The Experts below are selected from a list of 25299 Experts worldwide ranked by ideXlab platform
Feng Sha - One of the best experts on this subject based on the ideXlab platform.
-
enantioselective direct vinylogous aldol cyclization Cascade Reaction between β γ unsaturated amides and o quinones
Organic and Biomolecular Chemistry, 2016Co-Authors: Yu Jiang, Feng ShaAbstract:1,2-Diketones are employed, for the first time, as electrophiles in the vinylogous aldol Reaction. With 5 mol% of chiral tertiary amine-thiourea C8, a direct vinylogous aldol-cyclization Cascade Reaction between β,γ-unsaturated amides and o-quinones has been achieved to produce spirocyclic dihydropyranones in 76–99% yield and 82–95% ee.
-
direct enantioselective vinylogous aldol cyclization Cascade Reaction of allyl pyrazoleamides with isatins asymmetric construction of spirocyclic oxindole dihydropyranones
Chemical Communications, 2014Co-Authors: Yu Jiang, Yuqing Guan, Feng ShaAbstract:The first enantioselective vinylogous aldol–cyclization Cascade Reaction of allyl pyrazoleamides with isatins is reported. With 1 mol% of Takemoto catalyst, optically active spirocyclic oxindole–dihydropyranones were obtained in excellent yields (93–99%) and good-to-excellent enantioselectivities (82–97% ee).
Christopher A. Alabi - One of the best experts on this subject based on the ideXlab platform.
-
Sequence-defined bioactive macrocycles via an acid-catalysed Cascade Reaction
Nature Chemistry, 2016Co-Authors: Mintu Porel, Dana N. Thornlow, Ngoc N. Phan, Christopher A. AlabiAbstract:Macrocyclic oligomers are a unique structural class of compounds in which the ring size and structure can be tuned through the precise control of the primary sequence. Now, it has been shown that oligothioetheramide (oligoTEA) macrocycles can be synthesized using a one-pot acid-catalysed Cascade Reaction. Preliminary results indicate that cationic oligoTEAs are promising bactericidal agents. Synthetic macrocycles derived from sequence-defined oligomers are a unique structural class whose ring size, sequence and structure can be tuned via precise organization of the primary sequence. Similar to peptides and other peptidomimetics, these well-defined synthetic macromolecules become pharmacologically relevant when bioactive side chains are incorporated into their primary sequence. In this article, we report the synthesis of oligothioetheramide (oligoTEA) macrocycles via a one-pot acid-catalysed Cascade Reaction. The versatility of the cyclization chemistry and modularity of the assembly process was demonstrated via the synthesis of >20 diverse oligoTEA macrocycles. Structural characterization via NMR spectroscopy revealed the presence of conformational isomers, which enabled the determination of local chain dynamics within the macromolecular structure. Finally, we demonstrate the biological activity of oligoTEA macrocycles designed to mimic facially amphiphilic antimicrobial peptides. The preliminary results indicate that macrocyclic oligoTEAs with just two-to-three cationic charge centres can elicit potent antibacterial activity against Gram-positive and Gram-negative bacteria.
-
sequence defined bioactive macrocycles via an acid catalysed Cascade Reaction
Nature Chemistry, 2016Co-Authors: Mintu Porel, Dana N. Thornlow, Ngoc N. Phan, Christopher A. AlabiAbstract:Synthetic macrocycles derived from sequence-defined oligomers are a unique structural class whose ring size, sequence and structure can be tuned via precise organization of the primary sequence. Similar to peptides and other peptidomimetics, these well-defined synthetic macromolecules become pharmacologically relevant when bioactive side chains are incorporated into their primary sequence. In this article, we report the synthesis of oligothioetheramide (oligoTEA) macrocycles via a one-pot acid-catalysed Cascade Reaction. The versatility of the cyclization chemistry and modularity of the assembly process was demonstrated via the synthesis of >20 diverse oligoTEA macrocycles. Structural characterization via NMR spectroscopy revealed the presence of conformational isomers, which enabled the determination of local chain dynamics within the macromolecular structure. Finally, we demonstrate the biological activity of oligoTEA macrocycles designed to mimic facially amphiphilic antimicrobial peptides. The preliminary results indicate that macrocyclic oligoTEAs with just two-to-three cationic charge centres can elicit potent antibacterial activity against Gram-positive and Gram-negative bacteria.
Yu Jiang - One of the best experts on this subject based on the ideXlab platform.
-
enantioselective direct vinylogous aldol cyclization Cascade Reaction between β γ unsaturated amides and o quinones
Organic and Biomolecular Chemistry, 2016Co-Authors: Yu Jiang, Feng ShaAbstract:1,2-Diketones are employed, for the first time, as electrophiles in the vinylogous aldol Reaction. With 5 mol% of chiral tertiary amine-thiourea C8, a direct vinylogous aldol-cyclization Cascade Reaction between β,γ-unsaturated amides and o-quinones has been achieved to produce spirocyclic dihydropyranones in 76–99% yield and 82–95% ee.
