- Nickel-Catalyzed Arylation of C(sp3)-O Bonds in Allylic Alkyl Ethers with Organoboron Compounds
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A nickel-catalyzed cross-coupling of allylic alkyl ethers with organoboron compounds through the cleavage of the inert C(sp3)-O(alkyl) bonds is described. Several types of allylic alkyl ethers can be coupled with various boronic acids or their derivatives to give the corresponding products in good to excellent yields with wide functional group tolerance and excellent regioselectivity. The gram-scale reaction and late-stage modification of biologically active compounds further prove the practicality of this synthetic method.
- Li, Xiaowei,Li, Yuxiu,Zhang, Zhong,Shi, Xiaolin,Liu, Ruihua,Wang, Zemin,Li, Xiangqian,Shi, Dayong
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supporting information
p. 6612 - 6616
(2021/09/02)
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- Bis-quinoline-2-carboxylic acid Copper Salt as an Efficient Catalyst for Synthesis of Aryl Olefins by Heck Reaction
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Abstract: A bis-quinoline-2-carboxylic acid copper salt as a single crystal was prepared and characterized by X-ray single crystal analysis. The crystal as a catalyst was applied to the Mizoroki–Heck coupling reaction between arylboronic acids and α-olefins. A series of diarylethenes and aryl olefins were synthesized with good to excellent yields at room temperature. The catalytic system exhibited good functional group tolerance and low pollution. Graphic Abstract: A bis-quinoline-2-carboxylic acid copper salt as a single crystal was prepared and characterized by X-ray single crystal analysis. The crystal as a catalyst was applied to the Mizoroki–Heck coupling reaction between arylboronic acids and α-olefins[InlineMediaObject not available: see fulltext.].
- Zuo, Minghui,Li, Zhuofei,Fu, Wanyong,Guo, Rui,Hou, Chuanfu,Guo, Weihao,Sun, Zhizhong,Chu, Wenyi
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p. 3217 - 3223
(2019/07/17)
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- Nickel-Catalyzed Direct Coupling of Allylic Alcohols with Organoboron Reagents
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The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni(cod)2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or arylboronic acids turned out to be applicable to this catalytic system. The present method does not require the use of ligands for stabilizing the nickel catalyst in most cases or additional activators for activation of allylic alcohols.
- Wang, Gaonan,Gan, Yi,Liu, Yuanhong
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p. 916 - 920
(2018/09/22)
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- Iron-Catalyzed Remote Arylation of Aliphatic C-H Bond via 1,5-Hydrogen Shift
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Catalytic amounts of an iron(III) salt and a N-heterocyclic carbene ligand catalyze the arylation of 2-iodoalkylarenes with diphenylzinc selectively at the C-H bond of the alkyl side chain. Several lines of evidence suggest that the iron catalyst reacts with the aryl iodide moiety of the substrate to generate an aryliron intermediate that behaves in a radical manner and cleaves the aliphatic C-H bond through 1,5-hydrogen transfer; the resulting alkyliron intermediate undergoes reductive elimination to give the arylated product.
- Zhou, Bingwei,Sato, Hiroki,Ilies, Laurean,Nakamura, Eiichi
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- Chemo- and regioselective reductive deoxygenation of 1-en-4-yn-ols into 1,4-enynes through FeF3 and TfOH co-catalysis
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We report chemo- and regioselective direct reductive deoxygenation of 1-en-4-yn-3-ols into 1,4-enynes through FeF3 and TfOH cooperative catalysis under NBSH-mediated conditions. Further, we show the efficient synthesis of a pharmaceutically significant 1,4-enyne. The present methodology can also be used for chemo- and regioselective direct deoxygenation of other alcohols.
