The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
John A. Murphy - One of the best experts on this subject based on the ideXlab platform.
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Tandem radical cyclizations with iodoaryl azides: formal total synthesis of (+/-)-Aspidospermidine.
Organic letters, 2000Co-Authors: Balaram Patro, John A. MurphyAbstract:An iodoazide radical cascade cyclization strategy has been used as the key step in a formal synthesis of Aspidospermidine. Specifically, this step generated the alkaloid's B- and E-rings in the eth...
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tandem radical cyclizations with iodoaryl azides formal total synthesis of Aspidospermidine
Organic Letters, 2000Co-Authors: Balaram Patro, John A. MurphyAbstract:An iodoazide radical cascade cyclization strategy has been used as the key step in a formal synthesis of Aspidospermidine. Specifically, this step generated the alkaloid's B- and E-rings in the eth...
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A novel route to (+/-)-Aspidospermidine: first application of 'radical-polar crossover' reactions to total synthesis
Tetrahedron Letters, 1999Co-Authors: Owen Callaghan, Christopher Lampard, Alan R. Kennedy, John A. MurphyAbstract:Aspidospermidine has been prepared by a novel route featuring TTF-induced cyclisation of a diazonium salt.
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a novel route to Aspidospermidine first application of radical polar crossover reactions to total synthesis
Tetrahedron Letters, 1999Co-Authors: Owen Callaghan, Christopher Lampard, Alan R. Kennedy, John A. MurphyAbstract:Aspidospermidine has been prepared by a novel route featuring TTF-induced cyclisation of a diazonium salt.
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A NOVEL TOTAL SYNTHESIS OF ()-Aspidospermidine
Journal of the Chemical Society Perkin Transactions 1, 1999Co-Authors: Owen Callaghan, Christopher Lampard, Alan R. Kennedy, John A. MurphyAbstract:The tetrathiafulvalene-induced ‘radical–polar crossover’ reaction has been applied to the total synthesis of the pentacyclic Aspidosperma alkaloid Aspidospermidine.
Jieping Zhu - One of the best experts on this subject based on the ideXlab platform.
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aqueous titanium trichloride promoted reductive cyclization of o nitrostyrenes to indoles development and application to the synthesis of rizatriptan and Aspidospermidine
Angewandte Chemie, 2015Co-Authors: Shuo Tong, Qian Wang, Mathias Mamboury, Jieping ZhuAbstract:Treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp(2) )-H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β-disubstituted o-nitrostyrenes, 2,3-disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of Aspidospermidine.
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Aqueous Titanium Trichloride Promoted Reductive Cyclization of o‐Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine
Angewandte Chemie (International ed. in English), 2015Co-Authors: Shuo Tong, Qian Wang, Mathias Mamboury, Jieping ZhuAbstract:Treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp(2) )-H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β-disubstituted o-nitrostyrenes, 2,3-disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of Aspidospermidine.
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unified strategy to monoterpene indole alkaloids total syntheses of goniomitine 1 2 dehydroAspidospermidine Aspidospermidine vincadifformine and kopsihainanine a
Journal of the American Chemical Society, 2014Co-Authors: Olivier Wagnieres, Qian Wang, Jieping ZhuAbstract:Total syntheses of (±)-goniomitine, (±)-1,2-dehydroAspidospermidine, (±)-Aspidospermidine, (±)-vincadifformine, and (±)-kopsihainanine A were achieved featuring two common key steps: (1) a palladium-catalyzed decarboxylative vinylation that provides quick access to cyclopentene intermediates containing all of the carbons present in the natural products and (2) an integrated oxidation/reduction/cyclization (iORC) sequence for skeletal reorganization that converts the cyclopentenes to the pentacyclic structures of the natural products. By incorporation of a geometric constraint to iORC substrates, both the chemoselectivity (C7 vs N1 cyclization) and the stereoselectivity (trans- vs cis-fused ring system) of the cyclization process can be controlled.
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Unified strategy to monoterpene indole alkaloids: total syntheses of (±)-goniomitine, (±)-1,2-dehydroAspidospermidine, (±)-Aspidospermidine, (±)-vincadifformine, and (±)-kopsihainanine A.
Journal of the American Chemical Society, 2014Co-Authors: Olivier Wagnieres, Qian Wang, Jieping ZhuAbstract:Total syntheses of (±)-goniomitine, (±)-1,2-dehydroAspidospermidine, (±)-Aspidospermidine, (±)-vincadifformine, and (±)-kopsihainanine A were achieved featuring two common key steps: (1) a palladium-catalyzed decarboxylative vinylation that provides quick access to cyclopentene intermediates containing all of the carbons present in the natural products and (2) an integrated oxidation/reduction/cyclization (iORC) sequence for skeletal reorganization that converts the cyclopentenes to the pentacyclic structures of the natural products. By incorporation of a geometric constraint to iORC substrates, both the chemoselectivity (C7 vs N1 cyclization) and the stereoselectivity (trans- vs cis-fused ring system) of the cyclization process can be controlled.
