The Experts below are selected from a list of 204543 Experts worldwide ranked by ideXlab platform
Carles J Bayon - One of the best experts on this subject based on the ideXlab platform.
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hydroformylation of myrcene metal and Ligand effects in the hydroformylation of conjugated dienes
New Journal of Chemistry, 2003Co-Authors: Claudia M Foca, Humberto J V Barros, Eduardo Dos N Santos, Elena V Gusevskaya, Carles J BayonAbstract:The hydroformylation of myrcene catalyzed by Rh and Pt/Sn catalysts containing different P-Donor Ligands leads to the formation of a number of mono- and dialdehydes. Nine major products of the reaction have been characterized, showing that they arise from the n-alkyl and η3-allyl intermediates, formed through the reaction of the metal catalysts with the less substituted CC bond of the substrate. Thus, 4-methylene-8-methyl-7-nonenal is the major aldehyde formed with Pt/Sn catalysts, regardless of the P-Donor Ligand used. This aldehyde is also the main product of the reaction catalyzed by the Rh/xantphos system (xantphos = 9,9-dimethyl-4,6-bis(diphenylphosphino)xantene). However, with Ligands such as bisbi (bisbi = 2,2′-bis((diphenylphosphino)methyl)-1,1′-biphenyl), also with bite angles around 120°, but with more flexible backbones than xantphos, rhodium catalysts yield mainly cis- and trans-3-ethylidene-7-methyl-6-octenal. These two aldehydes are also formed in the reactions catalyzed by Rh and P-Donor monodentate Ligands or the bidentante ones with bite angles around 90° (dppe, dppp). For the last type of Ligands, an increase in the flexibility of the backbone reduces the selectivity for the β,γ-unsaturated aldehydes.
Claudia M Foca - One of the best experts on this subject based on the ideXlab platform.
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hydroformylation of myrcene metal and Ligand effects in the hydroformylation of conjugated dienes
New Journal of Chemistry, 2003Co-Authors: Claudia M Foca, Humberto J V Barros, Eduardo Dos N Santos, Elena V Gusevskaya, Carles J BayonAbstract:The hydroformylation of myrcene catalyzed by Rh and Pt/Sn catalysts containing different P-Donor Ligands leads to the formation of a number of mono- and dialdehydes. Nine major products of the reaction have been characterized, showing that they arise from the n-alkyl and η3-allyl intermediates, formed through the reaction of the metal catalysts with the less substituted CC bond of the substrate. Thus, 4-methylene-8-methyl-7-nonenal is the major aldehyde formed with Pt/Sn catalysts, regardless of the P-Donor Ligand used. This aldehyde is also the main product of the reaction catalyzed by the Rh/xantphos system (xantphos = 9,9-dimethyl-4,6-bis(diphenylphosphino)xantene). However, with Ligands such as bisbi (bisbi = 2,2′-bis((diphenylphosphino)methyl)-1,1′-biphenyl), also with bite angles around 120°, but with more flexible backbones than xantphos, rhodium catalysts yield mainly cis- and trans-3-ethylidene-7-methyl-6-octenal. These two aldehydes are also formed in the reactions catalyzed by Rh and P-Donor monodentate Ligands or the bidentante ones with bite angles around 90° (dppe, dppp). For the last type of Ligands, an increase in the flexibility of the backbone reduces the selectivity for the β,γ-unsaturated aldehydes.
Saravanabharathi D - One of the best experts on this subject based on the ideXlab platform.