- Yang, Zonglian,Kumar, Rapolu Kiran,Liao, Peiqiu,Liu, Zhaohong,Li, Xingqi,Bi, Xihe
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supporting information
p. 5936 - 5939
(2016/05/24)
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- Cross-coupling of N-allylic sulfonimides with organozinc reagents at room temperature
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An efficient cross-coupling reaction of N-allylic sulfonimides with organozinc reagents has been developed. In the presence of 1 mol-% of Pd 2(dba)3, a range of N-allylic sulfonimides smoothly couple with various organozinc reagents at room temperature to give the corresponding (E)-alkene products in moderate to excellent yields and with good to exclusive α-selectivity. It is noteworthy that allyl ether, benzyl ether, and ester are tolerated under the reaction conditions. A range of N-allylic sulfonimides smoothly couple with various organozinc reagents in the presence of 1 mol-% of Pd2(dba)3 at room temperature to give the corresponding (E)-alkene products in moderate to excellent yields and with good to exclusive α-selectivity.
- Tang, Xiang-Ling,Wu, Zhao,Li, Man-Bo,Gu, Yonghong,Tian, Shi-Kai
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p. 4107 - 4109
(2012/09/08)
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- Regioselective and stereospecific cross-coupling of primary allylic amines with boronic acids and boronates through palladium-catalyzed C-N bond cleavage
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The NH2 group serves as an effective leaving group in the palladium-catalyzed regioselective and stereospecific title reaction (see scheme). The reaction works well with aryl- and alkenylboronic acids and aryl-, alkenyl-, allyl-, and benzylboronates, and complete transfer of chirality has been achieved when using α-chiral primary allylic amines as the allylic electrophiles. Copyright
- Li, Man-Bo,Wang, Yong,Tian, Shi-Kai
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supporting information; experimental part
p. 2968 - 2971
(2012/04/18)
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- Cobalt-catalyzed benzylzincation of alkynes
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Chemical Equotion Present Carbometalation: Cobalt salts catalyze benzylzincation of alkynes to afford benzylated multisubstituted alkenes with high regio- and stereoselectivity. The scope of the reaction is wide enough to apply unfunctionalized alkynes as well as arylacetylenes. The reaction offers a new route to the regio- and stereoselective synthesis of an estrogen receptor antagonist (see scheme).
- Murakami, Kei,Yorimitsu, Hideki,Oshima, Koichiro
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experimental part
p. 7688 - 7691
(2010/09/10)
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- A versatile catalyst system for suzuki-miyaura cross-coupling reactions of C(sp2)-tosylates and mesylates
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Figure Presented A catalyst system for the Suzuki-Miyaura cross-coupling reactions of aryl and vinyl tosylates and mesylates has been developed. This catalyst displays excellent functional group tolerance and allows the coupling of heteroarylboronic acids
- Bhayana, Brijesh,Fors, Brett P.,Buchwald, Stephen L.
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supporting information; experimental part
p. 3954 - 3957
(2009/12/03)
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- Palladium(0)-catalyzed direct cross-coupling reaction of allylic alcohols with aryl- and alkenylboronic acids
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Allylic alcohols can be used directly for the palladium(0)-catalyzed allylation of aryl- and alkenylboronic acids with a wide variety of functional groups. A triphenylphosphine-ligated palladium catalyst turns out to be most effective for the cross-coupling reaction and its low loading (less than 1 mol%) leads to formation of the coupling product in high yield. The Lewis acidity of the organoboron reagents and poor leaving ability (high basicity) of the hydroxyl group are essential for the cross-coupling reaction. The reaction process is atom-economical and environmentally benign, because it needs neither preparation of allyl halides and esters nor addition of stoichiometric amounts of a base. Furthermore, allylic alcohols containing another unsaturated carbon-carbon bond undergo arylative cyclization reactions leading to cyclopentane formation. The Royal Society of Chemistry.
- Tsukamoto, Hirokazu,Uchiyama, Tomomi,Suzuki, Takamichi,Kondo, Yoshinori
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supporting information; experimental part
p. 3005 - 3013
(2009/02/03)
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- Palladium(0)-catalyzed direct cross-coupling reaction of allyl alcohols with aryl- and vinyl-boronic acids
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Allyl alcohols can be directly used for the palladium-catalyzed allylation of aryl- and vinyl-boronic acids without the aid of a base.
