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Min Shi - One of the best experts on this subject based on the ideXlab platform.
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rhodium ii catalyzed intermolecular 3 2 annulation of n vinyl indoles with n Tosyl 1 2 3 triazoles via an aza vinyl rh carbene
Organic chemistry frontiers, 2017Co-Authors: Bo Jiang, Min ShiAbstract:The rhodium(II)-catalyzed annulations of N-vinyl indole derivatives and N-Tosyl-1,2,3-triazoles have been developed in this paper, providing a convenient, efficient and straightforward access to synthesize indoles containing a N-dihydropyrrole in moderate to good yields. Furthermore, the reaction of N-vinyl indoles with 2.5 equiv. of N-Tosyl-1,2,3-triazoles gave C3-functionalized indoles containing a N-dihydropyrrole in moderate yields after reduction with NaBH3CN in a one-pot manner. This finding gives a new synthetic protocol for the preparation of indoles containing a N-dihydropyrrole under mild conditions.
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asymmetric catalytic aza morita baylis hillman reaction aza mbh an interesting functional group caused reversal of asymmetric induction
Chemical Communications, 2008Co-Authors: Min Shi, Xuguang LiuAbstract:A highly efficient aza-Morita–Baylis–Hillman reaction (aza-MBH reaction) of N-Tosyl salicylaldehyde imines with α,β-unsaturated ketones has been achieved by using β-isocupreidine (β-ICPD) as the catalyst (10 mol%) to give the corresponding adducts in good to high yields (90%–quant.) and excellent ee’s (up to 99% ee), with adducts showing the opposite absolute configuration to that of those obtained in the similar aza-MBH reaction of N-Tosyl aldimines with α,β-unsaturated ketones.
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baylis hillman reactions of n Tosyl aldimines and aryl aldehydes with 3 methylpenta 3 4 dien 2 one
Organic and Biomolecular Chemistry, 2005Co-Authors: Guiling Zhao, Min ShiAbstract:The attempted Baylis–Hillman reactions of N-Tosyl aldimines and aryl aldehydes with 3-methylpenta-3,4-dien-2-one gave the corresponding Baylis–Hillman adducts 3 and 6 in moderate to good yields in the presence of DMAP in DMSO, respectively. In the case of the aza-Baylis–Hillman reactions of N-Tosyl aldimines with 3-methylpenta-3,4-dien-2-one catalyzed by PBu3, the corresponding aza-Baylis–Hillman derivatives 4 and 5 were formed at the same time.
Yunyun Liu - One of the best experts on this subject based on the ideXlab platform.
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base promoted synthesis of n substituted 1 2 3 triazoles via enaminone azide cycloaddition involving regitz diazo transfer
Organic Letters, 2016Co-Authors: Jieping Wan, Shuo Cao, Yunyun LiuAbstract:The domino reactions between NH-based secondary enaminones and Tosyl azide have been developed for the synthesis of various N-substituted 1,2,3-triazoles by employing t-BuONa as the base promoter. Through a key Regitz diazo-transfer process with Tosyl azide, the reactions proceed efficiently at room temperature with good substrate tolerance.
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Base-Promoted Synthesis of N‑Substituted 1,2,3-Triazoles via Enaminone–Azide Cycloaddition Involving Regitz Diazo Transfer
2016Co-Authors: Jieping Wan, Shuo Cao, Yunyun LiuAbstract:The domino reactions between NH-based secondary enaminones and Tosyl azide have been developed for the synthesis of various N-substituted 1,2,3-triazoles by employing t-BuONa as the base promoter. Through a key Regitz diazo-transfer process with Tosyl azide, the reactions proceed efficiently at room temperature with good substrate tolerance
Julian P Henschke - One of the best experts on this subject based on the ideXlab platform.
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highly enantioselective rh catalyzed alkenylation of imines synthesis of chiral allylic amines via asymmetric addition of potassium alkenyltrifluoroborates to n Tosyl imines
ChemInform, 2014Co-Authors: Balraj Gopula, Chienwei Chiang, Way Zen Lee, Ting Shen Kuo, Julian P HenschkeAbstract:For the first time, simple N-Tosyl aryl aldimines are used as substrates in the rhodium catalyzed 1,2-addition reaction with alkenylboron nucleophiles.
