The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Chen Zheng - One of the best experts on this subject based on the ideXlab platform.
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hypervalent iodine mediated regioselective cyclization of acetylenic malonates facile synthesis of 1 diiodomethylene indane and cyclopentane derivatives
ChemInform, 2012Co-Authors: Chen ZhengAbstract:An intramolecular electrophilic cyclization of acetylenic malonates (I) and (III) with the combination of Iodosobenzene and Bu4NI in trifluoroethanol is developed.
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hypervalent iodine mediated regioselective cyclization of acetylenic malonates facile synthesis of 1 diiodomethylene indane and cyclopentane derivatives
Chemical Communications, 2011Co-Authors: Chen ZhengAbstract:A facile synthesis of potentially useful 1-diiodomethylene indanes and cyclopentanes from the regioselective cyclization of acetylenic malonates with the combination of Iodosobenzene with tetrabutylammonium iodide in 2,2,2-trifluoroethanol is reported.
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solvent controlled oxidative cyclization for divergent synthesis of highly functionalized oxetanes and cyclopropanes
Organic Letters, 2009Co-Authors: Yang Ye, Chen ZhengAbstract:An efficient solvent-controlled oxidative cyclization of Michael adducts of malonates with chalcones with the combination of Iodosobenzene and tetrabutylammonium iodide is reported. Highly functionalized oxetanes and cyclopropanes were divergently synthesized in moderate to excellent yields with high diastereoselectivity.
Chi Zhang - One of the best experts on this subject based on the ideXlab platform.
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boron trifluoride etherate functioning as a fluorine source in an Iodosobenzene mediated intramolecular aminofluorination of homoallylic amines
Organic Letters, 2014Co-Authors: Jian Cui, Shan-shan Liu, Qun Jia, Ruozhu Feng, Chi ZhangAbstract:A widely used Lewis acid BF3·Et2O was shown to be capable of acting as an efficient fluorinating agent in an intramolecular aminofluorination reaction of homoallylic amines to provide 3-fluoropyrrolidines mediated by a commercially available hypervalent iodine(III) reagent PhIO at room temperature. A mechanism involving a carbocation intermediate was proposed on the basis of several experimental evidence.
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A mild and efficient direct α-amination of β-dicarbonyl compounds using Iodosobenzene and p-toluenesulfonamide catalyzed by perchlorate zinc hexahydrate.
Organic Letters, 2012Co-Authors: Shan-shan Liu, Jian Cui, Xue-sen Hou, Chi ZhangAbstract:A direct α-amination of β-dicarbonyl compounds has been achieved by using Iodosobenzene (PhIO) as an oxidant and p-toluenesulfonamide (TsNH2) as an aminating reagent in the presence of a catalytic amount of perchlorate zinc hexahydrate. The present amination reaction proceeds quickly at rt (
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a mild and efficient direct α amination of β dicarbonyl compounds using Iodosobenzene and p toluenesulfonamide catalyzed by perchlorate zinc hexahydrate
Organic Letters, 2012Co-Authors: Jun Yu, Chi ZhangAbstract:A direct α-amination of β-dicarbonyl compounds has been achieved by using Iodosobenzene (PhIO) as an oxidant and p-toluenesulfonamide (TsNH2) as an aminating reagent in the presence of a catalytic amount of perchlorate zinc hexahydrate. The present amination reaction proceeds quickly at rt (<30 min needed for most tested substrates) to provide the corresponding α-N-tosylamido β-dicarbonyl compounds in high to excellent yields.
Robert H Dodd - One of the best experts on this subject based on the ideXlab platform.