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Unified Strategy to Monoterpene Indole Alkaloids: Total Syntheses of (±)-Goniomitine, (±)-1,2-DehydroAspidospermidine, (±)-Aspidospermidine, (±)-Vincadifformine, and (±)-Kopsihainanine A
2014Co-Authors: Olivier Wagnières, Qian Wang, Jieping ZhuAbstract:Total syntheses of (±)-goniomitine, (±)-1,2-dehydroAspidospermidine, (±)-Aspidospermidine, (±)-vincadifformine, and (±)-kopsihainanine A were achieved featuring two common key steps: (1) a palladium-catalyzed decarboxylative vinylation that provides quick access to cyclopentene intermediates containing all of the carbons present in the natural products and (2) an integrated oxidation/reduction/cyclization (iORC) sequence for skeletal reorganization that converts the cyclopentenes to the pentacyclic structures of the natural products. By incorporation of a geometric constraint to iORC substrates, both the chemoselectivity (C7 vs N1 cyclization) and the stereoselectivity (trans- vs cis-fused ring system) of the cyclization process can be controlled
Hiyoshizo Kotsuki - One of the best experts on this subject based on the ideXlab platform.
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enantioselective synthesis of quaternary carbon stereogenic centers through the primary amine catalyzed michael addition reaction of α substituted cyclic ketones at high pressure
European Journal of Organic Chemistry, 2015Co-Authors: Ryo Horinouchi, Kouhei Kamei, Riki Watanabe, Nobushige Hieda, Naoki Tatsumi, Keiji Nakano, Yoshiyasu Ichikawa, Hiyoshizo KotsukiAbstract:The enantioselective Michael addition reaction of α-substituted cyclic ketones with acrylates was efficiently promoted by a primary amine chiral catalyst under high-pressure conditions (1.0 GPa) in tetrahydrofuran. This method was highly successful for the construction of an all-carbon-substituted quaternary-carbon stereogenic center at the α-position of cyclic ketones in high enantiomeric excess, and could be conveniently applied to the formal synthesis of (+)-Aspidospermidine.
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Enantioselective Synthesis of Quaternary Carbon Stereogenic Centers through the Primary Amine‐Catalyzed Michael Addition Reaction of α‐Substituted Cyclic Ketones at High Pressure
European Journal of Organic Chemistry, 2015Co-Authors: Ryo Horinouchi, Kouhei Kamei, Riki Watanabe, Nobushige Hieda, Naoki Tatsumi, Keiji Nakano, Yoshiyasu Ichikawa, Hiyoshizo KotsukiAbstract:The enantioselective Michael addition reaction of α-substituted cyclic ketones with acrylates was efficiently promoted by a primary amine chiral catalyst under high-pressure conditions (1.0 GPa) in tetrahydrofuran. This method was highly successful for the construction of an all-carbon-substituted quaternary-carbon stereogenic center at the α-position of cyclic ketones in high enantiomeric excess, and could be conveniently applied to the formal synthesis of (+)-Aspidospermidine.
Xuefeng Jiang - One of the best experts on this subject based on the ideXlab platform.
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Divergent Asymmetric Total Synthesis of (+)-Vincadifformine, (−)-Quebrachamine, (+)-Aspidospermidine, (−)-Aspidospermine, (−)-Pyrifolidine, and Related Natural Products
Organic letters, 2017Co-Authors: Nengzhong Wang, Du Shuo, Xuefeng JiangAbstract:A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (−)-quebrachamine, (+)-Aspidospermidine, (−)-aspidospermine, (−)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C–E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A–B ring.
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divergent asymmetric total synthesis of vincadifformine quebrachamine Aspidospermidine aspidospermine pyrifolidine and related natural products
Organic Letters, 2017Co-Authors: Nengzhong Wang, Xuefeng JiangAbstract:A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (−)-quebrachamine, (+)-Aspidospermidine, (−)-aspidospermine, (−)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C–E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A–B ring.
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Divergent Asymmetric Total Synthesis of (+)-Vincadifformine, (−)-Quebrachamine, (+)-Aspidospermidine, (−)-Aspidospermine, (−)-Pyrifolidine, and Related Natural Products
2017Co-Authors: Nengzhong Wang, Xuefeng JiangAbstract:A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (−)-quebrachamine, (+)-Aspidospermidine, (−)-aspidospermine, (−)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C–E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A–B ring
Mohammad Movassaghi - One of the best experts on this subject based on the ideXlab platform.
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Enantioselective Synthesis of (−)-Vallesine: Late-Stage C17-Oxidation via Complex Indole Boronation
Organic letters, 2018Co-Authors: Alyssa H. Antropow, Nicholas R. Garcia, Kolby L. White, Mohammad MovassaghiAbstract:The first enantioselective total synthesis of (−)-vallesine via a strategy that features a late-stage regioselective C17-oxidation followed by a highly stereoselective transannular cyclization is reported. The versatility of this approach is highlighted by the divergent synthesis of the archetypal alkaloid of this family, (+)-Aspidospermidine, and an A-ring-oxygenated derivative, (+)-deacetylaspidospermine, the precursor to (−)-vallesine, from a common intermediate.