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highly enantioselective rh catalyzed alkenylation of imines synthesis of chiral allylic amines via asymmetric addition of potassium alkenyltrifluoroborates to n Tosyl imines
Organic Letters, 2014Co-Authors: Balraj Gopula, Chienwei Chiang, Way Zen Lee, Ting Shen Kuo, Julian P HenschkeAbstract:For the first time, simple N-Tosyl aryl aldimines, prepared from the condensation of Tosyl amide and aromatic aldehydes, can be used as substrates in the rhodium catalyzed 1,2-addition reaction using alkenylboron nucleophiles. In the presence of 1.5 mol % of [RhCl(1e)]2, enantioselective addition of various potassium alkenyltrifluoroborates to aryl aldimines furnished the corresponding chiral allylic amines in 73–96% yield and 72–>99.5% ee. Notably, this method efficiently provides the di-, tri-, and tetrasubstituted allylic N-Tosyl amines with high asymmetric induction.
Zhen Yang - One of the best experts on this subject based on the ideXlab platform.
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concise stereoselective synthesis of oxaspirocycles with 1 Tosyl 1 2 3 triazoles application to the total syntheses of tuberostemospiroline and stemona lactam r
Chemistry: A European Journal, 2014Co-Authors: Junkai Fu, Hongjuan Shen, Yuanyuan Chang, Chuangchuang Li, Jianxian Gong, Zhen YangAbstract:: A 4-substituted-1-Tosyl-1,2,3-triazole-based stereoselective synthesis of structurally diverse oxaspirocycles is reported. The synthesis involves Rh-catalyzed loss of nitrogen from 4-substituted-1-Tosyl-1,2,3-triazoles, Grignard reaction, and a ring-closing metathesis reaction as key steps. By employing readily available and stable 4-substituted-1-Tosyl-1,2,3-triazoles as surrogates of diazo compounds and nitrogen sources, two types of oxaspirocycles were obtained. The latter compounds, which contain adjacent nitrogen stereocenters, could serve as the core structures of many natural products. This chemistry has been successfully applied to the total syntheses of (±)-tuberostemospiroline and (±)-stemona-lactam R.
Anatoly D Shutalev - One of the best experts on this subject based on the ideXlab platform.
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synthesis of functionalized pyridine derivatives by an amidoalkylation staudinger aza wittig sequence
Tetrahedron Letters, 2012Co-Authors: Anastasia A Fesenko, Anatoly D ShutalevAbstract:Abstract A new efficient methodology for the preparation of 3,4-difunctionalized pyridine derivatives by an amidoalkylation/Staudinger/aza-Wittig sequence has been developed. The synthesis includes condensation of 3-azidopropanal with urea and p-toluenesulfinic acid followed by reaction of the N-[(3-azido-1-Tosyl)propyl]urea obtained with Na-enolates of Tosylacetophenone or acetyl acetone to give N-[(5-azido-1-oxo-1-phenyl-2-Tosyl)pent-3-yl]urea and 5-acetyl-6-(2-azidoethyl)-4-hydroxy-4-methylhexahydropyrimidin-2-one, respectively. These compounds are transformed into 6-phenyl-5-Tosyl-4-ureido- and 5-acetyl-6-methyl-4-ureido-1,2,3,4-tetrahydropyridines by treatment with PPh3. The former is aromatized under the action of MnO2 or reduced by NaBH4/CF3COOH system to provide 2-phenyl-3-Tosylpyridine and 2-phenyl-3-Tosyl-4-ureidopiperidine.
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nucleophile mediated ring expansion of 4 chloromethyl and 4 mesyloxymethyl 5 Tosyl 1 2 3 4 tetrahydropyrimidin 2 ones to 6 Tosyl 2 3 4 5 tetrahydro 1h 1 3 diazepin 2 ones effect of the leaving group and the substituent at c6
Tetrahedron, 2011Co-Authors: Anastasia A Fesenko, Anatoly D ShutalevAbstract:Abstract A five-step synthesis of 4-chloromethyl- and 4-mesyloxymethyl-5-Tosyl-1,2,3,4-tetrahydropyrimidin-2-ones has been developed. The reaction of N -[(2-benzoyloxy-1-Tosyl)ethyl]urea with sodium enolates of α-Tosylketones followed by cyclization–dehydration, and debenzoylation gave 4-hydroxymethyl-5-Tosyl-1,2,3,4-tetrahydropyrimidin-2-ones, which were transformed into the 4-chloromethyl- or 4-mesyloxymethyl-derivatives. Treatment of the latter with nucleophilic reagents, such as sodium cyanide, sodium diethyl malonate, sodium thiophenolate, or potassium phthalimide, afforded the corresponding 4,7-disubstituted 6-Tosyl-2,3,4,5-tetrahydro-1 H -1,3-diazepin-2-ones as a result of ring expansion. The effect of the leaving group and the substitution at the position C6 on the reactivity of the pyrimidines is discussed.