- Thianthrenation-enabled α-arylation of carbonyl compounds with arenes
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The Pd-catalyzed α-arylation of carbonyl compounds with simple arenes enabled by site-selective thianthrenation has been demonstrated. This onepot process using thianthrenium salts as the traceless arylating reagents features mild conditions and a broad substrate scope. In addition, this protocol could also tolerate the heterocyclic carbonyl compounds and complex bioactive molecules, which is appealing for medicinal chemistry.
- Huang, Yu-Hao,Nie, Xiao-Xue,Wang, Peng
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supporting information
p. 7716 - 7720
(2020/11/02)
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- Method for preparing substituted aryl ketone by ketone arylation (by machine translation)
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The invention provides a method, for preparing substituted aryl ketone, by using a nitrogen heterocyclic carbene catalyst, with a saturated nitrogen heterocyclic carbene structure in an oxygen-containing atmosphere at, through α - catalysis of a nitrogen heterocyclic carbene structure, in a nitrogen heterocyclic carbene catalyst with a saturated nitrogen heterocyclic carbene structure under an alkaline condition, in an oxygen-containing atmosphere and can efficiently prepare various substituted, aryl ketones α - under the condition of containing an oxygen. atmosphere. (by machine translation)
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Paragraph 0078-0081; 0090-0093
(2020/03/05)
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- Two-Step One-Pot Synthesis of Unsymmetrical (Hetero)Aryl 1,2-Diketones by Addition-Oxygenation of Potassium Aryltrifluoroborates to (Hetero)Arylacetonitriles
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An efficient one-pot two-step procedure for the synthesis of unsymmetrical (hetero)aryl 1,2-diketones has been developed. The reaction proceeds through a palladium-catalyzed nucleophilic addition of potassium aryltrifluoroborates to aliphatic nitriles followed by a copper-catalyzed aerobic benzylic C–H oxygenation using molecular oxygen as a green oxidant. This represents the first example of the direct synthesis of unsymmetrical diaryl 1,2-diketones from arylacetonitriles. This method utilizes inexpensive, stable, nontoxic, and readily available starting materials, is highly effective in the presence of both electron-rich and electron-poor nitriles and aryltrifluoroborates, and tolerates a wide variety of functional groups. The synthetic utility of this transformation was shown by increasing the scale of the reaction and by carrying out the one-pot protocol for the preparation of quinoxaline and benzimidazole derivatives. A plausible reaction mechanism has also been proposed.
- Kumar, Yogesh,Jaiswal, Yogesh,Kumar, Amit
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p. 494 - 505
(2018/02/09)
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- Novel bisamide palladium(II) pincer complexes: effective catalysts in α-arylation of ketones
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Three benzenedicarboxamide ligands (L) were designed and synthesized, and each was used to prepare a palladium(II) complex Pd(L)Br and Pd(L)(OAc). These NCN pincer complexes were used to catalyze the α-arylations of a variety of ketones with aryl chlorides or bromides in various solvents, and moderate-to-excellent yields were obtained (up to 95%). Further research showed that unactivated and sterically hindered aryl halides and ketones are also suitable substrates for the synthesis of α-arylation. Graphical Abstract: [Figure not available: see fulltext.].
- Kai, Wang,Liu, Dabin,Qian, Hua,Ye, Zhiwen
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p. 443 - 450
(2017/07/12)
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- Nickel catalyzed α-arylation of ketones with aryltrimethylammonium triflates
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Nickel-catalyzed α-arylation of ketones involving aromatic C-N cleavage has been accomplished. Intermolecular coupling of aromatic ketones with a variety of aryltrimethylammonium triflates was achieved in the presence of Ni(COD)2, IPr·HCl, and LiOBut, giving α-arylated ketones in reasonable to excellent yields.
- Li, Jing,Wang, Zhong-Xia
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p. 7579 - 7584
(2016/08/16)
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- Selective Metal-Free Deoxygenation of Unsymmetrical 1,2-Dicarbonyl Compounds by Chlorotrimethylsilane and Sodium Iodide
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For the first time, the combination of chlorotrimethylsilane with NaI is used as a selective reducting system toward 1,2-diketones. This combination is successfully evaluated with several unsymmetrically benzil derivatives, which are reduced in good yield
- Yuan, Ling-Zhi,Renko, Dolor,Khelifi, Ilhem,Provot, Olivier,Brion, Jean-Daniel,Hamze, Abdallah,Alami, Mouad
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supporting information
p. 3238 - 3241
(2016/07/14)
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- Copper-catalyzed base-accelerated direct oxidation of C-H bond to synthesize benzils, isatins, and quinoxalines with molecular oxygen as terminal oxidant
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We describe herein an efficient and general copper (II)-catalyzed base-accelerated oxidation of the C-H bond to synthesize benzils and isatins. With similar oxidation system an efficient one-pot procedure for the synthesis of quinoxaline derivatives was realized. The two protocols feature using molecular oxygen as terminal oxidant, low catalyst loading, wide substrate scope, and high functional-group tolerance.