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Rhodium(I) complexes of \alpha-keto-stabilised 1,2-bis(diphenylphosphino)alkane mono ylides
Indian Academy of Sciences, 2003Co-Authors: Saravanabharathi D, Ts Venkatakrishnan, Nethaji M, Ss KrishnamurthyAbstract:Rhodium(I) complexes of the hybrid ylide-phosphine Ligands, $Ph_2P(CH_2)_nPPh_2(CHC(O)C_6H_5)$ (n = 1: dppm-yl, or 2: dppe-yl) have been synthesized from $[Rh(\mu-Cl)(COD)]_2$ (COD = 1,5-cyclooctadiene) and characterized by NMR spectroscopic and X-ray structural methods. The dppe-yl behaves as an ambidentate Ligand; it functions as a monodentate P-Donor Ligand with a dangling ylidic carbon in the neutral chloro complex, [(COD)Rh(Cl)(dppe-yl)] (1), whereas replacement of the chloride by a non-coordinating counter anion results in the formation of the complexes, $[(COD)Rh(L-L')]^+$ (L-L' = dppe-yl (2) or dppm-yl (3)) respectively in which the Ligands are bonded to the metal via the phosphorus and the ylidic carbon atoms. The 1,5- cyclooctadiene (COD), present in the Rh(I) precursor, remains intact in the products. The structures of 1, 2 and 3 have been confirmed by X-ray crystallography
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Rhodium(I) complexes of α-keto-stabilised 1,2-bis(diphenylphosphino)alkane mono ylides
Indian Academy of Sciences, 2003Co-Authors: Saravanabharathi D, Nethaji M, Venkatakrishnan T. S., Krishnamurthy, Setharampattu S.Abstract:Rhodium(I) complexes of the hybrid ylide-phosphine Ligands, Ph2P(CH2) n PPh2(CHC(O)C6H5) (n = 1: dppm-yl, or 2: dppe-yl) have been synthesised from [Rh(μ-C1)(COD)]2 (COD = 1,5-cyclooctadiene) and characterized by NMR spectroscopic and X-ray structural methods. The dppe-yl behaves as an ambidentate Ligand; it functions as a monodentate P-Donor Ligand with a dangling ylidic carbon in the neutral chloro complex, [(COD)Rh(Cl)(dppe-yl)] (1), whereas replacement of the chloride by a non-coordinating counter anion results in the formation of the complexes, [(COD)Rh(L-L')]+ (L-L' = dppe-yl (2) or dppm-yl (3)) respectively in which the Ligands are bonded to the metal via the phosphorus and the ylidic carbon atoms. The 1,5-cyclooctadiene (COD), present in the Rh(I) precursor, remains intact in the products. The structures of 1,2 and3 have been confirmed by X-ray crystallography
Eduardo Dos N Santos - One of the best experts on this subject based on the ideXlab platform.
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hydroformylation of myrcene metal and Ligand effects in the hydroformylation of conjugated dienes
New Journal of Chemistry, 2003Co-Authors: Claudia M Foca, Humberto J V Barros, Eduardo Dos N Santos, Elena V Gusevskaya, Carles J BayonAbstract:The hydroformylation of myrcene catalyzed by Rh and Pt/Sn catalysts containing different P-Donor Ligands leads to the formation of a number of mono- and dialdehydes. Nine major products of the reaction have been characterized, showing that they arise from the n-alkyl and η3-allyl intermediates, formed through the reaction of the metal catalysts with the less substituted CC bond of the substrate. Thus, 4-methylene-8-methyl-7-nonenal is the major aldehyde formed with Pt/Sn catalysts, regardless of the P-Donor Ligand used. This aldehyde is also the main product of the reaction catalyzed by the Rh/xantphos system (xantphos = 9,9-dimethyl-4,6-bis(diphenylphosphino)xantene). However, with Ligands such as bisbi (bisbi = 2,2′-bis((diphenylphosphino)methyl)-1,1′-biphenyl), also with bite angles around 120°, but with more flexible backbones than xantphos, rhodium catalysts yield mainly cis- and trans-3-ethylidene-7-methyl-6-octenal. These two aldehydes are also formed in the reactions catalyzed by Rh and P-Donor monodentate Ligands or the bidentante ones with bite angles around 90° (dppe, dppp). For the last type of Ligands, an increase in the flexibility of the backbone reduces the selectivity for the β,γ-unsaturated aldehydes.
Humberto J V Barros - One of the best experts on this subject based on the ideXlab platform.
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hydroformylation of myrcene metal and Ligand effects in the hydroformylation of conjugated dienes
New Journal of Chemistry, 2003Co-Authors: Claudia M Foca, Humberto J V Barros, Eduardo Dos N Santos, Elena V Gusevskaya, Carles J BayonAbstract:The hydroformylation of myrcene catalyzed by Rh and Pt/Sn catalysts containing different P-Donor Ligands leads to the formation of a number of mono- and dialdehydes. Nine major products of the reaction have been characterized, showing that they arise from the n-alkyl and η3-allyl intermediates, formed through the reaction of the metal catalysts with the less substituted CC bond of the substrate. Thus, 4-methylene-8-methyl-7-nonenal is the major aldehyde formed with Pt/Sn catalysts, regardless of the P-Donor Ligand used. This aldehyde is also the main product of the reaction catalyzed by the Rh/xantphos system (xantphos = 9,9-dimethyl-4,6-bis(diphenylphosphino)xantene). However, with Ligands such as bisbi (bisbi = 2,2′-bis((diphenylphosphino)methyl)-1,1′-biphenyl), also with bite angles around 120°, but with more flexible backbones than xantphos, rhodium catalysts yield mainly cis- and trans-3-ethylidene-7-methyl-6-octenal. These two aldehydes are also formed in the reactions catalyzed by Rh and P-Donor monodentate Ligands or the bidentante ones with bite angles around 90° (dppe, dppp). For the last type of Ligands, an increase in the flexibility of the backbone reduces the selectivity for the β,γ-unsaturated aldehydes.
