- Gold-catalyzed synthesis of 4-(2-Oxoalkoxy)butyl Methanesulfonates via ring-opening of tetrahydrofuran
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A variety of terminal alkynes were converted into the corresponding 4-(2-oxoalkoxy)butyl methanesulfonates via a gold-catalyzed intermolecular oxidation reaction using 8-ethylquinoline N-oxide as the oxidant and THF as the solvent. This reaction is proposed to proceed through the ring-opening of THF via an α-oxo gold carbene intermediate.
- Huang, Wangyong,Xiang, Jiannan,He, Weimin
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- Iridium(III)-Catalyzed Tandem Annulation of Pyridine-Substituted Anilines and α-Cl Ketones for Obtaining 2-Arylindoles
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A facile and expeditious protocol for the synthesis of 2-arylindole compounds from readily available N-(2-pyridyl)anilines and commercially available α-Cl ketones through iridium-catalyzed C-H activation and cyclization is reported here. As a complementary approach to the conventional strategies for indole synthesis, the transformation exhibits powerful reactivity, tolerates a large number of functional groups, and proceeds with good to excellent yields under mild conditions, providing a straightforward method to obtain structurally diverse and valuable indole scaffolds. Furthermore, the reaction could be easily scaled up to gram scale.
- Cui, Xin-Feng,Qiao, Xin,Wang, He-Song,Huang, Guo-Sheng
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p. 13517 - 13528
(2020/12/15)
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- Selective Asymmetric Transfer Hydrogenation of α-Substituted Acetophenones with Bifunctional Oxo-Tethered Ruthenium(II) Catalysts
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A practical method for the asymmetric transfer hydrogenation of α-substituted ketones was developed utilizing oxo-tethered N-sulfonyldiamine-ruthenium complexes. Reduction by HCO2H and HCO2K in a mixed solvent of EtOAc/H2O allowed for the selective synthesis of halohydrins from 2-bromoacetophenone (98%) and 2-chloroacetophenone (>99%), leading to suppressed undesired side reactions stemming from formylation under the typical reaction conditions using an azeotropic 5:2 mixture of HCO2H and Et3N. A range of functional groups, such as halogens, methoxy, nitro, dimethylamino, and ester groups, were well tolerated, highlighting the potential of this method. Nearly complete selectivity with a preferable ee was maintained even with a substrate/catalyst (S/C) ratio of 5000. This catalyst system was also effective for the asymmetric reduction of α-sulfonated ketones without eroding the leaving group. (Figure presented.).
- Yuki, Yamato,Touge, Taichiro,Nara, Hideki,Matsumura, Kazuhiko,Fujiwhara, Mitsuhiko,Kayaki, Yoshihito,Ikariya, Takao
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supporting information
p. 568 - 574
(2017/12/13)
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- Synthesis of α-sulfonyloxyketones via iodobenzene diacetate (PIDA)-mediated oxysulfonyloxylation of alkynes with sulfonic acids
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A simple yet powerful method to synthesize a variety of α-sulfonyloxyketones has been developed. This novel method can be applied for the direct oxysulfonyloxylation of alkynes with sulfonic acids to access a variety of α-sulfonyloxyketones. Compared to the reported methods for the application of PIDA, this study expands its application scope and uses it not only as the oxidant but also as the carrier of O to form the carbonyl group in the products. In addition, under the established conditions, this methodology not only exhibits a broad substrate scope but also demonstrates exclusive regioselectivity with substrates of 1,2-disubstituted internal alkynes.
- Zhang, Yang,Tan, Hua,Liu, Weibing
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p. 54017 - 54020
(2017/12/05)
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- One-step synthesis of methanesulfonyloxymethyl ketones via gold-catalyzed oxidation of terminal alkynes: A combination of ligand and counter anion enables high efficiency and a one-pot synthesis of 2,4-disubstituted thiazoles
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By using Mor-DalPhos as the P,N-bidentate ligand and mesylate as the counter ion, the resulting gold(I) complex catalyzes efficient oxidative transformations of various terminal alkynes into synthetically versatile methanesulfonyloxymethyl ketones. The mild reaction conditions and high efficiency permit the one-pot synthesis of a range of valuable 2,4-disubstituted thiazoles by subjecting the resulting reaction mixture to a further condensation with thioamides under mild conditions.
