1210-05-5Relevant articles and documents
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Chapman,Meinwald
, p. 162,164 (1958)
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Identification of a Surprising Boronic Acid Homocoupling Process in Suzuki-Miyaura Cross-Coupling Reactions Utilizing a Hindered Fluorinated Arene
Gargaro, Samantha L.,Dunson, Bre'Shon,Sieber, Joshua D.
, p. 511 - 516 (2021)
The Suzuki-Miyaura cross-coupling reaction of 2-bromo-1,3-bis(trifluoromethyl)benzene with arylboronic acids was evaluated and determined to suffer from the formation of large amounts of boronic acid homocoupling products in conjunction with dehalogenation. Homocoupling product formation in this process likely occurs through a rare protonolysis/second transmetalation event rather than by the well-established mechanism requiring the involvement of O 2. The scope of this boronic acid homocoupling reaction was investigated and shown to predominate with electron-deficient arylboronic acids. Finally, a good yield of cross-coupling products could be obtained by employing dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (SPhos) as the ligand.
An efficient one-pot approach to phenanthrene derivatives using a catalyzed tandem Ullmann-pinacol coupling reaction
Lin, Shuang-zheng,You, Tian-pa
, p. 9906 - 9910 (2008)
In the presence of catalyst (Ph3P)2NiCl2 and reductant Zn, the Ullmann reactions of ortho-halo aryl aldehydes generate biaryl-dialdehydes and zinc halides. Subsequently, ZnX2 can catalyze the intramolecular pinacol coupling reaction of biaryl-dialdehydes to form 9,10-dihydrophenanthrene-9,10-diols. One-pot synthesis of 9-phenanthrols can be achieved using this strategy.
Role of Copper Species in the Oxidative Dimerization of Arylboronic Acids: Synthesis of Symmetrical Biaryls
Demir, Ayhan S.,Reis, Oemer,Emrullahoglu, Mustafa
, p. 10130 - 10134 (2003)
Certain Cu(I) and Cu(II) salts are able to mediate the dimerization of arylboronic acids in DMF. They provide the corresponding symmetrical biaryls in moderate to very good yields. It is possible to run the reaction catalytically under an oxygen atmosphere without a significant loss of yields.
A novel and efficient method for the direct synthesis of pyrrolyl or indolyl substituted 9,10-dihydrophenanthren-9-ol analogues
Song, Gonghua,Wang, Jiayi,Xia, Qi,Zhang, Juan,Zhao, Xinlei
, (2019)
A novel domino intramolecular [3+2] cycloaddtion and ring-opening aromatization process has been successfully developed for the efficient direct synthesis of pyrrolyl or indolyl substituted 9,10-dihydrophenanthren-9-ol analogues. And 1-(phenanthren-9-yl)-
Mechanistic investigations of a palladium-diene catalyzed Suzuki-Miyaura cross-coupling reaction
He, Xiaoshuang,Zhang, Shusheng,Guo, Yinlong,Wang, Haoyang,Lin, Guoqiang
, p. 2945 - 2948 (2012)
The mechanism of the first example of a palladium diene catalyzed asymmetric Suzuki-Miyaura cross-coupling reaction has been validated, with the key palladium intermediates captured and characterized. The identified species corresponding to each catalytic step were firmly associated with the diene ligand in our observations. In the ESI-MS/MS experiments by CID (collision-induced dissociation), the fragmentation of the gas-phase transmetalation species was consistent with the product-yielding process in the reductive elimination step and thus revealed the catalytically active species of the reaction system.
New mono- and di-nuclear complexes of PdII, PtII and NiII of PNNP ligands with a 2,2′-biaryl bridging unit
Ligtenbarg, Alette G. J.,Van Den Beuken, Esther K.,Meetsma, Auke,Veldman, Nora,Smeets, Wilberth J. J.,Spek, Anthony L.,Feringa, Ben L.
