- Cross aldolization reactions in furane series by means of silyl enol ethers
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The catalytic cross aldol reaction between a silyl enol ether and an aldehyde has been applied to the furane series giving the ketols RCOCH2CHOHR' (R or R' = 2-furyl). Good results (with no resinification or crotonisation) have been obtained using bismuth
- Le Roux,Maraval,Borredon,Gaspard-Iloughmane,Dubac
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Read Online
- Basic Anion-Exchange Resin-Catalyzed Aldol Condensation of Aromatic Ketones with Aldehydes in Continuous Flow
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A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon-carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer's drug.
- Laroche, Benjamin,Saito, Yuki,Ishitani, Haruro,Kobayashi, Shū
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supporting information
p. 961 - 967
(2019/05/02)
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- Vanadyl species-catalyzed complementary β-oxidative carbonylation of styrene derivatives with aldehydes
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A series of oxometallic species and metal acetylacetonates (acac) was examined as catalysts for oxidative carbonylation of styrene with benzaldehyde using t-butylhydroperoxide as the co-oxidant in warm acetonitrile. Among them, VO((acac)2 and vanadyl(iv) chloride were found to be the only catalyst class to achieve cross-coupling processes by judiciously tuning the ligand electronic attributes, leading to β-hydroxylation- and β-peroxidation-carbonylation of styrene, respectively, in a complementary manner. Mechanistic studies indicated that vanadyl-associated acyl radicals generated by t-butoxy radical-assisted, homolytic cleavage of the aldehyde C-H bond were involved in tandem processes with an exclusive syn diastereoselectivity in the case of β-methylstyrene. This journal is
- Yang, Wen-Chieh,Weng, Shiue-Shien,Ramasamy, Anandhan,Rajeshwaren, Gobi,Liao, Yi-Ya,Chen, Chien-Tien
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supporting information
p. 2385 - 2392
(2015/03/04)
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- PAA-supported Hantzsch 1,4-dihydropyridine ester: An efficient catalyst for the hydrogenation of α,β-epoxy ketones
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A new type of water-soluble polymer-supported NADH co-enzyme model-PAA (polyacrylic acid)-supported Hantzsch 1,4-dihydropyridine ester (PAA-HEH) was designed and synthesized. Catalytic amount of the supported reagent was used in the hydrogenation of α,β-epoxy ketones to the corresponding β-hydroxy ketones and showed great catalytic efficiency in the reduction reaction. This PAA-HEH was an optimal potential for recycling use.
- Zhou, Xin-Feng,Wang, Peng-Fei,Geng, Ye,Xu, Hua-Jian
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supporting information
p. 5374 - 5377
(2013/09/12)
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- Biomimetic hydrogenation: A reusable NADH co-enzyme model for hydrogenation of α,β-epoxy ketones and 1,2-diketones
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A biomimetic method has been developed to transform α,β-epoxy ketones or 1,2-diketones into corresponding β-hydroxy ketones or α-hydroxy ketones using a catalytic amount of BNAH or BNA +Br-. The regeneration of BNAH or BNA+Br - is achieved by a mixture of HCOOH/Et3N. A radical mechanism is proposed to explain these observations.
- Huang, Qiang,Wu, Ji-Wei,Xu, Hua-Jian
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supporting information
p. 3877 - 3881
(2013/07/05)
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- Magnetic nano-Fe3O4-supported 1-benzyl-1,4- dihydronicotinamide (BNAH): Synthesis and application in the catalytic reduction of α,β-epoxy ketones
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A novel magnetically recoverable organic hydride compound was successfully constructed by using silica-coated magnetic nanoparticles as a support. An as-prepared magnetic organic hydride compound, BNAH (1-benzyl-1,4- dihydronicotinamide), showed efficient activity in the catalytic reduction of α,β-epoxy ketones. After reaction, the magnetic nanoparticle- supported BNAH can be separated by simple magnetic separation which made the separation of the product easier.
- Xu, Hua-Jian,Wan, Xin,Shen, Yong-Ya,Xu, Song,Feng, Yi-Si
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supporting information; experimental part
p. 1210 - 1213
(2012/04/18)
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- Study on comparison of reducing ability of three organic hydride compounds
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Selective reduction of three kinds of substrates were studied to evaluate the reducing abilities of N,N-dimethyl-benzimidazolidine (DMBI), 2-phenylbenzimidazoline (PBI) and 2-phenylbenzothiazoline (PBT). As hydride donors, these three five-membered heterocyclic compounds performed different reducing abilities depending on the substrates.
- Feng, Yi-Si,Yang, Chun-Yan,Huang, Qiang,Xu, Hua-Jian
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experimental part
p. 5053 - 5059
(2012/07/28)
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- Catalytic hydrogenation of α,β-epoxy ketones to form β-hydroxy ketones mediated by an NADH coenzyme model
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The hydrogenation of α,β-epoxy ketones can be mediated by a catalytic amount of BNAH or BNA+Br- to form corresponding β-hydroxy ketones in high yield. Na2S2O4 is used as the reducing agent to convert
- Xu, Hua-Jian,Liu, You-Cheng,Fu, Yao,Wu, Yun-Dong
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p. 3449 - 3451
(2007/10/03)
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- Clay montmorillonite K10 catalyzed aldol-type reaction of aldehydes with silyl enol ethers in water
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An environmentally friendly method for the cross aldol reaction of silyl enol ethers and ketene silyl acetal with various aldehydes using montmorillonite K10 is described. Cheap and commercially available montmorillonite K10 can be used without the need of an ion exchange process under solvent-free conditions or in water. Hydrate of aldehydes such as glyoxylic acid can be used directly. Thermal treatment of K10 increased the catalytic activity. The catalytic activity was supposed due to the properties of the structure of K10 and its inherent Bronsted acidity.
- Loh, Teck-Peng,Li, Xu-Ran
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p. 10789 - 10802
(2007/10/03)
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- Synthese de derives furaniques fonctionnels par l'intermediaire d'enoxysilanes. Aldolisation croisee et addition de Michael catalysees par les systemes BiCl3-iodure metallique.
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Synthesis of functional furan derivatives via enoxysilane intermediates.Crossed aldolization and Michael addition catalyzed by BiCl3-metal iodide systems.The catalytic Mukaiyama-aldol reaction using bismuth (III) chloride-sodium or zinc iodide as catalyti
- Roux, C. Le,Gaspard-Iloughmane, H.,Dubac, J.
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p. 832 - 842
(2007/10/02)
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