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Gunda I Georg - One of the best experts on this subject based on the ideXlab platform.
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Boron–Heck Reaction of Cyclic Enaminones: Regioselective Direct Arylation via Oxidative Palladium(II) Catalysis
2015Co-Authors: Yong Wook Kim, Gunda I GeorgAbstract:An oxidative boron–Heck reaction of cyclic Enaminones with arylboronic acids is reported. This protocol provides a regioselective arylation at the C6 position of cyclic Enaminones. When an N-carbamylated cyclic Enaminone was employed, a switch to a conjugate addition reaction occurred in the presence of acid
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boron heck reaction of cyclic Enaminones regioselective direct arylation via oxidative palladium ii catalysis
Organic Letters, 2014Co-Authors: Yong Wook Kim, Gunda I GeorgAbstract:An oxidative boron–Heck reaction of cyclic Enaminones with arylboronic acids is reported. This protocol provides a regioselective arylation at the C6 position of cyclic Enaminones. When an N-carbamylated cyclic Enaminone was employed, a switch to a conjugate addition reaction occurred in the presence of acid.
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2 3 dihydropyridin 4 1h ones and 3 aminocyclohex 2 enones synthesis functionalization and applications to alkaloid synthesis
Synlett, 2014Co-Authors: Hajime Seki, Gunda I GeorgAbstract:This account summarizes our recent investigations into the chemistry of 2,3-dihydropyridin-4(1H)-ones and 3-aminocyclohex-2-enones (Enaminones). These Enaminones are exceptionally versatile chemical scaffolds that serve as valuable intermediates in the synthesis of indolizidine and quinolizidine alkaloids and other bioactive compounds. Since we reported our first method for constructing Enaminones in 2006, we have developed a number of additional approaches to the synthesis and derivatization of Enaminones and we have explored their applications in natural product synthesis. 1 Background 2 Ynone Cyclization 2.1 Initial Discovery 2.2 Optimization of Reaction Conditions 2.3 Scope and Limitations 2.4 Mechanistic Studies 2.4 Application to Quinolone Synthesis 2.6 N-Butoxycarbonyl β-Lactam Approach 2.7 Synthesis of 3,4-Dihydro-1,2-oxazepin-5(2H)-ones and Their Conversion into Enaminones 3 Ketene Cyclization 3.1 Chiral-Pool Approach 3.2 Three-Component Synthesis 4 C5 Functionalization 4.1 Suzuki Coupling of IodoEnaminones 4.2 Suzuki-Type Direct Cross-Coupling 4.3 Suzuki-Type Direct Cross-Coupling with Arylboronic Acids 4.4 Hiyama-Type Direct Cross-Coupling 4.5 Direct Coupling with Aryl Iodides 4.6 Alkenylation by the Fujiwara–Moritani Reaction 4.7 Alkenylation of Uracils 4.8 Aerobic Alkenylation and its Application to the Synthesis of 1,3,5-Trisubstituted Benzenes 4.9 Lithium Perchlorate-Catalyzed Alkylation 5 Applications to Total Synthesis 5.1 Total Synthesis of (+)-Ipalbidine and (+)-Antofine 5.2 Total Synthesis of (R)- and (S)-Boehmeriasin A 5.3 Total Synthesis of Tylocrebrine and Related Phenanthropiperidines 6 Summary and Outlook
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palladium ii catalyzed dehydrogenative alkenylation of cyclic Enaminones via the fujiwara moritani reaction
Organic Letters, 2011Co-Authors: Micah J Niphakis, Gunda I GeorgAbstract:A new Pd(II)-catalyzed dehydrogenative alkenylation reaction involving two alkenes was developed. A variety of nonaromatic, cyclic Enaminones were successfully coupled to primary and secondary alkenes yielding a series of unique 1,3-dienes. The generality of this transformation presents a useful strategy for directly cross-coupling alkenes and offers an attractive new approach to functionalize Enaminones.
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three component synthesis of cyclic Enaminones via ketene cyclization
ChemInform, 2011Co-Authors: Hajime Seki, Gunda I GeorgAbstract:Aza-Michael addition, Wolff rearrangement and a nucleophilic ketene cyclization lead to highly functionalized six-membered Enaminone subunits in a one-pot reaction.
Viktor O Iaroshenko - One of the best experts on this subject based on the ideXlab platform.
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2 3 unsubstituted chromones and their Enaminone precursors as versatile reagents for the synthesis of fused pyridines
Organic and Biomolecular Chemistry, 2012Co-Authors: Viktor O Iaroshenko, Satenik Mkrtchyan, Ashot Gevorgyan, Mariia Miliutina, Alexander Villinger, Dmytro Volochnyuk, Vyacheslav Ya Sosnovskikh, Peter LangerAbstract:A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their Enaminone precursors.