, p. 263 - 270 (1998)
The Schiff bases 2,2′-bis{N-[(2-diphenylphosphino)phenyl]formimidoyl}biphenyl (L1) and 2,2′-bis{[(2-diphenylphosphino)benzylidene]amino}biphenyl (L2) were synthesized from the appropriate amine and aldehyde. Their co-ordination behaviour towards PdII, PtII and NiII has been studied. Dinuclear complexes were formed when treating L1 with 2 equivalents of [PdCl(Me)(cod)] (cod = cycloocta-1,5-diene) and Pd(O2CMe)2. In the case of the reaction of L1 with Pd(O2CMe)2 an unexpected double cyclopalladated complex was formed. However, treatment of L1 with 2 equivalents of [PtCl2(MeCN)2] resulted in hydrolysis of the ligand and a mononuclear complex of (2-diphenylphosphino)benzenamine was obtained. The structure of [Pd2L1Cl2Me2] 1 has been established by an X-ray diffraction study. The dihedral angle between the biphenyl rings is 49.2(8)° and the intramolecular Pd ... Pd distance is 7.165(3) A. The biphenyl bridging moiety shows a remarkable bending of 169.2(8)°. Treatment of 1 with carbon monoxide resulted in a double CO insertion, yielding the bis(acetyl)palladium compound [Pd2L1Cl2-{C(O)Me}2] 2. The structure of [Pd2L1(O2CMe)2]·4CH 2Cl2 3 was also determined by X-ray diffraction. The dihedral angle between the biphenyl rings is 75.9(14)° while the intramolecular Pd ... Pd distance is 8.655(2) A. The reaction of L2 with 2 equivalents of anhydrous [PdCl2(MeCN)2] or NiCl2 afforded mononuclear complexes. The crystal and molecular structure of [PdL2]Cl2·3.5CH2Cl2 was determined. The compound has an approximately square-planar P2N2 geometry.
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Agranat,I. et al.
, p. 1936 - 1941 (1979)
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A novel palladium-catalyzed homocoupling reaction initiated by transmetallation of palladium enolates
Lei, Aiwen,Zhang, Xumu
, p. 2525 - 2528 (2002)
Palladium-catalyzed homocoupling reaction of aryl boronic acids has been developed using a protocol similar to the well-documented crosscoupling reaction. α-Halocarbonyl compounds are applied to initiate the reaction via oxidative addition to a palladium(0) species. The resulting palladium enolate halide can promote the double transmetallation. Reductive elimination generates the desire homocoupling product.
Synthesis of a coumarin compound from phenanthrene by a TiO 2-photocatalyzed reaction
Higashida, Suguru,Harada, Aiko,Kawakatsu, Rikako,Fujiwara, Noriko,Matsumura, Michio
, p. 2804 - 2806 (2006)
Phenanthrene was converted into a coumarin compound by a TiO 2-photocatalyzed reaction in an acetonitrile solution containing 8 wt% water and molecular oxygen in 45% yield. The Royal Society of Chemistry 2006.
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Dey,A.S.,Neumeyer,J.L.
, p. 1095 - 1100 (1974)
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Mechanistic Insights into Selective Oxidation of Polyaromatic Compounds using RICO Chemistry
Nowicka, Ewa,Hickey, Niamh W.,Sankar, Meenakshisundaram,Jenkins, Robert L.,Knight, David W.,Willock, David J.,Hutchings, Graham J.,Francisco, Manuel,Taylor, Stuart H.
