444608-64-4Relevant academic research and scientific papers
Stereospecific Iron-Catalyzed Carbon (sp2)-Carbon (sp2) Cross-Coupling of Aryllithium with Vinyl Halides
Chen, Peng,Peng, Xiao-Shui,Wang, Zhi-Yong,Wong, Henry N. C.
supporting information, p. 4385 - 4390 (2021/06/27)
We present herein an efficient synthetic protocol involving iron-catalyzed cross-coupling of organolithium compounds with vinyl halides as key coupling partners. More than 30 examples were obtained with moderate to good yields and high stereoselectivities. The practicality of this method is evidenced by a gram-scale synthesis. In addition, a preliminary mechanistic investigation was also performed.
Palladium-catalyzed decarboxylative coupling of α,β-unsaturated carboxylic acids with aryl tosylates
Zhang, Wei,Chen, Gairong,Wang, Kaikai,Xia, Ran
, (2019/04/27)
We report a general method for selective cross-coupling of α,β-unsaturated carboxylic acids with aryl tosylates enabled by versatile Pd(II) complexes. This method features the general cross-coupling of ubiquitous α,β-unsaturated carboxylic acids by decarboxylation. The transformation is characterized by its operational simplicity, the use of inexpensive, air-stable Pd(II) catalysts, scalability and wide substrate scope. The reaction proceeds with high trans selectivity to furnish valuable (E)-1,2-diarylethenes.
Rapid Access to Ortho-Alkylated Vinylarenes from Aromatic Acids by Dearomatization and Tandem Decarboxylative C-H Olefination/Rearomatization
Tsai, Hung-Chang,Huang, Yen-Hsiang,Chou, Chih-Ming
, p. 1328 - 1332 (2018/03/09)
A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birch reduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C-H olefination followed by rearomatization to deliver ortho-alkylated vinylarene. Mechanistic studies suggest that a Pd/Ag bimetallic catalytic system is important in the tandem decarboxylative C-H olefination/rearomatization step.
O -Iodoxybenzoic acid mediated generation of aryl free radicals: Synthesis of stilbenes through C-C cross-coupling with β-nitrostyrenes
Wagh, Ganesh,Autade, Snehalata,Patil, Pravin C.,Akamanchi, Krishnacharya G.
, p. 3301 - 3309 (2018/03/06)
The generation of an aryl free radicals in the presence of nitrostyrenes through a combination of aryl hydrazines and o-iodoxybenzoic acid led to the synthesis of stilbenes by forming a new carbon-carbon bond after subsequent elimination of a nitrosyl radical. The symmetrical and unsymmetrical stilbenes with excellent E-selectivity were synthesized in good yields, with advantages of broad substrate scope and transition metal free, mild reaction conditions, under an open atmosphere in a short reaction time. A free radical mediated mechanism was postulated and supported by radical trapping experiments. Application of the developed methodology is demonstrated through a simple, two step synthesis of resveratrol, a valuable stilbenoid for anticancer and neurological studies via its prodrug E-1,3-dimethoxy-5-(4-methoxystyryl)benzene.
Rhodium-catalyzed cross-coupling of vinylarenes with arylaluminum reagents in the presence of ketones
Tanaka, Shota,Mori, Atsunori
supporting information, p. 1167 - 1171 (2014/03/21)
Rhodium-catalyzed addition/elimination of arylaluminum reagents with vinylarenes was achieved to obtain stilbene derivatives. The reaction of diethyl(phenyl)aluminum with styrene in the presence of the chloro(1,5- cyclooctadiene)rhodium(I) dimer, [RhCl(cod)]2, and diisopropyl ketone (2,4-dimethyl-3-pentanone) as an additive occurred to give (E)-stilbene in quantitative yield. The use of other arylaluminum reagents afforded β-arylated products in good to excellent yields. This reaction was found to be promoted by ketones as additives, which are reduced to the corresponding alcohols, as confirmed by analysis of the crude reaction mixture by 1H NMR spectroscopy. Ketones play a key role in the Rh-catalyzed addition/elimination of arylaluminum reagents with vinylarenes, which leads to 1,2-diarylethenes in excellent yields; in the absence of ketones, the same products are delivered in only moderate yields. Reaction of diethyl(phenyl) aluminum and styrene with [RhCl(cod)]2 in the presence of diisopropyl ketone gives stilbene in a quantitative yield. Copyright
Rhodium-Catalyzed Cross-Coupling of Vinylarenes with Arylaluminum Reagents in the Presence of Ketones
Tanaka, Shota,Mori, Atsunori
supporting information, p. 1167 - 1171 (2015/10/05)
Rhodium-catalyzed addition/elimination of arylaluminum reagents with vinylarenes was achieved to obtain stilbene derivatives. The reaction of diethyl(phenyl)aluminum with styrene in the presence of the chloro(1,5-cyclooctadiene)rhodium(I) dimer, [RhCl(cod)]2, and diisopropyl ketone (2,4-dimethyl-3-pentanone) as an additive occurred to give (E)-stilbene in quantitative yield. The use of other arylaluminum reagents afforded β-arylated products in good to excellent yields. This reaction was found to be promoted by ketones as additives, which are reduced to the corresponding alcohols, as confirmed by analysis of the crude reaction mixture by 1H NMR spectroscopy.
Feeding the Heck reaction with alcohol: One-pot synthesis of stilbenes from aryl alcohols and bromides
Colbon, Paul,Barnard, Jonathan H.,Purdie, Mark,Mulholland, Keith,Kozhevnikov, Ivan,Xiao, Jianliang
supporting information; scheme or table, p. 1395 - 1400 (2012/07/03)
Aryl alcohols are employed as feedstock for the Heck reaction. Keggin-type heteropolyacids catalyse the selective dehydration of the alcohols to styrenes, which, in one-pot, undergo palladium-catalysed Heck arylation with aryl bromides, affording broadly functionalised stilbenes. The choice of solvent is critical for the cascade dehydration-Heck reaction, with electron-rich aryl alcohols preferring a basic medium while electron-deficient ones demanding solvents of lower basicity. Copyright
Selective cine substitution of 1-arylethenyl acetates with arylboron reagents and a diene/rhodium catalyst
Yu, Jung-Yi,Shimizu, Ryosuke,Kuwano, Ryoichi
supporting information; experimental part, p. 6396 - 6399 (2010/11/17)
When the crowd says Bo: A carbon-carbon bond is selectively formed at the β position of 1- arylethenyl acetate when the alkenyl substrate is reacted with arylboronic acids in the presence of a cycloocta-1,5-diene/rhodium catalyst. The choice of the ligand is crucial for the unusual cine substitution. Copyright
Studies on the 1,2-migrations in Pd-catalyzed negishi couplings with JosiPhos ligands
Lindhardt, Anders T.,G?gsig, Thomas M.,Skrydstrup, Troels
supporting information; experimental part, p. 135 - 143 (2009/04/07)
(Chemical Equation Presented) We report an initial investigation with the goal of determining the factors that control the 1,2-migration in the Negishi cross-coupling, which is promoted by palladium catalyst systems generated with JosiPhos ligands. Severa
Low-valent niobium-mediated synthesis of indenes: Intramolecular coupling reaction of CF3 group with alkene C-H bond
Fuchibe, Kohei,Mitomi, Ken,Akiyama, Takahiko
, p. 24 - 25 (2007/10/03)
CF3 group of o-alkenyl-α,α,α-trifluorotoluenes underwent intramolecular coupling reaction with the alkene C-H bond under NbCl5/LiAlH4 system. Substituted indenes were obtained in good yields. Copyright