-
direct enantioselective vinylogous aldol cyclization Cascade Reaction of allyl pyrazoleamides with isatins asymmetric construction of spirocyclic oxindole dihydropyranones
Chemical Communications, 2014Co-Authors: Yu Jiang, Yuqing Guan, Feng ShaAbstract:The first enantioselective vinylogous aldol–cyclization Cascade Reaction of allyl pyrazoleamides with isatins is reported. With 1 mol% of Takemoto catalyst, optically active spirocyclic oxindole–dihydropyranones were obtained in excellent yields (93–99%) and good-to-excellent enantioselectivities (82–97% ee).
Fumin Zhang - One of the best experts on this subject based on the ideXlab platform.
-
efficient oxa diels alder semipinacol rearrangement aldol Cascade Reaction short approach to polycyclic architectures
ChemInform, 2015Co-Authors: Jinbao Peng, Yue Qi, Zeran Jing, Shaohua Wang, Yongqiang Tu, Fumin ZhangAbstract:A novel carbon electrophile induced intermolecular oxa-Diels—Alder/semipinacol rearrangement/aldol Cascade Reaction of allylic silyl ether with β,γ-unsaturated α-ketoester is developed under the promotion of SnCl4.
-
efficient oxa diels alder semipinacol rearrangement aldol Cascade Reaction short approach to polycyclic architectures
Organic Letters, 2015Co-Authors: Jinbao Peng, Yue Qi, Zeran Jing, Shaohua Wang, Yongqiang Tu, Fumin ZhangAbstract:A novel carbon electrophile induced intermolecular oxa-Diels–Alder/semipinacol rearrangement/aldol Cascade Reaction of allylic silyl ether with β,γ-unsaturated α-ketoester has been developed under the promotion of SnCl4. This highly efficient transformation enables the quick construction of polycyclic architectures with up to five contiguous stereogenic centers in a single operation with moderate to good yields as well as high diastereoselectivity and would provide versatile short approaches to frameworks and/or analogues of numerous biologically important polycyclic natural products.
Mintu Porel - One of the best experts on this subject based on the ideXlab platform.
-
Sequence-defined bioactive macrocycles via an acid-catalysed Cascade Reaction
Nature Chemistry, 2016Co-Authors: Mintu Porel, Dana N. Thornlow, Ngoc N. Phan, Christopher A. AlabiAbstract:Macrocyclic oligomers are a unique structural class of compounds in which the ring size and structure can be tuned through the precise control of the primary sequence. Now, it has been shown that oligothioetheramide (oligoTEA) macrocycles can be synthesized using a one-pot acid-catalysed Cascade Reaction. Preliminary results indicate that cationic oligoTEAs are promising bactericidal agents. Synthetic macrocycles derived from sequence-defined oligomers are a unique structural class whose ring size, sequence and structure can be tuned via precise organization of the primary sequence. Similar to peptides and other peptidomimetics, these well-defined synthetic macromolecules become pharmacologically relevant when bioactive side chains are incorporated into their primary sequence. In this article, we report the synthesis of oligothioetheramide (oligoTEA) macrocycles via a one-pot acid-catalysed Cascade Reaction. The versatility of the cyclization chemistry and modularity of the assembly process was demonstrated via the synthesis of >20 diverse oligoTEA macrocycles. Structural characterization via NMR spectroscopy revealed the presence of conformational isomers, which enabled the determination of local chain dynamics within the macromolecular structure. Finally, we demonstrate the biological activity of oligoTEA macrocycles designed to mimic facially amphiphilic antimicrobial peptides. The preliminary results indicate that macrocyclic oligoTEAs with just two-to-three cationic charge centres can elicit potent antibacterial activity against Gram-positive and Gram-negative bacteria.
-
sequence defined bioactive macrocycles via an acid catalysed Cascade Reaction
Nature Chemistry, 2016Co-Authors: Mintu Porel, Dana N. Thornlow, Ngoc N. Phan, Christopher A. AlabiAbstract:Synthetic macrocycles derived from sequence-defined oligomers are a unique structural class whose ring size, sequence and structure can be tuned via precise organization of the primary sequence. Similar to peptides and other peptidomimetics, these well-defined synthetic macromolecules become pharmacologically relevant when bioactive side chains are incorporated into their primary sequence. In this article, we report the synthesis of oligothioetheramide (oligoTEA) macrocycles via a one-pot acid-catalysed Cascade Reaction. The versatility of the cyclization chemistry and modularity of the assembly process was demonstrated via the synthesis of >20 diverse oligoTEA macrocycles. Structural characterization via NMR spectroscopy revealed the presence of conformational isomers, which enabled the determination of local chain dynamics within the macromolecular structure. Finally, we demonstrate the biological activity of oligoTEA macrocycles designed to mimic facially amphiphilic antimicrobial peptides. The preliminary results indicate that macrocyclic oligoTEAs with just two-to-three cationic charge centres can elicit potent antibacterial activity against Gram-positive and Gram-negative bacteria.
