- PREPARATION OF DIPHENYL COMPOUNDS
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This disclosure relates to the preparation of diphenyl compounds, especially dimethylbiphenyl compounds, in which there is one methyl group on each ring, and their oxidized analogues. These compounds, and particularly alkylated biphenyl compounds and biphenylcarboxylic acids, alcohols and esters, are useful intermediates in the production of a variety of commercially valuable products, including polyesters and plasticizers for PVC and other polymer compositions.
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Paragraph 0040
(2019/10/29)
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- Cross-Coupling Reactions of Alkyl Halides with Aryl Grignard Reagents Using a Tetrachloroferrate with an Innocent Countercation
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Bis(triphenylphosphoranylidene)ammonium tetrachloroferrate, (PPN)[FeCl4] (1), was evaluated as a catalyst for cross-coupling reactions. 1 exhibits high stability toward air and moisture and is an effective catalyst for the reaction of secondary alkyl halides with aryl Grignard reagents. The PPN cation is considered as an innocent counterpart to the iron center. We have developed an easy-to-handle iron catalyst for “ligand-free” cross-coupling reactions. (Figure presented.).
- Hashimoto, Toru,Maruyama, Tsubasa,Yamaguchi, Takamichi,Matsubara, Yutaka,Yamaguchi, Yoshitaka
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supporting information
p. 4232 - 4236
(2019/08/16)
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- Enabling the Cross-Coupling of Tertiary Organoboron Nucleophiles through Radical-Mediated Alkyl Transfer
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The construction of quaternary centers is a common challenge in the synthesis of complex materials and natural products. Current cross-coupling strategies that can be generalized for setting these centers are sparse and, when known, are typically predicated on the use of reactive organometallic reagents. To address this shortcoming a new, photoredox-Ni dual catalytic strategy for the cross-coupling of tertiary organoboron reagents with aryl halides is reported. In addition to details on the cross-coupling scope and limitations, full screening efforts and mechanistic experiments are communicated.
- Primer, David N.,Molander, Gary A.
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p. 9847 - 9850
(2017/08/02)
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- Enantiospecific Synthesis of ortho-Substituted Benzylic Boronic Esters by a 1,2-Metalate Rearrangement/1,3-Borotropic Shift Sequence
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Coupling reactions between benzylamines and boronic esters have been investigated. ortho-Lithiated benzylamines react with boronic esters and a N-activator to afford ortho-substituted benzylic boronic esters with formal 1,1′-benzylidene insertion into the C-B bond. The reaction occurs by a SN2′ elimination and 1,2-metalate rearrangement of the N-activated boronate complex to afford a dearomatized intermediate, which undergoes a Lewis-acid catalyzed 1,3-borotropic shift to afford the boronic ester products in high yield and with excellent enantiospecificity. The use of enantioenriched α-substituted benzylamines gave the corresponding secondary boronic esters with high ee.
- Aichhorn, Stefan,Bigler, Raphael,Myers, Eddie L.,Aggarwal, Varinder K.
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p. 9519 - 9522
(2017/07/25)
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- Sterically congested phosphonium borate acids as effective Br?nsted acid catalysts
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Phosphonium borate acids [HPPh2(C6F5)][B(C6F5)4] (2), [HPMes2(C6F5)][B(C6F5)4] (3) and [HPMes(C6F5)2][B(C6F5)4] (4) were synthesized via heterolytic dihydrogen cleavage in the presence of triisopropylsilylium and characterized by spectroscopic and crystallographic methods. Br?nsted acid catalysis using compounds 2–4 proved to be efficient for a number of challenging reactions (namely ionic hydrogenation, hydroamination and hydroarylation), owing to the restrained nucleophilicity of the sterically hindered conjugate bases. Reactivity of compounds 2–4 suggests that their pKavalues are similar to that of diethyl oxonium acid.
- Sinha, Arup,Jaiswal, Amit K.,Young, Rowan D.