, p. 12359 - 12369 (2018)
Ruthenium-ion-catalyzed oxidation (RICO) of polyaromatic hydrocarbons (PAHs) has been studied in detail using experimental and computational approaches to explore the reaction mechanism. DFT calculations show that regioselectivity in these reactions can be understood in terms of the preservation of aromaticity in the initial formation of a [3+2] metallocycle intermediate at the most-isolated double bond. We identify two competing pathways: C?C bond cleavage leading to a dialdehyde and C-H activation followed by H migration to the RuOx complex to give diketones. Experimentally, the oxidation of pyrene and phenanthrene has been carried out in monophasic and biphasic solvent systems. Our results show that diketones are the major product for both phenanthrene and pyrene substrates. These diketone products are shown to be stable under our reaction conditions so that higher oxidation products (acids and their derivatives) are assigned to the competing pathway through the dialdehyde. Experiments using 18O-labelled water do show incorporation of oxygen from the solvents into products, but this may take place during the formation of the reactive RuO4 species rather than directly during PAH oxidation. When the oxidation of pyrene is carried out using D2O, a kinetic isotope effect (KIE) is observed implying that water is involved in the rate-determining step leading to the diketone products.
Chromium-Catalyzed Selective Cross-Electrophile Coupling between Unactivated C(aryl)-F and C(aryl)-O Bonds
Fan, Fei,Zhao, Lixing,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 561 - 568 (2022/03/15)
Chemically inert C(aryl)-F bonds have rarely been used to couple with other unactivated bonds, and this remains a challenge because of the difficulty of the successive cleavage of two unactivated bonds by metal catalysis. We report here the chromium-catalyzed cleavage of chemically inert C(aryl)-F bonds for coupling with unactivated C(aryl)-O bonds, allowing cross-electrophile coupling between unreactive aryl fluorides and aryl esters to be achieved in high regio- and chemoselectivity. The reactive Cr, which was formed in situ by reducing CrCl2, enables cleavage of the o-C(aryl)-F bonds to afford monovalent and quartet cyclochromate; subsequent bipyridyl-enabled insertion into the ester C(aryl)-O bond followed by reductive elimination allowed the orthogonal coupling of these two different and unactivated bonds. Mechanistic studies indicate that the bipyridyl ligand greatly enhances the reactivity of Cr in the cleavage of C(aryl)-O bonds, and the second oxidative addition may occur sluggishly compared with the reductive elimination in the catalytic cycle.
Porphyrin n-pincer pd(Ii)-complexes in water: A base-free and nature-inspired protocol for the oxidative self-coupling of potassium aryltrifluoroborates in open-air
Prasad, Sana Siva,Naidu, Bandameeda Ramesh,Hanafiah, Marlia M.,Lakshmidevi, Jangam,Marella, Ravi Kumar,Lakkaboyana, Sivarama Krishna,Venkateswarlu, Katta
, (2021/09/13)
Metalloporphyrins (and porphyrins) are well known as pigments of life in nature, since representatives of this group include chlorophylls (Mg-porphyrins) and heme (Fe-porphyrins). Hence, the construction of chemistry based on these substances can be based on the imitation of biological systems. Inspired by nature, in this article we present the preparation of five different porphyrin, meso-tetraphenylporphyrin (TPP), meso-tetra(p-anisyl)porphyrin (TpAP), tetra-sodium meso-tetra(p-sulfonatophenyl)porphyrin (TSTpSPP), meso-tetra(m-hydroxyphenyl)porphyrin (TmHPP), and meso-tetra(m-carboxyphenyl)porphyrin (TmCPP) as well as their N-pincer Pd(II)-complexes such as Pd(II)-meso-tetraphenylporphyrin (PdTPP), Pd(II)-meso-tetra(p-anisyl)porphyrin (PdTpAP), Pd(II)-tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (PdTSTpSPP), Pd(II)-meso-tetra(m-hydroxyphenyl)porphyrin (PdTmHPP), and Pd(II)-meso-tetra(m-carboxyphenyl)porphyrin (PdTmCPP). These porphyrin N-pincer Pd(II)-complexes were studied and found to be effective in the base-free self-coupling reactions of potassium aryltrifluoroborates (PATFBs) in water at ambient conditions. The catalysts and the products (symmetrical biaryls) were characterized using their spectral data. The high yields of the biaryls, the bio-mimicking conditions, good substrate feasibility, evading the use of base, easy preparation and handling of catalysts, and the application of aqueous media, all make this protocol very attractive from a sustainability and cost-effective standpoint.