- Yu, Jing-Wen,Mao, Shuai,Wang, Yong-Qiang
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p. 1575 - 1580
(2015/03/14)
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- General and mild Ni0-catalyzed α-arylation of ketones using aryl chlorides
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A general methodology for the α-arylation of ketones using a nickel catalyst has been developed. The new well-defined [Ni(IPr)(cin)Cl] (1c) pre-catalyst showed great efficiency for this transformation, allowing the coupling of a wide range of ketones, including acetophenone derivatives, with various functionalised aryl chlorides. This cinnamyl-based Ni-N-heterocyclic carbene (NHC) complex has demonstrated a different behaviour to previously reported NHC-Ni catalysts. Preliminary mechanistic studies suggest a Ni0/NiII catalytic cycle to be at play.
- Fernndez-Salas, Jos A.,Marelli, Enrico,Cordes, David B.,Slawin, Alexandra M.Z.,Nolan, Steven P.
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supporting information
p. 3906 - 3909
(2015/10/19)
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- Palladium-catalyzed α-arylation of arylketones at low catalyst loadings
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A general catalytic protocol for the α-arylation of aryl ketones has been developed. It involves the use of a preformed, bench-stable Pd-N-heterocyclic carbene pre-catalyst bearing IHept as an ancillary ligand, and allows the coupling of various functiona
- Marelli, Enrico,Corpet, Martin,Davies, Sian R.,Nolan, Steven P.
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supporting information
p. 17272 - 17276
(2015/02/05)
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- Carbene adduct of cyclopalladated ferrocenylimine catalyzed α-arylation of ketones with aryl chlorides or bromides
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Carbene adduct of cyclopalladated ferrocenylimine exhibited highly catalytic activity for the α-arylation of ketones with aryl halides. The corresponding products were obtained in moderate to excellent yields. Such protocol was applied to various ketones and a broad scope of aryl halides including aryl chlorides, bromides as well as unactivated and sterically hindered aryl halides.
- Zhang, Jinli,Yang, Xueqian,Cui, Xiuling,Wu, Yangjie
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experimental part
p. 8800 - 8807
(2011/12/02)
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- (N-Heterocyclic Carbene)-Pd-catalyzed anaerobic oxidation of secondary alcohols and domino oxidation-arylation reactions
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The use of commercially available (SIPr)Pd(cinnamyl)Cl (SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene) as a precatalyst for the anaerobic oxidation of secondary alcohols is described. The use of this complex allows for a drastic reduction in the reaction times and catalyst loading when compared to the unsaturated counterpart. This catalytic system is compatible with the use of microwave dielectric heating, decreasing even further catalyst loading and reaction times. Domino Pd-catalyzed oxidation-arylation reactions of secondary alcohols are also presented.(Figure Presented)
- Landers, Brant,Berini, Christophe,Wang, Chao,Navarro, Oscar
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experimental part
p. 1390 - 1397
(2011/05/02)
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- p-Toluenesulfonic acid-promoted selective functionalization of unsymmetrical arylalkynes: a regioselective access to various arylketones and heterocycles
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Regioselective hydration of a wide range of internal alkynes has been afforded in high to good yields by using PTSA in EtOH. The scope of the reaction of alkynes has been delineated. Arylaliphatic alkynes and diarylalkynes were regioselectively hydrated in good to excellent yields and short reaction times when the reaction was achieved under microwave irradiation. Moreover, diarylalkynes, arylenynes as well as diaryldiynes bearing a methoxy- or a thiomethyl substituent on the ortho position underwent a regioselective 5-endo-dig-cyclization to give a variety of 2-aryl- and 2-styrylbenzofuran or benzothiphene derivatives. We believe that, this new environmentally metal-free procedure combined to microwave irradiation would be in importance in the search of green laboratory-scale synthesis.