- Tsukamoto, Hirokazu,Sato, Masanori,Kondo, Yoshinori
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p. 1200 - 1201
(2007/10/03)
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- Modern Friedel-Crafts chemistry. Part-26. A facile synthesis of trans-2-methyl-1-phenylindan via rearranged intramolecular cyclialkylation of 1,2-diphenyl-2-methyl-2-propanol under Friedel-Crafts conditions
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1,2-Diphenyl-2-methyl-2-propanol (1) was prepared by two alternative Grignard methods. Treatment of 1 with AlCl3, AlCl3/CH 3NO2 or K10 clay catalyst in benzene, toluene of dichloromethane solvent at varying temperatures for varying times gave trans-2-methyl-1-phenylindan (4) as sole or major product. Side products including isomeric alkenes 7 and 8, isomeric chlorides 9 and 10, isomeric triarylated isobutanes 11-14, 1-methyl-3-phenylindan (5) and 2-methyl-1-phenylindene (6) were also detected by GC-MS technique. Mechanistic interpretations and explanatory comments are offered.
- Khalaf, Ali A.,Albar, Hassan A.
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p. 518 - 521
(2007/10/03)
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- A general and stereoselective method for synthesis of tri- and tetrasubstituted alkenes
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A convenient, general and stereoselective synthesis of trisubstituted alkenes and tetrasubstituted alkenes containing a cyanide function as well as trisubstituted episulphides have been elaborated. Methodology described for the preparation of these compounds is based on the corresponding readily available selenophosphates 1 and thiophosphates 2.
- Macia?giewicz,Dybowski,Skowrońska
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p. 6057 - 6066
(2007/10/03)
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- A new synthesis of tri- and tetrasubstituted olefins based on thio- and selenophosphates
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Stereoselective synthesis of tri- and tetrasubstituted functionalized olefins and new phosphates bearing functionalized cyclic substituent has been developed using thiophosphates and selenophosphates as key intermediates.
- Skowronska,Maciagiewicz,Dybowski,Krawczyk,Owsianik
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p. 409 - 412
(2007/10/03)
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- Allyl- And Benzylindium Reagents. Carboindation of Carbon-Carbon and Carbon-Nitrogen Triple Bonds
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The reaction of unactivated simple terminal alkynes 1 with allylindiums in THF proceeded smoothly to give the corresponding allylation products 2 in good to high yields. This result is in marked contrast to that of the reaction carried out in DMF, where the allylation of unactivated alkynes was very sluggish. The allylic group of the reagent was attached to the internal carbon of the triple bond, and indium was attached to the less substituted terminal carbon, except for the case of TMS substituted acetylenes 1j and 1k in which the allyl group went to the less substituted carbon of the triple bond. The reaction of unactivated simple terminal and certain internal acetylenes with benzylindium in THF proceeded smoothly to afford the corresponding benzylation products 18 in good to high yields. The benzyl group was attached to the less substituted unhindered carbon of the triple bond, and indium was attached to the more sterically congested carbon. The reaction of activated nitriles 3 with allylindiums in THF at 70°C gave the corresponding allylationenamination products 4 in high to excellent yields. This reaction provides a useful method for the synthesis of highly functionalized enamines, which are not easily available via conventional methods. The mechanisms on the above three indation reactions are discussed.
- Fujiwara, Naoya,Yamamoto, Yoshinori
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p. 4095 - 4101
(2007/10/03)
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- Synthesis, structural characterization, and reactivity of zirconium complexes containing trimethylenemethane-based ligands
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General synthetic routes to zirconium metallocene-like complexes containing derivatives of the dianionic trimethylenemethane (TMM) ligand are presented. One approach consists of reacting the dilithium salts of TMM, tribenzylidenemethane (TBM), tert-butylt
- Rodriguez, George,Bazan, Guillermo C.
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p. 343 - 352
(2007/10/03)
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- Regioselectivity in the Addition of Carbon Nucleophiles to 1-Fluoro and 1,1-Difluoro ?-Allylpalladium Complexes
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Attack on 1-fluoro and 1,1-difluoro ?-allylpalladium complexes by stabilized carbon nucleophiles occurs preferentially at the nonfluorinated terminus, whereas the attack of a nonstabilized carbon nucleophile takes place at the fluorinated end.
