- Palladium-catalyzed reaction of γ-silylated allyl acetates proceeding through 1,2-shift of a substituent on silicon
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The palladium-catalyzed reaction of γ-silylated allyl acetates with water in the presence of CsF induces a previously unprecedented 1,2-shift of a substituent on silicon to produce allylsilanes in situ. The catalytic activity of the palladium increased when using an electron-poor phosphine ligand possessing fluorinated substituents. Further investigation of the reaction revealed that the approximate order of the migratory aptitude of groups from silicon was PhC≡C, allyl > Bn > Ph, vinyl > alkyl (Me, Et). A density functional theory study was employed to explore the reaction mechanism. Finally, the Hosomi–Sakurai-type allylation of aldehydes with in situ-generated α,γ-disubstituted allylsilanes was also investigated.
- Horino, Yoshikazu,Ishibashi, Mayo,Nakasai, Kosuke,Korenaga, Toshinobu
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- Cross-coupling reaction of allylic ethers with aryl Grignard reagents catalyzed by a nickel pincer complex
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A cross-coupling reaction of allylic aryl ethers with arylmagnesium reagents was investigated using β-aminoketonato- and β-diketiminato-based pincer-type nickel(II) complexes as catalysts. An β-aminoketonato nickel(II) complex bearing a diphenylphosphino group as a third donor effectively catalyzed the reaction to afford the target cross-coupled products, allylbenzene derivatives, in high yield. The regioselective reaction of a variety of substituted cinnamyl ethers proceeded to give the corresponding linear products. In contrast, α- and γ-alkyl substituted allylic ethers afforded a mixture of the linear and branched products. These results indicated that the coupling reaction proceeded via a π-allyl nickel intermediate.
- Hashimoto, Toru,Funatsu, Kei,Ohtani, Atsufumi,Asano, Erika,Yamaguchi, Yoshitaka
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- Photo-induced Decarboxylative Heck-Type Coupling of Unactivated Aliphatic Acids and Terminal Alkenes in the Absence of Sacrificial Hydrogen Acceptors
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1,2-Disubstituted alkenes such as vinyl arenes, vinyl silanes, and vinyl boronates are among the most versatile building blocks that can be found in every sector of chemical science. We herein report a noble-metal-free method of accessing such olefins through a photo-induced decarboxylative Heck-type coupling using alkyl carboxylic acids, one of the most ubiquitous building blocks, as the feedstocks. This transformation was achieved in the absence of external oxidants through the synergistic combination of an organo photo-redox catalyst and a cobaloxime catalyst, with H2 and CO2 as the only byproducts. Both control experiments and DFT calculations supported a radical-based mechanism, which eventually led to the development of a selective three-component coupling of aliphatic carboxylic acids, acrylates, and vinyl arenes. More than 90 olefins across a wide range of functionalities were effectively synthesized with this simple protocol.
- Cao, Hui,Jiang, Heming,Feng, Hongyu,Kwan, Jeric Mun Chung,Liu, Xiaogang,Wu, Jie
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supporting information
p. 16360 - 16367
(2018/11/27)
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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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supporting information
p. 916 - 920
(2018/09/22)
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- S,O-ligand-promoted palladium-catalyzed C–H olefination of arenes with allylic substrates
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An efficient catalytic system for the C–H olefination of arenes with different allylic substrates is reported. The catalytic system is based on Pd(OAc)2 and a readily accessible bidentate S,O-ligand. The methodology shows high activity with a wide range of arenes, including bulky and, electron-rich and -poor arenes. The applicability of this catalyst is demonstrated in the late-stage functionalization of the complex molecule O-methylestrone.
- Naksomboon, Kananat,álvarez-Casao, Yolanda,Uiterweerd, Michiel,Westerveld, Nick,Maciá, Beatriz,Fernández-Ibá?ez, M. ángeles
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supporting information
p. 379 - 382
(2017/12/28)
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- Allyl-aryl coupling of allylic carbonates with arylboronic acids catalyzed by palladium nanoparticles in ionic liquid
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A practical and greener process for the allyl-aryl coupling of allylic carbonates with arylboronic acids catalyzed by in situ generated palladium nanoparticles (PdNPs) in ionic liquid (IL) has been described. The PdNPs showed high catalytic activity for the coupling reaction in the IL to afford allyl-aryl coupling products in good to high yields with complete regio- and E/Z selectivities. The PdNPs were readily immobilized in the IL phase and the catalyst can be reused several times without significant loss of catalytic activity and stereospecificity.
- Xu, Jing,Zhai, Xing,Wu, Xue,Zhang, Yong Jian
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supporting information
p. 1712 - 1717
(2015/03/30)
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- A simple and direct method for the palladium-catalyzed oxidative coupling of unactivated allylarenes with classic arenes
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An efficient route to engineer vinylarene structures by the Pd II-catalyzed oxidative coupling of unactivated allylarenes with classic arenes was developed. The methodology features the use of unactivated allylarenes with no prefunctionalization and classic arenes without installed directing groups. A variety of vinylarenes and their saturated derivatives were obtained. They make a great couple: An efficient route to engineer vinylarene structures by PdII-catalyzed oxidative coupling of unactivated allylarenes with classic arenes is developed. The methodology features the use of unactivated allylarenes with no prefunctionalization and classic arenes without installed directing groups. A variety of vinylarenes and their saturated derivatives are obtained.