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- Nickel-catalyzed selective oxidative radical cross-coupling: An effective strategy for inert Csp3-H functionalization
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An effective strategy for inert Csp3-H functionalization through nickel-catalyzed selective radical cross-couplings was demonstrated. Density functional theory calculations were conducted and strongly supported the radical cross-coupling pathway assisted by nickel catalyst, which was further confirmed by radical-trapping experiments. Different arylborates including arylboronic acids, arylboronic acid esters and 2,4,6-triarylboroxin were all good coupling partners, generating the corresponding Csp3-H arylation products in good yields.
- Liu, Dong,Li, Yuxiu,Liu, Chao,Lei, Aiwen,Qi, Xiaotian,Lan, Yu.
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supporting information
p. 998 - 1001
(2015/03/30)
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- Alkylations of Arylboronic Acids including Difluoroethylation/Trifluoroethylation via Nickel-Catalyzed Suzuki Cross-Coupling Reaction
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An efficient alkylation method of functionalized alkyl halides under mild nickel-catalyzed C(sp3)-(sp2) Suzuki cross-coupling conditions is described. The features of this approach are excellent functional group compatibility, low cost nickel catalyst, and the use of a mild base. This is also the first successful example of the nickel-catalyzed direct 2,2-difluoroethylation or 2,2,2-trifluoroethylation of aryl-/heteroarylboronic acids.
- Zhang, Xiaofei,Yang, Chunhao
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supporting information
p. 2721 - 2727
(2015/09/01)
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- Iron-catalyzed arene alkylation reactions with unactivated secondary alcohols
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A simple, iron-based catalytic system allows for the inter- and intramolecular arylation of unactivated secondary alcohols. This transformation expands the substrate scope beyond the previously required activated alcohols and proceeds under mild reaction conditions, tolerating air and moisture. Furthermore, the use of an enantioenriched secondary alcohol provides an enantioenriched product for the intramolecular reaction, thereby offering a convenient approach to nonracemic products.
- Jefferies, Latisha R.,Cook, Silas P.
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supporting information
p. 2026 - 2029
(2014/05/06)
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- Efficient cross-coupling of aryl Grignard reagents with alkyl halides by recyclable ionic iron(iii) complexes bearing a bis(phenol)-functionalized benzimidazolium cation
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A novel bis(phenol)-functionalized benzimidazolium salt, 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzyl)benzimidazolium chloride (H 3LCl, 1), was designed and used to prepare ionic iron(iii) complexes of the type [H3L][FeX4] (X = Cl, 2; X = Br, 3). Both 2 and 3 were characterized by elemental analysis, Raman spectroscopy, electrospray ionization mass spectrometry and X-ray crystallography. The catalytic performances of 2 and 3 in cross-coupling reactions using aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens were studied. This analysis shows that complex 2 has good potential for alkyl chloride-mediated coupling. In comparison, complex 3 showed slightly lower catalytic activity. After decanting the product contained in the ethereal layer, complex 2 could be recycled at least eight times without significant loss of catalytic activity.
- Xia, Chong-Liang,Xie, Cun-Fei,Wu, Yu-Feng,Sun, Hong-Mei,Shen, Qi,Zhang, Yong
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p. 8135 - 8144
(2013/12/04)
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- IRON BISPHENOLATE COMPLEXES AND METHODS OF USE AND SYNTHESIS THEREOF
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The present application, relates to iron bisphenolate complexes and methods of use and synthesis thereof. The iron complexes are prepared from tridentate or tetradentate ligands of Formula I: wherein R1 and R2 are as defined herein. Also provided are methods and processes of using the iron bisphenolate complexes as catalysts in cross-coupling reactions and in controlled radical polymerizations.
