The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Howard Alper - One of the best experts on this subject based on the ideXlab platform.
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recyclable selective palladium catalyzed synthesis of five six or seven membered ring lactones and lactams by cyclocarbonylation in ionic liquids
Advanced Synthesis & Catalysis, 2006Co-Authors: Howard AlperAbstract:The ionic liquids, BMIM PF6 or BMIM NTf2, are used successfully for the palladium-catalyzed cyclocarbonylation of 2-Allylphenols and anilines, 2-vinylphenols, and 2-aminostyrenes. The reaction proceeds cleanly and efficiently to afford high yields of lactones or lactams with good or excellent selectivity for one isomer. The ionic liquid containing the palladium catalyst, and ligand, is recyclable in all cases.
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regioselective palladium ii catalyzed synthesis of five or seven membered ring lactones and five six or seven membered ring lactams by cyclocarbonylation methodology
Journal of the American Chemical Society, 1996Co-Authors: Bassam El Ali, Kazumi Okuro, Giuseppe Vasapollo, Howard AlperAbstract:2-Allylphenols react with carbon monoxide and hydrogen in the presence of catalytic quantities of a cationic palladium(II) complex [(PCy3)2Pd(H)(H2O)]+BF4- or palladium acetate and 1,4-bis(diphenylphosphino)butane, affording five- or seven-membered ring lactones (bicyclic, tricyclic, and pentacyclic) as the principal products, often in excellent yields. Use of 2-aminostyrenes as reactants and catalytic quantities of palladium acetate and tricyclohexylphosphine, affords five-membered ring lactams in high yield and selectivity. Bicyclic and tricyclic heterocycles containing six-membered ring lactams can be synthesized from the reaction of 2-allylanilines with CO/H2 using the catalytic system Pd(OAc)2/PPh3, while use of 1,4-bis(diphenylphosphino)butane instead of PPh3 in the latter process results in the formation of the seven-membered lactams benzazepinones in good yield. The regiochemical control depends on the nature of the palladium catalyst, the relative pressures of the gases, and the solvent.
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Regioselective Palladium(II)-Catalyzed Synthesis of Five- or Seven-Membered Ring Lactones and Five-, Six- or Seven-Membered Ring Lactams by Cyclocarbonylation Methodology
1996Co-Authors: Bassam El Ali, Kazumi Okuro, Giuseppe Vasapollo, Howard AlperAbstract:The reaction of 2-Allylphenols with carbon monoxide and hydrogen in the presence of catalytic quantities of a cationic palladium(II) complex [(PCy3)2Pd(H)(H2O)]+BF4- or palladium acetate and 1,4-bis(diphenylphosphino)butane, gave five- or seven-membered ring lactones (bicyclic, tricyclic, and pentacyclic) as the principal products, often in excellent yields. Use of 2-aminostyrenes as reactants and catalytic quantities of palladium acetate and tricyclohexylphosphine, gave five-membered ring lactams in high yield and selectivity. Bicyclic and tricyclic heterocycles contg. six-membered ring lactams were synthesized from the reaction of 2-allylanilines with CO/H2 using the catalytic system Pd(OAc)2/PPh3, while use of 1,4-bis(diphenylphosphino)butane instead of PPh3 in the latter process results in the formation of the seven-membered lactams benzazepinones in good yield. The regiochem. control depends on the nature of the palladium catalyst, the relative pressures of the gases, and the solvent. For example, the cyclocarbonylation of 2-Allylphenol gave 4,5-dihydro-1-benzoxepin-2(3H)-one (59% yield) and 3-ethyl-2(3H)-benzofuranone (13% yield) and 3,4-dihydro-2H-1-benzopyran-2-one (28% yield)
Mohamed H Habib - One of the best experts on this subject based on the ideXlab platform.
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the biocatalytic synthesis of syringaresinol from 2 6 dimethoxy 4 allylphenol in one pot using a tailored oxidase peroxidase system
ACS Catalysis, 2018Co-Authors: Milos Trajkovic, Mohamed H Habib, Marco W. FraaijeAbstract:Syringaresinol was synthesized in a one-pot conversion containing eugenol oxidase (EUGO) and horseradish peroxidase (HRP) using the relatively cheap 2,6-dimethoxy-4-allylphenol as a substrate. This conversion is fully coupled as the hydrogen peroxide generated from the reaction of EUGO with the substrate is utilized by the HRP to convert the formed sinapyl alcohol into syringaresinol. To improve the performance of EUGO on 2,6-dimethoxy-4-allylphenol, structure-inspired enzyme engineering was performed. This yielded the I427A EUGO mutant that is significantly more efficient with 2,6-dimethoxy-4-allylphenol. The I427A EUGO mutant together with HRP were capable of efficiently producing syringaresinol as a major product. After optimization and upscaling the conversion to a semipreparative scale (1 gr), syringaresinol was obtained in 81% yield.
Marco W. Fraaije - One of the best experts on this subject based on the ideXlab platform.
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the biocatalytic synthesis of syringaresinol from 2 6 dimethoxy 4 allylphenol in one pot using a tailored oxidase peroxidase system
ACS Catalysis, 2018Co-Authors: Milos Trajkovic, Mohamed H Habib, Marco W. FraaijeAbstract:Syringaresinol was synthesized in a one-pot conversion containing eugenol oxidase (EUGO) and horseradish peroxidase (HRP) using the relatively cheap 2,6-dimethoxy-4-allylphenol as a substrate. This conversion is fully coupled as the hydrogen peroxide generated from the reaction of EUGO with the substrate is utilized by the HRP to convert the formed sinapyl alcohol into syringaresinol. To improve the performance of EUGO on 2,6-dimethoxy-4-allylphenol, structure-inspired enzyme engineering was performed. This yielded the I427A EUGO mutant that is significantly more efficient with 2,6-dimethoxy-4-allylphenol. The I427A EUGO mutant together with HRP were capable of efficiently producing syringaresinol as a major product. After optimization and upscaling the conversion to a semipreparative scale (1 gr), syringaresinol was obtained in 81% yield.