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Rhodium-Catalyzed Intramolecular Formation of N-Sulfamoyl 2,3- Aziridino-γ-lactones and Their Use for the Enantiospecific Synthesis of α,β-Diamino Acid Derivatives
2016Co-Authors: Marcelo Siqueira Valle, Mauricio Frota Saraiva, Pascal Retailleau, Mauro V De Almeida, Robert H DoddAbstract:*S Supporting Information ABSTRACT: 4-Hydroxymethylbutenolide 4 was transformed into its sulfamoyl derivative 5, which upon treatment with Iodosobenzene diacetate and magnesium oxide in the presence of a rhodium catalyst afforded the product of intramolecular aziridination 6. Reaction of 6 with primary or secondary amines in DMA led to regioselective opening of the aziridine ring at C2 to give the corresponding bicyclic derivatives 7a−7g in good to excellent yields. Methanolysis of the lactone ring of the N-benzyl-N-methyl derivative 7c followed by protection of the resulting secondary hydroxy group and treatment of the product with Boc anhydride provided the activated cyclic sulfamates 13 and 14. The latter then reacted with a second nucleophile (azide or thiophenol) to give the corresponding difunctionalized α,β-diamino methyl esters 15−18, 20. 2,3-Aziridino-γ-lactones have been shown to be valuable starting materials for the preparation of α- and β-amino acids.1−5 Unlike the well-documented aziridino-2-carboxyli
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Rhodium-catalyzed intramolecular formation of N-sulfamoyl 2,3-aziridino-γ-lactones and their use for the enantiospecific synthesis of α,β-diamino acid derivatives.
Journal of Organic Chemistry, 2012Co-Authors: Marcelo Siqueira Valle, Mauricio Frota Saraiva, Pascal Retailleau, Mauro V De Almeida, Robert H DoddAbstract:4-Hydroxymethylbutenolide 4 was transformed into its sulfamoyl derivative 5, which upon treatment with Iodosobenzene diacetate and magnesium oxide in the presence of a rhodium catalyst afforded the product of intramolecular aziridination 6. Reaction of 6 with primary or secondary amines in DMA led to regioselective opening of the aziridine ring at C2 to give the corresponding bicyclic derivatives 7a-7g in good to excellent yields. Methanolysis of the lactone ring of the N-benzyl-N-methyl derivative 7c followed by protection of the resulting secondary hydroxy group and treatment of the product with Boc anhydride provided the activated cyclic sulfamates 13 and 14. The latter then reacted with a second nucleophile (azide or thiophenol) to give the corresponding difunctionalized α,β-diamino methyl esters 15-18, 20.
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Rhodium-Catalyzed Intramolecular Formation of N-Sulfamoyl 2,3-Aziridino-γ-lactones and Their Use for the Enantiospecific Synthesis of α,β-Diamino Acid Derivatives
2012Co-Authors: Marcelo Siqueira Valle, Pascal Retailleau, Mauricio Frota Saraiva, Mauro V. De Almeida, Robert H DoddAbstract:4-Hydroxymethylbutenolide 4 was transformed into its sulfamoyl derivative 5, which upon treatment with Iodosobenzene diacetate and magnesium oxide in the presence of a rhodium catalyst afforded the product of intramolecular aziridination 6. Reaction of 6 with primary or secondary amines in DMA led to regioselective opening of the aziridine ring at C2 to give the corresponding bicyclic derivatives 7a–7g in good to excellent yields. Methanolysis of the lactone ring of the N-benzyl-N-methyl derivative 7c followed by protection of the resulting secondary hydroxy group and treatment of the product with Boc anhydride provided the activated cyclic sulfamates 13 and 14. The latter then reacted with a second nucleophile (azide or thiophenol) to give the corresponding difunctionalized α,β-diamino methyl esters 15–18, 20
Dewen Dong - One of the best experts on this subject based on the ideXlab platform.
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oxidative cyclization of β aminoacrylamides mediated by phio chemoselective synthesis of isoxazoles and 2h azirines
Journal of Organic Chemistry, 2018Co-Authors: Jingwen Yuan, Qian Zhang, Chitturi Bhujanga Rao, Rui Zhang, Yanning Zhao, Bicheng Deng, Dewen DongAbstract:Cyclization of a variety of β-aminoacrylamides in the presence of Iodosobenzene (PhIO) is described. This process features mild reaction conditions, simple execution, and high chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of substituted isoxazoles and 2H-azirines via switchable N–O and N–C bond formation controlled by simply varying the β-substituent R3 of the readily available substrates.