- Wu, Gongde,Zheng, Renhua,Nelson, Jonathan,Zhang, Liming
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supporting information
p. 1229 - 1234
(2014/05/06)
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- Oxidative breakdown of iodoalkanes to catalytically active iodine species: A case study in the α-tosyloxylation of ketones
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Catalysis of the oxidative processes by iodoarenes has become a promising direction in synthesis. The mechanism, involving the well-known isolable hypervalent iodine species, is generally limited to aromatic iodides, since the corresponding aliphatic spec
- Guo, Wusheng,Vallcorba, Oriol,Vallribera, Adelina,Shafir, Alexandr,Pleixats, Roser,Rius, Jordi
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p. 468 - 472
(2014/03/21)
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- Novel α-tosyloxylation of ketones catalyzed by the in situ generated hypoiodous acid from alkyl iodide
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Using a catalytic amount of 1-iodopropane, a novel and efficient procedure has been developed for direct preparation of α-tosyloxyketones from ketones. In this protocol, 1-iodopropane is first oxidized into iodosylpropane, which decomposes to form the key
- Zhang, Bijun,Han, Liuquan,Hu, Jiantao,Yan, Jie
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p. 5851 - 5854
(2015/01/16)
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- Effective α-tosyloxylation of ketones using 1,1,1-trifluoro-2-iodoethane as catalyst
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With 1,1,1-trifluoro-2-iodoethane as catalyst, a novel and efficient procedure has been developed for preparation of α-tosyloxyketones from ketones. In this protocol, 1,1,1-trifluoro-2-iodoethane is first oxidized by m-chloroperbenzoic acid to a hypervale
- Zhang, Bijun,Han, Liuquan,Hu, Jiantao,Yan, Jie
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supporting information
p. 3264 - 3270
(2015/10/06)
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- Straightforward and highly efficient synthesis of α-acetoxy ketones through gold-catalyzed intermolecular oxidation of terminal alkynes
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A variety of terminal alkynes were efficiently converted into the corresponding α-acetoxy ketones through gold-catalyzed intermolecular oxidation in the presence of 8-methylquinoline 1-oxide as the oxidant. The reaction probably proceeds through an α-oxo gold carbene intermolecular O-H insertion.
- Wu, Chao,Liang, Zhiwu,Yan, Dong,He, Weimin,Xiang, Jiannan
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p. 2605 - 2611
(2013/09/24)
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- Gold-catalyzed intermolecular oxidation of terminal alkynes: Simple and efficient synthesis of α-mesyloxy ketones
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A variety of terminal alkynes were efficiently converted into the corresponding α-mesyloxy ketones through gold-catalyzed intermolecular oxidation in the presence of 3,5-dichloropyridine N-oxide as the oxidant. The reaction is proposed to proceed via α-oxo gold carbene intermolecular O-H insertion. Georg Thieme Verlag Stuttgart · New York.
- Xie, Longyong,Liang, Zhiwu,Yan, Dong,He, Weimin,Xiang, Jiannan
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supporting information
p. 1809 - 1812
(2013/09/12)
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- Iodine-mediated α-sulfonyloxylation of alkyl aryl ketones with oxone and sulfonic acids
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Alkyl aryl ketones are converted into the corresponding α-sulfonyloxyketones, in moderate to excellent yields, via a novel procedure that utilizes Oxone, p-toluenesulfonic acid or methanesulfonic acid and molecular iodine in a mixture of aceton
- Kikui, Hiroki,Moriyama, Katsuhiko,Togo, Hideo
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p. 791 - 797
(2013/04/10)
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- Sol-gel immobilized aryl iodides for the catalytic oxidative α-tosyloxylation of ketones
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New hybrid silica materials M1-M4, derived from mono and bis-silylated aryl iodides, have been prepared via sol-gel processes, either by the hydrolytic polycondensation of a bis-silylated monomer or by the co-gelification of a monosilylated precursor with
- Guo, Wusheng,Monge-Marcet, Amàlia,Catto?n, Xavier,Shafir, Alexandr,Pleixats, Roser
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p. 192 - 199
(2013/02/25)
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- A novel one-pot method for αα-tosyloxylation of ketones using a catalytic amount of ammonium iodide
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A novel one-pot procedure was designed for the preparation of various α-tosyloxy ketones in good yields by the reaction of ketones with m-chloroperoxybenzoic acid and p-toluenesulfonic acid monohydrate in the presence of catalytic amounts of ammonium iodi
- Hu, Jiantao,Zhu, Min,Xu, Yuan,Yan, Jie
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experimental part
p. 1226 - 1232
(2012/05/20)
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- One-Pot Protocol for Synthesis of -Organosulfonyloxy Ketones from Secondary Alcohols Using Hypervalent Iodine(V)-Mediated Oxidations
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Tosyloxy ketones and -mesyloxy ketones were directly prepared from alcohols in one pot by treatment with hypervalent iodine(V) reagents in combination with p-toluenesulfonic acid and methanesulfonic acid, respectively, in moderate to good yields. Reaction
- Deshmukh, Swapnil S.,Huddar, Sameerana N.,Akamanchi, Krishnacharya G.