- Jin, Weiwei,Wong, Wing-Tak,Law, Ga-Lai
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p. 1599 - 1603
(2014/06/24)
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- Rhodium-catalyzed allylic substitution reactions with indium(III) organometallics
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A novel rhodium-catalyzed allylic substitution reaction using indium organometallics is reported. Aryl- and heteroarylindium reagents reacted in THF at 80 °C with primary and secondary allyl halides and their derivatives under rhodium(I) catalysis to afford the α-substituted products in good yields and with high regio- and stereoselectivity. The reaction takes place with substoichiometric amounts of the triorganoindium reagents, which demonstrates the efficiency of the indium-rhodium transmetallation process in carbon-carbon bond-forming reactions. Copyright
- Riveiros, Ricardo,Tato, Ruben,Perez Sestelo, Jose,Sarandeses, Luis A.
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experimental part
p. 3018 - 3023
(2012/07/03)
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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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- Synthesis of 1,3-diarylpropenes through palladium-catalyzed mizoroki-heck and allyl cross-coupling reactions using hydrazones as ligands
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The palladium-catalyzed synthesis of unsymmetrical 1,3-diarylpropenes from allyl esters through a Mizoroki-Heck-type reaction with aryl iodides followed by allyl cross-coupling with a variety of arylboronic acids was developed; the products are obtained in moderate to good yields by using a hydrazone-Pd(OAc) 2 system. The synthesis of unsymmetrical 1,3-diarylpropenes from allyl esters by a Mizoroki-Heck-type reaction followed by allyl cross-coupling with a variety of arylboronic acids was developed; the products were obtained in moderate to good yields by using a hydrazone-Pd(OAc)2 system. Copyright
- Mino, Takashi,Koizumi, Tomoko,Suzuki, Saori,Hirai, Kiminori,Kajiwara, Kenji,Sakamoto, Masami,Fujita, Tsutomu
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supporting information; experimental part
p. 678 - 680
(2012/03/10)
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- A novel, air-stable phosphine ligand for the palladium-catalyzed suzuki-miyaura cross-coupling reaction of chloro arenes
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(Figure presented) A novel, air-stable phosphine ligand, prepared from readily available 2-bromonitrobenzene and vinylmagnesium bromide, combines with Pd(CH3CN)2Cl2 to afford an effective catalyst for Suzuki-Miyaura cross-coupling of aryl, heteroaryl, and allyl chlorides with phenylboronic acid.
- Ghosh, Raju,Adarsh,Sarkar, Amitabha
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experimental part
p. 5320 - 5322
(2010/10/19)
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- Palladium-catalyzed cross-coupling reactions of potassium alkenyltrifluoroborates with organic halides in aqueous media
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Potassium vinyl and alkenyltrifluoroborates are cross-coupled with aryl and heteroaryl bromides using 1 mol % Pd loading of 4-hydroxyacetophenone oxime derived palladacycle or Pd(OAc)2 as precatalysts, K 2CO3 as base, and TBAB as additive and water reflux under conventional or microwave heating to afford styrenes, stilbenoids, and alkenylbenzenes. These borates can be cross-coupled diastereoselectively with allyl and benzyl chlorides using KOH as base in acetone-water (3:2) at 50°C and 0.1 mol % Pd loading, giving the corresponding 1,4-dienes and allylarenes, respectively. These simple phosphine-free reaction conditions allow the palladium recycling from the aqueous phase during up to five runs by extractive separation of the products, which contain 58-105 ppm of Pd.
- Alacid, Emilio,Najera, Carmen
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supporting information; experimental part
p. 2321 - 2327
(2009/07/18)
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- Allylic Ethers as educts for Suzuki-Miyaura couplings in water at room temperature
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(Chemical Equation Presented) The first examples of Suzuki-Miyaura couplings of allylic ethers are reported. These can be done not only under very mild room-temperature conditions but also in water as the only medium. The process is made possible by micel
- Nishikata, Takashi,Lipshutz, Bruce H.
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supporting information; experimental part
p. 12103 - 12105
(2009/12/31)
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- Room-temperature palladium-catalyzed allyl cross-coupling reaction with boronic acids using phosphine-free hydrazone ligands
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Palladium-catalyzed allyl cross-coupling reaction of allylic acetates with a variety of boronic acids at room temperature using a catalytic amount of Pd(OAc)2 with phosphine-free hydrazone as a ligand gave the allylbenzene derivatives in good yields.
- Mino, Takashi,Kajiwara, Kenji,Shirae, Yoshiaki,Sakamoto, Masami,Fujita, Tsutomu
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experimental part
p. 2711 - 2715
(2009/04/11)
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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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- Oxygen-promoted Pd(II) catalysis for the coupling of organoboron compounds and olefins
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(Matrix presented) Reported herein is a mild and efficient Pd(ll) catalysis, leading to the formation of carbon-carbon bonds between a broad spectrum of organoboron compounds and alkenes. Molecular oxygen was employed to reoxidize the resultant Pd(0) species back to Pd(ll) during catalytic cycles. This oxygen protocol promoted the desired Pd(ll) catalysis, whereas it retarded competing Pd(0) catalytic pathways such as Heck or Suzuki couplings.
- Jung, Young Chun,Mishra, Rajesh Kumar,Yoon, Cheol Hwan,Jung, Kyung Woon
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p. 2231 - 2234
(2007/10/03)
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- Palladium-catalyzed cross-coupling reaction of allyl acetates with pinacol aryl- and vinylboronates
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Pinacol boronates 2 couple efficiently with allyl acetates 1 in the presence of a palladium catalyst prepared in situ from PdCl2 and TFP to give the coupled products 3 in moderate to good yields under mild conditions.
- Ortar, Giorgio
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p. 4311 - 4314
(2007/10/03)
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