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The Biocatalytic Synthesis of Syringaresinol from 2,6-Dimethoxy-4-allylphenol in One-Pot Using a Tailored Oxidase/Peroxidase System
2018Co-Authors: Mohamed Habib, Milos Trajkovic, Marco W. FraaijeAbstract:Syringaresinol was synthesized in a one-pot conversion containing eugenol oxidase (EUGO) and horseradish peroxidase (HRP) using the relatively cheap 2,6-dimethoxy-4-allylphenol as a substrate. This conversion is fully coupled as the hydrogen peroxide generated from the reaction of EUGO with the substrate is utilized by the HRP to convert the formed sinapyl alcohol into syringaresinol. To improve the performance of EUGO on 2,6-dimethoxy-4-allylphenol, structure-inspired enzyme engineering was performed. This yielded the I427A EUGO mutant that is significantly more efficient with 2,6-dimethoxy-4-allylphenol. The I427A EUGO mutant together with HRP were capable of efficiently producing syringaresinol as a major product. After optimization and upscaling the conversion to a semipreparative scale (1 gr), syringaresinol was obtained in 81% yield
Bassam El Ali - One of the best experts on this subject based on the ideXlab platform.
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regioselective palladium ii catalyzed synthesis of five or seven membered ring lactones and five six or seven membered ring lactams by cyclocarbonylation methodology
Journal of the American Chemical Society, 1996Co-Authors: Bassam El Ali, Kazumi Okuro, Giuseppe Vasapollo, Howard AlperAbstract:2-Allylphenols react with carbon monoxide and hydrogen in the presence of catalytic quantities of a cationic palladium(II) complex [(PCy3)2Pd(H)(H2O)]+BF4- or palladium acetate and 1,4-bis(diphenylphosphino)butane, affording five- or seven-membered ring lactones (bicyclic, tricyclic, and pentacyclic) as the principal products, often in excellent yields. Use of 2-aminostyrenes as reactants and catalytic quantities of palladium acetate and tricyclohexylphosphine, affords five-membered ring lactams in high yield and selectivity. Bicyclic and tricyclic heterocycles containing six-membered ring lactams can be synthesized from the reaction of 2-allylanilines with CO/H2 using the catalytic system Pd(OAc)2/PPh3, while use of 1,4-bis(diphenylphosphino)butane instead of PPh3 in the latter process results in the formation of the seven-membered lactams benzazepinones in good yield. The regiochemical control depends on the nature of the palladium catalyst, the relative pressures of the gases, and the solvent.
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Regioselective Palladium(II)-Catalyzed Synthesis of Five- or Seven-Membered Ring Lactones and Five-, Six- or Seven-Membered Ring Lactams by Cyclocarbonylation Methodology
1996Co-Authors: Bassam El Ali, Kazumi Okuro, Giuseppe Vasapollo, Howard AlperAbstract:The reaction of 2-Allylphenols with carbon monoxide and hydrogen in the presence of catalytic quantities of a cationic palladium(II) complex [(PCy3)2Pd(H)(H2O)]+BF4- or palladium acetate and 1,4-bis(diphenylphosphino)butane, gave five- or seven-membered ring lactones (bicyclic, tricyclic, and pentacyclic) as the principal products, often in excellent yields. Use of 2-aminostyrenes as reactants and catalytic quantities of palladium acetate and tricyclohexylphosphine, gave five-membered ring lactams in high yield and selectivity. Bicyclic and tricyclic heterocycles contg. six-membered ring lactams were synthesized from the reaction of 2-allylanilines with CO/H2 using the catalytic system Pd(OAc)2/PPh3, while use of 1,4-bis(diphenylphosphino)butane instead of PPh3 in the latter process results in the formation of the seven-membered lactams benzazepinones in good yield. The regiochem. control depends on the nature of the palladium catalyst, the relative pressures of the gases, and the solvent. For example, the cyclocarbonylation of 2-Allylphenol gave 4,5-dihydro-1-benzoxepin-2(3H)-one (59% yield) and 3-ethyl-2(3H)-benzofuranone (13% yield) and 3,4-dihydro-2H-1-benzopyran-2-one (28% yield)
Christopher J Moody - One of the best experts on this subject based on the ideXlab platform.
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microwave assisted combined mitsunobu reaction claisen rearrangement and microwave assisted phenol oxidation rapid synthesis of 2 6 disubstituted 1 4 benzoquinone natural products
Tetrahedron Letters, 2005Co-Authors: Aouregan M Jacob, Christopher J MoodyAbstract:Abstract Microwave irradiation of a phenol, an allylic alcohol, di-isopropyl azodicarboxylate and triphenylphosphine at 220–240 °C for 30 min results in a combined Mitsunobu reaction and Claisen rearrangement to give the rearranged 2-Allylphenol. Following the first detailed study of microwave-assisted phenol oxidation, rapid syntheses of the natural products primin and 2-methoxy-6-pentadecyl-1,4-benzoquinone (four reaction steps, total reaction time 1 h) were achieved using this combined Mitsunobu–Claisen strategy in combination with two further microwave-assisted steps (alkene hydrogenation and phenol oxidation).