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Paragraph 00187-00191
(2013/04/25)
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- Ionic iron(iii) complexes of bis(phenol)-functionalized imidazolium cations: Synthesis, structures and catalysis for aryl Grignard cross-coupling of alkyl halides
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A series of bis(phenol)-functionalized imidazolium salts, 1,3-bis(4,6-di-R1-2-hydroxybenzyl)-2-R2-4,5-di-R 3-imidazolium chlorides H3LnCl (R1 = tBu, R2 = R3 = H, H3L 1Cl, 1; R1 = CH3, R2 = R3 = H, H3L2Cl, 2; R1 = tBu, R 2 = H, R3 = Cl, H3L3Cl, 3; R 1 = tBu, R2 = CH3, R3 = H, H3L4Cl, 4), were used to produce a novel series of ionic iron(iii) complexes [H3Ln][FeX4] (n = 1, X = Cl, 5; n = 2, X = Cl, 6; n = 3, X = Cl, 7; n = 4, X = Cl, 8; n = 1, X = Br, 9; n = 3, X = Br, 10). All of the complexes were characterized by Raman spectroscopy and electrospray ionization mass spectrometry. Elemental analysis and X-ray crystallography were also used. All of the complexes were non-hygroscopic and air-stable, with five of them existing as solids (5, 7-10) and one as an oil (6) at room temperature. A preliminary catalytic study on the cross-coupling reactions of aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens, revealed that all of the ionic iron(iii) complexes exhibited good to excellent catalytic activity. Complexes 5, 6 and 8 exhibited optimal activity, whereas 7, 9 and 10 showed only moderate activity. Furthermore, by simply decanting the cross-coupling product in the ether layer, complexes 5 and 6 could be reused in at least seven successive runs without significant loss in catalytic activity.
- Deng, Hai-Ning,Xing, Ya-Lin,Xia, Cong-Liang,Sun, Hong-Mei,Shen, Qi,Zhang, Yong
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p. 11597 - 11607
(2013/02/23)
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- Synthesis of iron(III) complex bearing tridentate β-Aminoketonato Ligand: Application to iron-catalyzed cross-coupling reaction of arylmagnesium bromides with alkyl halides
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A tridentate β-aminoketonato iron complex was prepared by the reaction of lithium β-aminoketonato with FeCl3. This iron complex was found to be an efficient catalyst for the crosscoupling reaction between arylmagnesium bromides and alkyl halides.
- Yamaguchi, Yoshitaka,Ando, Hiroaki,Nagaya, Makoto,Hinago, Hideto,Ito, Takashi,Asami, Masatoshi
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supporting information; experimental part
p. 983 - 985
(2011/12/05)
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- Kumadatamaocorriu coupling of alkyl halides catalyzed by an ironbisphosphine complex
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An iron(II) chloride complex possessing a sterically demanding ortho-phenylene-tethered bisphosphine ligand shows a high catalytic activity in the KumadaTamaoCorriu coupling of nonactivated alkyl halides with aryl Grignard reagents. Primary, secondary, and tertiary alkyl halides can participate as an electrophilic coupling partner. A radical clock experiment using (iodomethyl)cyclopropane exclusively gives the corresponding ring-opening coupling product, suggesting intermediacy of alkyl radical species.
- Hatakeyama, Takuji,Fujiwara, Yu-Ichi,Okada, Yoshihiro,Itoh, Takuma,Hashimoto, Toru,Kawamura, Shintaro,Ogata, Kazuki,Takaya, Hikaru,Nakamura, Masaharu
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supporting information; experimental part
p. 1030 - 1032
(2011/12/05)
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- Synthesis, structure, and C-C cross-coupling activity of (amine)bis(phenolato)iron(acac) complexes
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A series of (amine)bis(phenolato)iron(III)acac complexes has been prepared and characterized. Reaction of Fe(acac)3 with the diprotonated linear tetradentate proligand N,N′-bis(4,6-di-tert-butyl-2-methylphenol)-N, N′-dimethyl-1,2-diaminoethane, H2[L1], and tripodal tetradentate ligand precursors dimethylaminoethylamino-N,N-bis(2-methylene-4,6- di-tert-butylphenol), H2[L2], dimethylaminoethylamino-N,N-bis(2- methylene-4-methyl-6-tert-butylphenol), H2[L3], 2-methoxyethylamino- N,N-bis(2-methylene-4,6-di-tert-butylphenol), H2[L4], 2-methoxyethylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), H 2[L5], and 2-methoxyethylamino-N,N-bis(2-methylene-4,6- dimethylphenol), H2[L6], produces the distorted octahedral Fe III complexes [L1]Fe(acac) (1), [L2]Fe(acac) (2), [L3]Fe(acac) (3), [L4]Fe(acac) (4), [L5]Fe(acac) (5), and [L6]Fe(acac) (6). In all of these complexes, the phenolato oxygen atoms are cis-oriented. The paramagnetic Fe III complexes 1-6 were also characterized by UV/Vis and IR spectroscopy, mass spectrometry, cyclic voltammetry, and magnetic measurements. Single crystal X-ray molecular structures have been determined for complexes 1, 2, 3, 5, and the proligand H2[L6]. Preliminary investigations of complexes 1-6 for catalytic cross-coupling reactions of aryl Grignard reagents with cyclic and acyclic secondary alkyl halides and benzyl halides were performed. While the activity for cyclohexyl chlorides and bromides was high, cross-coupling of benzyl halides was moderate and 2-bromo- and 2-chlorobutane gave poor yields of cross-coupled product.