- Shi, Guo-quiang,Huang, Xian-hai,Zhang, Fang-Jiang
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p. 6305 - 6308
(2007/10/02)
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- Nucleophilic addition to coordinated polyenes: A novel method for the liberation of the trimethylenemethane ligand involving C-C bond formation
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Reaction of (trimethylenemethane)Fe(CO)3 with carbon nucleophiles, followed by protonation yields the corresponding methallylated nucleophile in good yield. Products which incorporate carbonyl ligands are also observed.
- Donaldson,Hossain
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p. 4107 - 4110
(2007/10/02)
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- Y-CONJUGATED DIANIONS: A COMPARISON BETWEEN THE 1,1-DIBENZYLETHYLENE AND DIPHENYLACETONE-DERIVED DIANIONS
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The lithium salts of the two title dianions have been synthesised and investigated by 1H and 13C n.m.r. spectroscopy.Whereas the dibenzylidenemethylenemethane dianion salt exists exclusively in the exo,exo conformation, its oxa-analogue is a mixture of two isomers, exo,endo and a symmetrical form, probably exo,exo.The benzyl α,β-CC bond rotation barrier in the ketone dianion salt in THF is 10.8 +/- 0.5 kcal mol-1.The phenyl rotation barrier in the hydrocarbon dianion salt is similar (10.9 kcal mol-1), as are the charge distributions in the benzylidene groups of the two dianions.
- Wilhelm, Dieter,Clark, Timothy,Rague Schleyer, Paul von
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p. 915 - 920
(2007/10/02)
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- THE STEREOCHEMISTRY OF THE DIBENZYLIDENE-ETHYLENE DIANION
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Quench reactions, 13C nmr spectra and MNDO molecular orbital calculations all suggest the title dianion to prefer the exo,exo-conformation, like the 1,3-diphenyl allyl anion, but in contrast to 2-substituted 1,3-diphenyl allyl anions.
- Wilhelm, Dieter,Clark, Timothy,Rauge Schleyer, Paul von
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p. 3985 - 3988
(2007/10/02)
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- Conformations and Rotational Barriers of 1,3-Diphenylallyllithium Compounds
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The phenyl substituents of the 1,3-diphenylallyl anions 10 (gegenion lithium, solvent tetrahydrofuran) can exist in the exo,exo-, endo,exo- and/or endo,endo-conformations.We have investigated the influence of substituents R at C2 on the equilibria of these solvent separated ion pairs.While 10a (R = H) is the only one to exist predominantly in the exo,exo-conformation, and in 10b and c (R = CH3 and CN, respectively) the endo,exo-conformers predominate, in 10d, e and f (R = C2H5, C6H5 and iPr, respectively) there is increasing preference for the endo,endo-conformation, which in 10g (R = tBu) is the dominant (>/= 95percent) conformation.A vast congestion in the endo,endo-conformation is avoided by a rotation of the phenyl rings out of the plane of the allyl carbon atoms, and an expansion of the sp2 angles in the allyl moiety.The rotational barriers around the allyl anion bonds decrease from 19.1 kcal*mol-1 (10a) to 12.5 kcal*mol-1 (10f).Since this trend parallels to the above mentioned shift of the equilibria, it is due to ground state effects.The rotational barriers are only slightly (10a,b) if at all influenced by gegenion effects, which is in sharp contrast to the parent allyl "anion".Therefore, the rotational barriers of the allyl anions 10 are qualified for a comparison with the corresponding radicals and cations.Furthermore, with ΔG(excit)273 deg C = 19.1 kcal*mol-1 as a lower limit value for the rotational barrier of the parent allyl anion, one can estimate that the true value of this species must be close to barriers calculated with STO-3G and 4-3l-G programs (ca. 26 kcal*mol-1).
- Boche, Gernot,Buckl, Klaus,Martens, Diether,Schneider, Dieter R.
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p. 1135 - 1171
(2007/10/02)
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