- Jacubert, Maud,Provot, Olivier,Peyrat, Jean-Fran?ois,Hamze, Abdallah,Brion, Jean-Daniel,Alami, Mouad
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experimental part
p. 3775 - 3787
(2010/07/04)
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- Investigations concerning the COX/5-LOX inhibiting and hydroxyl radical scavenging potencies of novel 4,5-diaryl isoselenazoles
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The aim of this study was to investigate 4,5-diaryl isoselenazoles as multiple target non-steroidal anti-inflammatory drugs (MTNSAIDs) which can intervene into the inflammatory processes via different mechanisms of action creating a new class of compounds
- Scholz, Michael,Ulbrich, Holger K.,Dannhardt, Gerd
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p. 1152 - 1159
(2008/09/20)
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- Application of the catalytic friedel-crafts acylation reaction and regioselectivity correlations
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A correlation was found between electronic properties and regioselectivity in the Friedel-Crafts reaction of substituted phenylacetic and benzoic acids with anisole, utilising substoichiometric (down to 1 mol%) amounts of catalyst. Relative reactivities of selected catalysts for this reaction were also studied. Georg Thieme Verlag Stuttgart.
- Wilkinson, Mark C.,Saez, Fabienne,Wei, Lee Hon
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p. 1063 - 1066
(2007/10/03)
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- Rapid microwave assisted hydration of internal arylalkynes in the presence of PTSA: an efficient regioselective access to carbonyl compounds
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A metal-free procedure for the regioselective hydration of internal arylalkynes under microwave irradiation is described. The reaction promoted by PTSA takes place rapidly in EtOH and regioselectively afforded in good yields various carbonyl compounds 2.
- Le Bras, Ga?lle,Provot, Olivier,Peyrat, Jean-Fran?ois,Alami, Mouad,Brion, Jean-Daniel
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p. 5497 - 5501
(2007/10/03)
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- Modulation of lifetimes and diastereomeric discrimination in triplet- excited substituted butane-1,4-diones through intramolecular charge-transfer quenching
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Triplet lifetimes have been determined for the diastereomers of a broad set of butane-1,4-dione derivatives (1-3). A remarkable dependence of lifetimes on conformational preferences is revealed in that the lifetimes are shorter for the meso diastereomers of 1-3 than those for the racemic ones. The intramolecular β-phenyl quenching is promoted in the case of meso diastereomers by virtue of the gauche relationship between the excited carbonyl group and the β-aryl ring, while a distal arrangement in the lowest energy conformation (H-anti) in racemic diastereomers prevents such a deactivation. The involvement of charge transfer in the intramolecular β- phenyl quenching is suggested by the correlation of the triplet lifetimes of the meso diastereomers of compounds 2 with the nature of the substituent on the β-phenyl rings. In the case of racemic diastereomers, p-methoxy substitution on the β-phenyl ring (2-OCH3, 3-OCH3) also led to a decrease of the triplet lifetimes when compared to those of the nonsubstituted compounds (2-H, 3-H). This shortening is accounted for by the deactivation of a small proportion of the excited molecules through β-phenyl quenching. In addition to the above factors, the lifetimes in the case of meso diastereomers can further be controlled by increasing the energy spacing between the T1 and T2 states, since β-phenyl quenching occurs from the latter for compounds 2 and 3. Through a rational conformational control, a surprisingly long triplet lifetime (300 ns) has been measured for the first time for a purely n,π* triplet-excited β-phenylpropiophenone dimer (1- rac).
- Moorthy,Monahan,Sunoj,Chandrasekhar,Bohne
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p. 3093 - 3103
(2007/10/03)
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- General and efficient insertions of carbons carrying aryl and heteroaryl groups: Synthesis of α-Aryl- And α-heteroaryl-substituted ketones
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Anions formed from the lithiation of a variety of 1-(arylmethyl)- and 1-(heteroarylmethyl)-benzotriazoles 1 with n-BuLi underwent addition to aliphatic and aromatic aldehydes and cyclic and acyclic ketones. Subsequent in situ thermal rearrangements of the intermediates in the presence of zinc bromide provided one-carbon chain-extended or ring-expanded α-aryl- and α-heteroaryl-substituted ketones 2 in moderate to excellent yields in simple one-pot operations with excellent regioselectivity in most cases. Substituent effects on the relative migration rates were investigated in the insertion reactions of 1-(4-methoxybenzyl)benzotriazole (1e) with XC6H4-COPh. The small and negative Hammett ρ+ value (-0.92) suggested that the rearrangements proceed via early, reagent-like, electron deficient transition states.
- Katritzky, Alan R.,Toader, Dorin,Xie, Linghong
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p. 7571 - 7577
(2007/10/03)
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