- Hasan, Kamrul,Dawe, Louise N.,Kozak, Christopher M.
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experimental part
p. 4610 - 4621
(2011/12/03)
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- CATALYST FOR CROSS-COUPLING REACTION, AND PROCESS FOR PRODUCTION OF AROMATIC COMPOUND USING THE SAME
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The present invention provides a process for efficiently producing an alkylated aromatic compound in good yield, by a cross-coupling reaction between an alkyl halide and an aromatic magnesium reagent. A process for producing an aromatic compound represented by Formula (1): [in-line-formulae]R—Ar′??(1)[/in-line-formulae]wherein R is a hydrocarbon group, and Ar′ is an aryl group;the process comprising:reacting a compound represented by Formula (2): [in-line-formulae]R—X??(2)[/in-line-formulae]wherein X is a halogen atom, and R is as defined above, with a magnesium reagent represented by Formula (3): [in-line-formulae]Ar′—MgY??(3)[/in-line-formulae]wherein Y is a halogen atom, and Ar′ is as defined above, in the presence of a catalyst for cross-coupling reactions comprising an iron compound and a bisphosphine compound represented by Formula (4): wherein Q is a divalent group derived from an aromatic ring by removing two hydrogen (H) atoms on adjacent carbon atoms; and each Ar is independently an aryl group.
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Page/Page column 17
(2011/07/06)
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- Catalytic alkylation of aryl Grignard reagents by iron(iii) amine-bis(phenolate) complexes
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Reaction of n-propylamino-N,N-bis(2-methylene-4-tert-butyl-6-methylphenol), H2L1, n-propylamino-N,N-bis(2-methylene-4,6-di-tert-butylphenol), H2L2, and benzylamino-N,N-bis(2-methylene-4-tert-butyl-6- methylphenol), H2L3, with anhydrous ferric chloride in the presence of base yields the products, [FeL1(μ-Cl)]2 (1), [FeL2(μ-Cl)]2 (2) and [FeL3(μ-Cl)]2 (3). In the solid state, these complexes exist as chloride-bridged dimers giving distorted trigonal bipyramidal iron(iii) ions. Reaction of H2L1 with FeBr 3, however, results in the formation of a tetrahedral iron(iii) complex possessing two bromide ligands. The amine-bis(phenolate) ligand is bidentate in this complex and bonds to the iron(iii) ion via the phenolate O-donors. The central amine donor is protonated, resulting in a quaternized ammonium fragment and the iron(iii) centre possesses a negative formal charge. As a result, this complex is zwitterionic and formulated as FeBr2L1H (4). Complex 1 is an air-stable, non-hygroscopic, single-component catalyst for C-C cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides, including chlorides. Good to excellent yields of cross-coupled products are obtained in diethyl ether at room temperature. In some cases where low yields are obtained under these conditions, the use of microwave-assisted heating of the reaction mixture can improve yields. The Royal Society of Chemistry 2011.
- Qian, Xin,Dawe, Louise N.,Kozak, Christopher M.