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Oxidative Cyclization of β‑Aminoacrylamides Mediated by PhIO: Chemoselective Synthesis of Isoxazoles and 2H‑Azirines
2018Co-Authors: Jingwen Yuan, Qian Zhang, Chitturi Bhujanga Rao, Rui Zhang, Yanning Zhao, Bicheng Deng, Dewen DongAbstract:Cyclization of a variety of β-aminoacrylamides in the presence of Iodosobenzene (PhIO) is described. This process features mild reaction conditions, simple execution, and high chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of substituted isoxazoles and 2H-azirines via switchable N–O and N–C bond formation controlled by simply varying the β-substituent R3 of the readily available substrates
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Iodosobenzene-Mediated α‑Acyloxylation of 1,3-Dicarbonyl Compounds with Carboxylic Acids and Insight into the Reaction Mechanism
2018Co-Authors: Chitturi Bhujanga Rao, Jingwen Yuan, Qian Zhang, Rui Zhang, Ning Zhang, Jianyong Fang, Dewen DongAbstract:A highly efficient direct α-acyloxylation of 1,3-dicarbonyl compounds with carboxylic acids mediated by hypervalent iodine reagent is presented. Treatment of a variety of 1,3-dicarbonyl compounds with carboxylic acids in the presence of Iodosobenzene provides the corresponding α-acyloxylated products in good to excellent yields. The mechanistic investigation by means of NMR spectroscopy reveals that the in situ-generated phenyliodine biscarboxylate proves to be the key intermediate for the α-acyloxylation, and the loading sequence of reactants and oxidant is crucial for the generation of the active species. The mild reaction conditions, wide substrate scope, short reaction time, good yields, high chemoselectivity, excellent functional group tolerance, and metal catalyst-free conversion make this acyloxylation a significant synthetic protocol
Renhua Fan - One of the best experts on this subject based on the ideXlab platform.
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stereoselective synthesis of 2 carbamoyl 2 cyanocyclopropanecarboxylates by tandem oxidative cyclization and neighboring group assisted decarboxylation
Journal of Organic Chemistry, 2010Co-Authors: Hua Wang, Renhua FanAbstract:In this paper, we report a facile synthesis of 2-carbamoyl-2-cyanocyclopropanecarboxylates through a tandem Iodosobenzene/tetrabutylammonium iodide-induced oxidative cyclization and a subsequent neighboring group-assisted decarboxylation of the Michael adducts of 2-cyanoacetamides with α,β-unsaturated malonates. This method affords the desired highly functionalized cyclopropanes in moderate to good yields and with excellent diastereoselectivities. In addition, the reaction proceeds smoothly under mild conditions and with good functional group tolerance.
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aqueous iodine iii mediated stereoselective oxidative cyclization for the synthesis of functionalized fused dihydrofuran derivatives
Journal of Organic Chemistry, 2010Co-Authors: Linfei Wang, Renhua FanAbstract:An efficient aqueous oxidative cyclization mediated by the combination of Iodosobenzene with tetra-(n-butyl)ammonium iodide provides a new convenient and useful route to functionalized fused dihydrofuran derivatives in moderate to excellent yields with high diastereoselectivities.
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phio bu4ni mediated oxidative cyclization of amidoalkylation adducts for the synthesis of n benzoyl aziridines and oxazolines
Tetrahedron Letters, 2010Co-Authors: Renhua Fan, Hua Wang, Jianhong GanAbstract:An efficient oxidative cyclization of amidoalkylation adducts of activated methylene compounds with the combination of Iodosobenzene and a catalytic amount of tetrabutylammonium iodide under neutral conditions is reported. The reaction affords N-benzoyl aziridines or oxazolines in moderate to excellent yields.
