Remarkable Dendritic Effect in the Polymer-Supported Catalysis of the Heck Arylation of Olefins

Dahan, Adi; Portnoy, Moshe

doi:10.1021/ol0340181

Cited by 106 publications

(44 citation statements)

References 35 publications

(19 reference statements)

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“…Enhanced rates of dihydroxylation of olefin using osmium cored dendrimer were reported recently [20]. In addition to homogeneous dendritic catalysts, positive dendritic effects arising from polymer supported dendritic catalysts were also demonstrated [21,22]. Studies described so-far illustrated effects of catalytic centers, primarily among different generations of dendrimers, with complete functionalization of their peripheries with catalytic moieties.…”

Section: Introductionmentioning

confidence: 97%

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Bagul

Jayaraman

2012

Journal of Organometallic Chemistry

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Section: Introductionmentioning

confidence: 97%

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Bagul

Jayaraman

2012

Journal of Organometallic Chemistry

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“…1 Nevertheless, arylation of electron-rich olefins such as enol ethers is often limited by poor a:b regioselectivity. [2][3][4][5][6] High a-regioselective arylations in the presence of n-butylvinylether have been reported by Cabri et al and Hallberg et al in the presence of Pd(OAc) 2 / dppp. [7][8][9][10] In some procedures, TlOAc was added in order to improve the regioselectivity of the reaction.…”

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confidence: 92%

Direct Synthesis of Protected Arylacetaldehydes by Palladium-Tetraphosphine-Catalyzed Arylation of Ethyleneglycol Vinylether

Kondolff¹,

Doucet²,

Santelli³

2004

Synlett

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Through the use of [PdCl(C 3 H 5 )] 2 /cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl) cyclopentane as a catalyst, a range of aryl bromides undergo Heck reaction with ethyleneglycol vinylether to give regioselectively protected arylacetaldehydes in good yields. The b-arylation products were obtained in the range 93-98% selectivity with electron-poor aryl bromides. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. The arylvinyl ethers intermediates undergo subsequent ketalization to give the corresponding 2-benzyl-1,3-dioxolane derivatives.Palladium-catalyzed functionalization of aromatic halides has become an important method in preparative organic chemistry. 1 Nevertheless, arylation of electron-rich olefins such as enol ethers is often limited by poor a:b regioselectivity. 2-6 High a-regioselective arylations in the presence of n-butylvinylether have been reported by Cabri et al. and Hallberg et al. in the presence of Pd(OAc) 2 / dppp. 7-10 In some procedures, TlOAc was added in order to improve the regioselectivity of the reaction. The reaction performed in ionic liquids as solvent also led selectively to the a-arylation. 11 On the other hand, poly(ethylene glycol) used as solvent with Pd(OAc) 2 as catalyst led selectively to the b-arylated products. 12 It has been demonstrated that the regioselectivity of the addition of organopalladium intermediates can be influenced by coordinating groups adjacent to the substrate double bond. 13-16 For example, Hallberg et al. have described that the nitrogen containing vinyl ethers [2-(dimethylamino)ethoxy]-ethene in the presence of palladium acetate led to regioselective b-arylation of several aryl halides. 13,15 On the other hand, in the presence of ethylene glycol vinylether with Pd(OAc) 2 /dppp as catalyst they obtained selectively the a-arylations to give aryl vinyl ethers, which undergo subsequent ketalization to form selectively the isomer e in Scheme 1. 17 Surprisingly, to our knowledge, the selective b-arylation in the presence of ethylene glycol vinylether has never been described.In order to obtain stable and efficient palladium catalysts, we have prepared the new tetraphosphine ligand, cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane or Tedicyp 18 (Scheme 1) in which four diphenylphosphino groups are stereospecifically bound to the same face of a cyclopentane ring. We have already reported the results obtained in allylic substitution, 18 for Suzuki cross-coupling, 19 and for Sonogashira alkynylation 20 using Tedicyp as the ligand. We have also reported several results obtained for Heck vinylation reaction. 21 We had observed that with n-butylvinyl ether in the presence of the tetraphosphine Tedicyp associated to [Pd(C 3 H 5 )Cl] 2 , high reaction rates but moderate to good regioselectivities in favour of b-arylation could be obtained, 21c but in many cases these selectivities were not high enough to provide a useful process for the preparation of protected arylacetaldehydes...

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“…The immobilization of metal catalysts on solid supports has become a valuable tool for the efficient separation of organic products and catalyst recycling. Polymers play a significant role in this area, offering different ways of metal attachment to the polymer matrix via covalent or non-covalent bonding, through hydrogen bridges, as well as through ionic, hydrophobic or fluorous interactions [37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Use of a recyclable poly(N-vinyl carbazole) palladium(II) complex catalyst: Heck cross-coupling reaction under phosphine-free and aerobic conditions

Islam

Mondal

Roy

et al. 2010

Transition Met Chem

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A novel pathway for cross-coupling reaction of terminal alkenes with aryl halides (Heck cross-coupling) has been described using a new phosphine-free poly(Nvinyl carbazole) anchored palladium(II) complex as catalyst in aerobic conditions. The catalyst was found to be highly active for the couplings of a variety of substituted and non-substituted aryl halides with terminal alkenes and to smoothly afford the corresponding desired products in good to excellent yields. The catalyst can be reused at least six times without noticeable decrease in catalytic activity.

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Remarkable Dendritic Effect in the Polymer-Supported Catalysis of the Heck Arylation of Olefins

Cited by 106 publications

References 35 publications

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Direct Synthesis of Protected Arylacetaldehydes by Palladium-Tetraphosphine-Catalyzed Arylation of Ethyleneglycol Vinylether

Use of a recyclable poly(N-vinyl carbazole) palladium(II) complex catalyst: Heck cross-coupling reaction under phosphine-free and aerobic conditions

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Remarkable Dendritic Effect in the Polymer-Supported Catalysis of the Heck Arylation of Olefins

Cited by 106 publications

References 35 publications

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Efficacies of multivalent vs monovalent poly(ether imine) dendritic catalysts within a generation in multiple C–C bond forming reactions

Direct Synthesis of Protected Arylacetaldehydes by Palladium-Tetra­phosphine-Catalyzed Arylation of Ethyleneglycol Vinylether

Use of a recyclable poly(N-vinyl carbazole) palladium(II) complex catalyst: Heck cross-coupling reaction under phosphine-free and aerobic conditions

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Direct Synthesis of Protected Arylacetaldehydes by Palladium-Tetraphosphine-Catalyzed Arylation of Ethyleneglycol Vinylether