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experimental part
p. 933 - 943
(2011/04/23)
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- A catalytic C-C bond-forming reaction between aliphatic fluorohydrocarbons and arylsilanes
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C-C coupling reactions between arylsilanes and alkylfluorides are efficiently catalyzed by disilyl cation 1. Primary as well as secondary alkylfluorides were quantitatively coupled with arylsilanes; however, in the case of tertiary fluorides, the hydrodef
- Luehmann, Nicole,Panisch, Robin,Mueller, Thomas
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experimental part
p. 533 - 537
(2010/10/19)
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- Cross-coupling reactions through the intramolecular activation of Alkyl(triorgano)silanes
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(Figure Presented) Cross-Si-ing the Jordan: Cross-coupling reactions of 2-(2-hydroxyprop-2-yl)phenylsubstituted alkylsilanes with a variety of aryl halides proceed in the presence of palladium and copper catalysts. The use of K3PO4 base allows for highly chemoselective alkyl coupling with both primary and secondary alkyl groups (Alk).
- Nakao, Yoshiaki,Takeda, Masahide,Matsumoto, Takuya,Hiyama, Tamejiro
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supporting information; scheme or table
p. 4447 - 4450
(2010/08/19)
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- Conversion of Weinreb Amides into Benzene Rings Incorporating the Amide Carbonyl Carbon
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Esters, acids and acid chlorides can be converted via the intermediacy of their corresponding Weinreb amides into benzene derivatives that incorporate the original carbonyl carbon as part of the benzene ring. The process involves treatment of the derived Weinreb amides with 3-butenylmagnesium bromide and an allylic Grignard reagent, followed by ring-closing metathesis, dehydration and dehydrogenation. The dehydration-dehydrogenation can be done under acidic conditions with a mixture of TsOH·H2O and DDQ or in two steps with SOCl2/pyridine, followed by treatment with DDQ. Application of the method to carbohydrates provides a convenient route to C-5 aryl pyranosides.
- Clive, Derrick L. J.,Pham, Mai P.
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supporting information; experimental part
p. 1685 - 1690
(2009/07/11)
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- Silver-catalyzed cross-coupling reactions of alkyl bromides with alkyl or aryl Grignard reagents
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Treatment of secondary or tertiary alkyl bromides with alkyl Grignard reagents in the presence of catalytic amounts of silver bromide and potassium fluoride in CH2Cl2 afforded the corresponding cross-coupling products in reasonable yields. Moreover, silver showed catalytic activity for the cross-coupling reactions of alkyl bromides with aryl Grignard reagents.
- Someya, Hidenori,Yorimitsu, Hideki,Oshima, Koichiro
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supporting information; experimental part
p. 3270 - 3272
(2009/08/09)
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- Nitrosonium salts, NO+X- (X = B(3,5-diCF 3Ph)4- or PW12O40 3-), as electrophilic catalysts for alkene activation in arene alkylation and dimerization reactions
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It has been found that in apolar reaction media the nitrosonium cation (NO+) activated alkenes under mild conditions toward electrophilic substitution of arene substrates to yield the alkylated arene with Markovnikov orientation. In the absence of arenes the alkenes react with themselves to yield a mixture of dimeric alkenes. The nitrosonium cation can be dissolved in the reaction medium by using the tetrakis-(bis-(3,5-trifluromethyl)phenyl) borate anion, where upon the reactions occur effectively at 30 °C. Alternatively an insoluble, heterogeneous catalyst was prepared so as to yield a NO+ cation with a polyoxometalate (PW12O403-) anion. This catalyst was generally more effective and selective toward a broader range of substrates at 70 °C. Copyright
- Khenkin, Alexander M.,Neumann, Ronny
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supporting information; scheme or table
p. 11876 - 11877
(2009/02/05)
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- Iron(III) amine-bis(phenolate) complexes as catalysts for the coupling of alkyl halides with aryl Grignard reagents
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Catalytic cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens is achieved using Fe(III) amine-bis(phenolate) halide complexes. The Royal Society of Chemistry.
- Chowdhury, Rajoshree Roy,Crane, Angela K.,Fowler, Candace,Kwong, Philip,Kozak, Christopher M.
