparticles
Bao, Yan-Sai,Cui, Xin-Yu,Han, Zheng-Bo,Li, Xin,Tang, Hong,Yang, Ming,Zhang, Yu-Yang,Zhao, Kun,Zhou, Mei-Li
, (2020/12/17)
Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd?MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene.
Synthesis of Enaminone-Pd(II) Complexes and Their Application in Catalysing Aqueous Suzuki-Miyaura Cross Coupling Reaction
Fu, Leiqing,Cao, Xiaoji,Wan, Jie-Ping,Liu, Yunyun
, p. 254 - 258 (2020/01/25)
A series of Pd(II)-enaminone complexes, termed Pd(eao)2, have been synthesized and characterized. The investigation on the catalytic activities of these new Pd(II)-reagents has proved that the Pd(eao)2-1 possesses excellent catalytic activity for the Suzuki- Miyaura cross coupling reactions of aryl bromides/chlorides with aryl/vinyl boronic acids in the environmentally benign media of aqueous PEG400 at low loading (5 mol‰). The superiority of this Pd(II)-reagent to those commercial Pd(II) and Pd(0) catalysts in catalyzing the reactions has been confirmed by parallel experiments. What's more, Pd(eao)2-2 has been found as a practical catalyst for the homo-coupling reactions of aryl boronic acids.
Acid-catalyzed rearrangements in arenes: Interconversions in the quaterphenyl series
Skraba-Joiner, Sarah L.,Holt, Carter J.,Johnson, Richard P.
, p. 2655 - 2663 (2019/12/11)
Arenes undergo rearrangement of phenyl, alkyl, halogen and other groups through the intermediacy of ipso arenium ions in which a proton is attached at the same carbon as the migrating substituent. Interconversions among the six quaterphenyl isomers have b
Role of the base and control of selectivity in the suzuki-miyaura cross-coupling reaction
Lima, Carlos F. R. A. C.,Rodrigues, Ana S. M. C.,Silva, Vera L. M.,Silva, Artur M. S.,Santos, Luis M. N. B. F.
, p. 1291 - 1302 (2014/05/20)
The outcome of the Suzuki-Miyaura cross-coupling for the direct competition reaction between two boronic acids was evaluated under routine synthesis conditions. The reaction selectivity was found to depend on the amount of the base used, with fewer bases
Active-alkali metal promoted reductive desulfurization of dibenzothiophene and its hindered analogues
Pittalis, Mario,Azzena, Ugo,Pisano, Luisa
, p. 207 - 211 (2013/01/15)
Dibenzothiophene and some related organosulfur compounds are efficiently reductively desulfurized under mild reaction conditions, with Na and/or Li metal in the presence of a catalytic amount of tetraphenylethylene in THF at room temperature. This simple methodology was applied to the synthesis of several substituted biphenyls, thus realizing a connection between the directing properties of the sulfur atom of dibenzothiophene and the efficiency of 1,2-dianions of tetraphenylethane as homogenous electron transfer reagents.
Syntheses and Spectral Characteristics of Seven Polyphenyls Containing Highly Branched para-Phenylene Ring(s)
Fujioka, Yasuhiro,Ozasa, Shigeru,Sato, Kazumi,Ibuki, Eiichi
, p. 22 - 29 (2007/10/02)
Seven polyphenyls, including four new compounds, 2,2',6'- (2) and 3,2',6'-triphenyl-p-terphenyl (3), 3',5'-diphenyl-p-quarterphenyl (4), and 2-phenyl-3'-(2-biphenylyl)-p-terphenyl (7), were synthesized by the Ullmann coupling reaction of aryl iodide(s) or by the Kharash type coupling reaction of aryl Grignard reagent with an aryl iodide catalyzed by bis(acetylacetonato)-nickel(II).Infrared spectral studies of the polyphenyls showed that the range of 730-770 cm-1, generally accepted as the position of the out-of-plane C-H bending bands of the phenyl ring, should be widened slightly to 730-786 cm-1.The high frequency bands were confirmed to be correlated closely to the overcrowding by terminal rings in the complex structures.Proton magnetic resonance spectral studies indicated that he characteristic spectral features of the branched polyphenyls were consistent with their conformational aspects deduced from stereomodels.In the ultraviolet spetcral studies the polyphenyls containing highly branched p-phenylene ring(s) showed intense K-bands or shoulders at locations very similar to those of the corresponding linear polyphenyls containing the same number of p-phenylene rings. Keywords -- Ullmannn reaction; Ni-complex-catalyzed cross-coupling; quinquephenyl; sexiphenyl; octiphenyl; IR; UV; 1H-NMR
Syntheses and Spectral Properties of Several Branched-chain Polyphenyls containing 1,3,5-Trisubstituted Ring(s)
Ozasa, Shigeru,Fujioka, Yasuhiro,Hashino, Hiromi,Kimura, Naoko,Ibuki, Eiichi
, p. 2313 - 2320 (2007/10/02)
Six polyphenyls, including four new compounds, 5',5''-di(2-biphenylyl)-2,2'''-diphenyl-m-quaterphenyl (3), 2,5',2''-triphenyl-m-terphenyl (4), 3,5-di(2-biphenylyl)-o-terphenyl (5), and 5''-(3-biphenylyl)-m-quinquephenyl (6), were synthesized by the Ullmann coupling reaction of iodo compounds.Proton magnetic resonance spectral studies indicated that the characteristic spectral features of the polyphenyls containing 1,3,5-trisubstituted ring system(s) were fully compatible with their conformational aspects deduced from stereomodels.Ultraviolet spectral data indicated that the dihedral angle of the pivot bond of the branched ring in the polyphenyls in solution is very similar to that of biphenyl.Keywords - Ullmann reaction; quinquephenyl; sexiphenyl; septiphenyl; decaphenyl; polyphenyl; IR; UV; 1H-NMR