Peter Langer - One of the best experts on this subject based on the ideXlab platform.
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2 3 unsubstituted chromones and their Enaminone precursors as versatile reagents for the synthesis of fused pyridines
Organic and Biomolecular Chemistry, 2012Co-Authors: Viktor O Iaroshenko, Satenik Mkrtchyan, Ashot Gevorgyan, Mariia Miliutina, Alexander Villinger, Dmytro Volochnyuk, Vyacheslav Ya Sosnovskikh, Peter LangerAbstract:A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their Enaminone precursors.
Ashot Gevorgyan - One of the best experts on this subject based on the ideXlab platform.
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2 3 unsubstituted chromones and their Enaminone precursors as versatile reagents for the synthesis of fused pyridines
Organic and Biomolecular Chemistry, 2012Co-Authors: Viktor O Iaroshenko, Satenik Mkrtchyan, Ashot Gevorgyan, Mariia Miliutina, Alexander Villinger, Dmytro Volochnyuk, Vyacheslav Ya Sosnovskikh, Peter LangerAbstract:A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their Enaminone precursors.
Jie-ping Wan - One of the best experts on this subject based on the ideXlab platform.
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Domino C‑H Sulfonylation and Pyrazole Annulation for Fully Substituted Pyrazole Synthesis in Water Using Hydrophilic Enaminones
2019Co-Authors: Yanhui Guo, Li Wei, Guodong Wang, Jie-ping WanAbstract:The cascade reactions between NH2-functionalized Enaminones and sulfonyl hydrazines have been developed for the synthesis of fully substituted pyrazoles. By making use of the hydrophilic primary amino group in the Enaminones, the reactions proceed well in the medium of pure water in the presence of molecular iodine, TBHP, and NaHCO3 via cascade C-H sulfonylation and pyrazole annulation. The cleavage of the C–N bond in Enaminones is confirmed by the experiment using 15N-labeled Enaminone
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Thermoinduced Free-Radical C–H Acyloxylation of Tertiary Enaminones: Catalyst-Free Synthesis of Acyloxyl Chromones and Enaminones
2018Co-Authors: Yanhui Guo, Li Wei, Yunfeng Xiang, Jie-ping WanAbstract:In this paper, the direct acyloxylation of the α-C(sp2)–H bond in tertiary β-Enaminones is accomplished under catalyst-free conditions and ambient temperature by using aroyl peroxides as coupling partners. By means of a thermoinduced free-radical pathway, the present method enables facile and efficient synthesis of both acyloxylated chromones and Enaminones
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synthesis of Enaminones containing diverse n n disubstitution via simple transamination a study with sustainable catalyst free operation
Research on Chemical Intermediates, 2017Co-Authors: Yong Gao, Li Wei, Yunyun Liu, Jie-ping WanAbstract:A systematic investigation on the synthesis of β-Enaminones containing diverse N,N-disubstitution via the transamination of N,N-dimethyl amino functionalized β-Enaminones and secondary amines has been conducted by employing biomass available green solvent ethyl lactate as reaction medium. A class of β-Enaminones containing different N,N-disubstitutions have been smoothly synthesized under the sustainable conditions without using any catalyst.
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Tunable Synthesis of Disulfide-Functionalized Enaminones and 1,4-Thiazines via the Reactions of Enaminones and β‑Aminoethanethiol
2017Co-Authors: Yong Gao, Chengping Wen, Jie-ping WanAbstract:The reactions of β-aminoethanethiol with N,N-dimethyl Enaminones are performed to selectively provide disulfide-functionalized Enaminones and 1,4-thiazines. By performing the reaction in water and catalyst-free conditions, the transamination and oxidative S–S coupling between the two substrates take place to give disulfide-functionalized Enaminones. On the other hand, by using identical starting materials, the employment of the CuI catalyst in dimethyl sulfoxide enables the selective generation of 1,4-thiazines via tandem transamination and C(sp2)–H bond thiolation
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metal free oxidative carbonylation on Enaminone cc bond for the cascade synthesis of benzothiazole containing vicinal diketones
Green Chemistry, 2016Co-Authors: Jie-ping Wan, Yunyun Liu, Youyi Zhou, Shouri ShengAbstract:The cascade reactions between Enaminones and o-aminothiophenols have been implemented to provide unprecedented vicinal diketones containing benzothiazole structures. The construction of the products has been realized under metal-free conditions via carbonylation on the CC double bond of the Enaminone. The tunable synthesis of 2-aroylbenzothiazoles has been achieved by using identical starting materials under modified reaction conditions.