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- Nickel-catalyzed cross-coupling reactions of alkyl aryl sulfides and alkenyl alkyl sulfides with alkyl grignard reagents using (Z)-3,3-dimethyl-1,2- bis(diphenylphosphino)but-1-ene as ligand
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A combination of nickel(II) acetylacetonate and (Z)-3,3-dimethyl-1,2- bis(diphenylphosphino)but-1-ene catalyzes cross-coupling reactions of alkyl aryl sulfides and alkenyl alkyl sulfides with alkyl Grignard reagents. Not only primary but also secondary alkyl Grignard reagents can be employed. Georg Thieme Verlag Stuttgart.
- Kanemura, Shigenari,Kondoh, Azusa,Yorimitsu, Hideki,Oshima, Koichiro
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scheme or table
p. 2659 - 2664
(2009/04/05)
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- Iron nanoparticles in the coupling of alkyl halides with aryl Grignard reagents
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Iron nanoparticles, either formed in situ stabilized by 1,6-bis(diphenylphosphino)hexane or polyethylene glycol (PEG), or preformed stabilized by PEG, are excellent catalysts for the cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides bearing β-hydrogens and they also prove effective in a tandem cyclization/cross- coupling reaction. The Royal Society of Chemistry 2006.
- Bedford, Robin B.,Betham, Michael,Bruce, Duncan W.,Davis, Sean A.,Frost, Robert M.,Hird, Michael
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p. 1398 - 1400
(2008/02/03)
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- Amino alcohols as ligands for nickel-catalyzed Suzuki reactions of unactivated alkyl halides, including secondary alkyl chlorides, with arylboronic acids
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Suzuki cross-coupling reactions of an unprecedented array of unactivated primary and secondary alkyl halides (including challenging alkyl chlorides) can be accomplished through the use of nickel/amino alcohol-based catalysts. Both the nickel precatalyst and the amino alcohols (prolinol or trans-2-aminocyclohexanol) are commercially available and air-stable. In view of the remarkable diversity of amino alcohols that are readily accessible, this discovery may open the door to the rapid development of versatile catalysts for a wide range of cross-coupling processes. Copyright
- Gonzalez-Bobes, Francisco,Fu, Gregory C.
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p. 5360 - 5361
(2007/10/03)
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- Iron-phosphine, -phosphite, -arsine, and -carbene catalysts for the coupling of primary and secondary alkyl halides with aryl grignard reagents
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Simple catalysts formed in situ from iron chloride and a wide range of monodentate and bidentate phosphines and arsines have been screened in the coupling of alkyl halides bearing β-hydrogens with aryl Grignard reagents. The best of these show excellent activity, as do catalysts formed in situ with monodentate trialkyl and triaryl phosphite ligands. N-heterocyclic carbene-based precatalysts, either preformed or made in situ, also show excellent performance.
- Bedford, Robin B.,Betham, Michael,Bruce, Duncan W.,Danopoulos, Andreas A.,Frost, Robert M.,Hird, Michael
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p. 1104 - 1110
(2007/10/03)
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- PROCESS FOR PRODUCTION OF AROMATIC COMPOUNDS
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A problem of the present invention is to provide an economical process with minimized toxicity for producing an aromatic compound having a variety of substituents such as various alkyl groups, and the problem is solved by a process for production of an aromatic compound represented by formula (1) below, which comprises reacting a compound represented by formula (2) below with an aromatic magnesium reagent represented by formula (3a) below in the presence of an iron catalyst and a diamine compound: wherein R is an optionally substituted hydrocarbon group or a C 3 - C 10 saturated or unsaturated ring group; A is an optionally substituted C 4 - C 20 aromatic group or an optionally substituted heteroaromatic group; X is a halogen atom or a sulfonic acid ester; and Y 1 is bromine, iodine, chlorine or a carbanion ligand.
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Page/Page column 20-21; 23
(2010/11/24)
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- Stille cross-couplings of unactivated secondary alkyl halides using monoorganotin reagents
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The first catalyst that achieves Stille cross-couplings of secondary (as well as primary) alkyl halides has been developed. The method employs easily handled and inexpensive catalyst components (NiCl2 and 2,2′-bipyridine) and, through the use of monoorganotin reagents, avoids the formation of toxic and difficult-to-remove triorganotin side products. Copyright
- Powell, David A.,Maki, Toshihide,Fu, Gregory C.