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experimental part
p. 3101 - 3110
(2009/11/30)
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- M-iodosylbenzoic acid: Recyclable hypervalent iodine reagent for-tosyloxylation and-mesyloxylation of ketones
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m-Iodosylbenzoic acid-mediated reactions of various carbonyl compounds provided-organosulfonyloxy carbonyl compounds in good yields. The final products could be easily isolated without any chromatographic purification by simple treatment of the crude mixt
- Yusubov, Mekhman S.,Funk, Tatyana V.,Yusubova, Roza Y.,Zholobova, Galina,Kirschning, Andreas,Park, Joo Yeon,Chi, Ki-Whan
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experimental part
p. 3772 - 3784
(2009/12/06)
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- A new application of hypervalent iodine (λ5) reagents with organosulfonic acids for direct α-organosulfonyloxylation carbonyl compounds
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Hypervalent iodine (λ5) reagents in combination with p-toluenesulfonic acid when reacted with ketones under reflux temperature in acetonitrile gave α-tosyloxy ketones in moderate to excellent yields. The reaction was developed further for both
- Mahajan, Ulhas S.,Akamanchi, Krishnacharya G.
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experimental part
p. 987 - 990
(2009/04/04)
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- PhI- and polymer-supported PhI-catalyzed oxidative conversion of ketones and alcohols to α-tosyloxyketones with m-chloroperbenzoic acid and p-toluenesulfonic acid
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Various ketones were converted to the corresponding α-tosyloxyketones with mCPBA and p-toluenesulfonic acid in the presence of a catalytic amount of iodobenzene. Moreover, secondary alcohols were directly converted to the corresponding α-tosyloxyketones using mCPBA and catalytic amounts of iodobenzene and potassium bromide, followed by treatment with p-toluenesulfonic acid in a one-pot manner. Poly(4-iodostyrene) could be also used as a recyclable catalyst for the same α-tosyloxylation of ketone.
- Yamamoto, Yukiharu,Kawano, Yuhta,Toy, Patrick H.,Togo, Hideo
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p. 4680 - 4687
(2007/10/03)
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- Hypervalent iodine oxidation: A facile access to α-thiocyanatoketones
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Aryl alkyl ketones (1) on treatment with benzene or benzene undergo oxidation via α-sulphonyloxyketones as intermediates to form α-thiocyanoketones (2) in excellent yields.
- Khanna, Mahavir S.,Sangeeta,Garg, Chandra P.,Kapoor, Ram P.
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- Reaction of benzene and benzene with Trimethylsilyl Enol Ethers. A New General Method for α-Sulfonyloxylation of Carbonyl Compounds
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Reaction of benzene (1) with trimethylsilyl enol ethers of aromatic ketones 4a-d, alicyclic ketone 7, aliphatic ketone 10, and esters 13a-c in dichloromethane at room temperature gives good yields of α-(tosyloxy)carbonyl compounds 5
- Moriarty, Robert M.,Penmasta, Raju,Awasthi, Alok K.,Epa, W. Ruwan,Prakash, Indra
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p. 1101 - 1104
(2007/10/02)
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