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p. 510 - 511
(2007/10/03)
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- Simple iron-amine catalysts for the cross-coupling of aryl Grignards with alkyl halides bearing β-hydrogens
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Mixtures of iron(III) chloride and appropriate amine ligands are active catalysts for the coupling of aryl Grignard reagents with primary and secondary alkyl halide substrates bearing β-hydrogens, under mild and simple reaction conditions. The Royal Society of Chemistry 2005.
- Bedford, Robin B.,Bruce, Duncan W.,Frost, Robert M.,Hird, Michael
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p. 4161 - 4163
(2007/10/03)
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- Alkylation on graphite in the absence of Lewis acids
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Graphite is introduced as a convenient catalyst for alkylation of aromatic compounds and alcohols by benzyl, tertiary alkyl, and secondary alkyl halides in the absence of strong Lewis acids. Primary alkyl halides are not active under the reaction conditions.
- Sereda, Grigoriy A.
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p. 7265 - 7267
(2007/10/03)
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- Iron-Catalyzed Cross-Coupling of Primary and Secondary Alkyl Halides with Aryl Grignard Reagents
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An iron-catalyzed cross-coupling reaction of a primary or secondary alkyl halide with an aryl Grignard reagent proceeds under mild conditions to give the corresponding coupling product in quantitative yield. Copyright
- Nakamura, Masaharu,Matsuo, Keiko,Ito, Shingo,Nakamura, Eiichi
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p. 3686 - 3687
(2007/10/03)
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- Clean-chemistry synthesis of 2-tetralones in a single-stage acylation - Cycloalkylation process
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The preparation of substituted-2-tetralones by direct reaction of a 1-alkene with a substituted phenylacetic acid in a reaction system of trifluoroacetic anhydride (TFAA) and phosphoric acid is described. This single-stage process involves in situ formation of a mixed anhydride of the phenylacetic acid and acylation of the alkene by this species followed by cycloalkylation of the aromatic ring. This is a cleaner approach to the synthesis of 2-tetralones compared to Friedel-Crafts aliphatic acylation-cycloalkylation in that use of thionyl chloride, aluminum trichloride, and a chlorinated hydrocarbon solvent is eliminated. In addition, the atom efficiency is augmented by recovery of the spent TFAA as trifluoroacetic acid (TFA) and conversion of this back to TFAA by dehydration.
- Gray,Smyth
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p. 7113 - 7117
(2007/10/03)
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- An efficient method for aromatic Friedel-Crafts alkylation, acylation, benzoylation, and sulfonylation reactions
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Aromatic electrophilic substitution reactions such as alkylation, acylation, benzoylation, and sulfonylation were studied in the presence of a catalytic amount of Cu(OTf)2 and Sn(OTf)2. Cu(OTf)2 was very efficient for alkylation, acylation, and benzoylation reactions. However, in case of sulfonylation reactions, Sn(OTf)2 gave better results.
- Singh, Ravi P,Kamble, Rajesh M,Chandra, Kusum L,Saravanan,Singh, Vinod K
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p. 241 - 247
(2007/10/03)
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- Montmorillonite clay catalyzed tosylation of alcohols and selective monotosylation of diols with p-toluenesulfonic acid: An enviro-economic route
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An enviro-economic route for tosylation of alcohols and selective monotosylation of diols in good yield directly using p-toluenesulfonic acid together with metal-exchanged montmorillonite instead of p-toluenesulfonyl chloride or p-toluenesulfonic anhydrid
- Choudary, Boyapati M.,Chowdari, Naidu S.,Kantam, Mannepalli L.
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p. 7291 - 7298
(2007/10/03)
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- Novel reductive Friedel-Crafts alkylation of aromatics catalyzed by indium compounds: Chemoselective utilization of carbonyl moieties as alkylating reagents
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Reductive Friedel-Crafts alkylation of aromatics with ketones or aldehydes was characteristically catalyzed by indium compounds in preference to general catalysts like AlCl3 and BF3, where hydrosilanes would play an important role both as a hydride donor and as a co-catalyst. Chemoselective utilization of ketone moieties as alkylating reagents took place even in the presence of halogen, ester or ether moieties which are very susceptible under traditional Friedel-Crafts conditions. Discussion on a plausible intermediate was carried out by some controlled experiments.
- Miyai, Takashi,Onishi, Yoshiyuki,Baba, Akio
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p. 1017 - 1026
(2007/10/03)
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- Detailed Characterization of p-Toluenesulfonic Acid Monohydrate as a Convenient, Recoverable, Safe, and Selective Catalyst for Alkylation of the Aromatic Nucleus
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Alkylation of the aromatic nucleus, an important reaction in industry and synthetic organic chemistry, has traditionally been carried out by the well-known Friedel-Crafts reaction employing Lewis acid catalysts such as AlCl3 and BF3 or by using highly reactive organometallic reagents. Although protic acids such as anhydrous HF and concentrated H2SO4 have also been used in the alkylation of the aromatic nucleus, the notoriously corrosive, highly toxic, and hazardous nature of these agents has precluded their common use under ordinary laboratory conditions. Various organic sulfonic acids have, on occasion, been used as catalysts in Friedel-Crafts alkylations, but to our knowledge the chemistry and the scope of these reactions for common laboratory use have never been exploited in detail. In the present study we have characterized commercially available p-toluenesulfonic acid monohydrate (TsOH) as an efficient catalyst for the intermolecular coupling of the aromatic nucleus with activated alkyl halides, alkenes, or tosylates under mild conditions in an open atmosphere. In comparison to conventional Friedel-Crafts catalysts such as AlCl3, BF3, HF, and concentrated H2SO4, the extent of the formation of undesired products from side reactions such as transalkylation, polymerization, etc. was minimal with the TsOH-catalyzed reaction. The ability to recover and reuse the catalyst from the reaction mixtures, minimal generation of environmentally unfriendly waste, high specificity of the reaction, and the low cost of the catalyst are important advantages of the TsOH catalyst over the other conventional Friedel-Crafts catalysts.
- Mahindaratne, Mathew P. D.,Wimalasena, Kandatege
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p. 2858 - 2866
(2007/10/03)
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- Indium trichloride catalyzed reductive Friedel-Crafts alkylation of aromatics using carbonyl compounds
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Reductive Friedel-Crafts alkylation of aromatics with aldehydes or ketones using chlorodimethylsilane as a hydride source was effectively promoted by a catalytic amount of indium trichloride, whereas a popular type of Friedel-Crafts catalysts showed less effect.
- Miyai, Takashi,Onishi, Yoshiyuki,Baba, Akio
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p. 6291 - 6294
(2007/10/03)
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- Catalysis of Friedel-Crafts Alkylation by a Montmorillonite Doped with Transition-Metal Cations
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Catalysts are obtained by exchange of the interstitial cations in the K10 montmorillonite.They are applied to Friedel-Crafts alkylations with halides, alcohols, and olefins.They are quite effective even with unactivated hydrocarbons.Isomer distribution depends little on the catalyst used.Thermodynamic equilibration does not take place, the reactions appear to be kinetically controlled.Efficiency of the catalysts bears no apparent relation to that of the corresponding Lewis acids under homogeneous conditions, and it depends on the nature of the alkylating agent.Zr(IV) and Ti(IV), in general, give the best results.
- Laszlo, Pierre,Mathy, Arthur
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p. 577 - 586
(2007/10/02)
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- Analytical Applications of 200 MHz PMR Spectroscopy - Isomer Analysis in Tolylcycloalkanes
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Isomer ratios in authentic mixtures of o-, m- and p-xylenes have been quantitatively estimated using aromatic ring methyl signals in 200 MHz PMR spectra.Unknown samples of tolylcycloalkanes, obtained by Friedel-Crafts reaction of toluene with cycloalkene
- Singh, P. K.,Rajeswari, K.,Ranganayakulu, K.
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p. 651 - 653
(2007/10/02)
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- Photochemical Aromatic Cyclohexylation
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Photolysis of cyclohexyl iodide with aromatic compounds led to aromatic cyclohexylation by a process apparently involving a cationic cyclohexyl species.
- Kurz, Michael,Rodgers, Mary
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p. 1227 - 1228
(2007/10/02)
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