- Lewis Acid Regulated Divergent Catalytic Reaction between Quinone Imine Ketals (QIKs) and 1,3-Dicarbonyl Compounds: Switchable Access to Multiple Products Including 2-Aryl-1,3-Dicarbonyl Compounds, Indoles, and Benzofurans
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A catalytic Lewis acid regulated reaction between quinone imine ketals (QIKs) and 1,3-dicarbonyl compounds provides a divergent and tunable approach to a variety of skeletons, including a series of 2-aryl-1,3-dicarbonyl compounds, indoles, and benzofurans. The use of lithium chloride and ferrous bromide gives C3- or C2-alkylation products of the QIKs. The combination of ferrous bromide and trifluoromethanesulfonic acid delivers indole derivatives. Sequential hydrolysis and C3-alkylation occur in the presence of ytterbium (III) trifluoromethanesulfonate and stoichiometric amounts of water. When the reaction is performed with trifluoromethanesulfonic acid and stoichiometric amounts of water, benzofuran is obtained. This protocol utilizes mild conditions, exhibits regio- and chemoselectivity, and has broad functional group tolerance. (Figure presented.).
- Chen, Xingyu,Lu, Sixian,Deng, Ping,Chang, Xiaoqiang,Zhao, Yifan,Ma, Yue,Zhang, Dong,Xia, Fei,Yang, Lan,Wang, Jigang,Sun, Peng
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supporting information
p. 94 - 102
(2021/10/05)
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- Lewis Base Promoted, Direct 1,4-Conjugate Addition to Quinone Imine Ketals: Efficient Access to Unsymmetrical Diaryl Sulfones
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An alternative approach with eco-friendliness and high efficiency for the preparation of unsymmetrical diaryl sulfones has been developed. The strategy takes advantage of the reaction of sulfonyl hydrazides with quinone imine ketals catalyzed by DABCO (triethylenediamine) in ethanol. This transformation proceeds via a Lewis base promoted, direct 1,4-conjugate addition/sulfonylation/alcohol elimination reaction sequence. The protocol provides an efficient approach to access an array of diverse unsymmetrical diaryl and heterodiaryl sulfones, aryl alkyl sulfones and aryl vinyl sulfones in good to excellent yields.
- Liu, Teng,Liu, Jianjun,Shen, Xianfu,Xu, Jianbin,Nian, Beifang,He, Ni,Zeng, Shunqun,Cheng, Feixiang
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p. 1365 - 1376
(2019/03/08)
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- Efficient N-acylation of sulfonamides using cesium salt of Wells–Dawson heteropolyacid as catalyst: Synthesis of new N-acyl sulfonamides and cyclic imides
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N-acylation of substituted sulfonamides with different anhydrides in the presence of Cesium salt of Wells–Dawson heteropolyacid (Cs5HP2W18O62) as an efficient and reusable catalyst was investigated for the first time. ?Cs5HP2W18O62 was used with a catalytic amount in water as a green solvent. At room temperature, a series of N-acylsulfonamides were synthesized, while under refluxing conditions, new cyclic imides containing sulfonyl group were obtained. Atom-economy, high yields, easy work-up, as well as simple catalyst recovery and reusability are the key features of this procedure.
- Benali, Nesma,Bougheloum, Chafika,Alioua, Sabrina,Belghiche, Robila,Messalhi, Abdelrani
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p. 3099 - 3112
(2018/12/04)
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- Copper-catalyzed cross-coupling of chloramine salts and arylboronic acids in water: A green and practical route to N-arylsulfonamides
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A green and practical method for the synthesis of N-arylsulfonamides from chloramine salts and arylboronic acids is herein developed. The reaction proceeds readily in the presence of 5 mol% of CuI and 2.5 equiv. K2CO3 in water at room temperature, generating a variety of N-arylsulfonamides in moderate to good yields with good functional group tolerance.
- Ouyang, Banlai,Zheng, Yanxia,Liu, Yi,Liu, Fei,Yao, Juying,Peng, Yiyuan
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p. 3694 - 3698
(2018/09/14)
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- Synthesis of N -Arylsulfonamides by a Copper-Catalyzed Reaction of Chloramine-T and Arylboronic Acids at Room Temperature
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A copper-catalyzed Chan-Lam-coupling-like reaction of a (het)arylboronic acid and chloramine-T (or a related compound) has been developed for the synthesis of N -arylsulfonamides at room temperature in moderate to good yields, with good tolerance of functional groups. In this process, it is believed that chloramine-T serves as an electrophile.
- Ouyang, Banlai,Liu, Deming,Xia, Kejian,Zheng, Yanxia,Mei, Hongxin,Qiu, Guanyinsheng
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supporting information
p. 111 - 115
(2017/12/27)
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- Differentiation of isomeric haloanilines by tosylation in combination with electrospray ionization mass spectrometry
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Differentiation of the isomeric haloanilines still remains a challenging and?necessary?analytic task due to their identical retention time in chromatography and similar mass spectra. In this work, p-tosylation of haloanilines by reaction of haloanilines with p-toluenesulfonyl chloride resulted in the corresponding N-tosyl haloanilines. Fragmentation of protonated N-tosyl haloanilines in electrospray ionization tandem mass spectrometry (ESI-MS/MS) mainly resulted in tosyl cation, haloaniline radical cation, and halohydroxyaniline radical cation. The MS/MS of the three group isomeric derivatives showed significant difference in abundance distribution of these product ions, respectively. Theoretical calculations showed that the stability of the ion-neutral complex (INC) is a key factor influencing the relative intensity of the product ions. The three group isomeric derivatives were also separated by high performance liquid chromatograph (HPLC) at conventional conditions. p-Tosylation combined tandem MS (or HPLC) technique were carried out to realize the differentiation of isomeric haloanilines.
- Wang, Shanshan,Cheng, Yuanyuan,Chen, Mengmeng,Jiang, Kezhi
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p. 337 - 343
(2018/07/31)
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- Direct C-H amidation of benzoic acids to introduce meta- and para-amino groups by tandem decarboxylation
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The Ir-catalyzed mild C-H amidation of benzoic acids with sulfonyl azides was developed to give reactions with high efficiency and functional-group compatibility. Subsequent protodecarboxylation of ortho-amidated benzoic acid products afforded meta- or para-substituted (N-sulfonyl)aniline derivatives, the latter being inaccessible by other C-H functionalization approaches. The decarboxylation step was compatible with the amidation conditions, enabling a convenient one-pot, two-step process. Without a trace: Carboxylic acids are used as traceless directing groups in the Ir-catalyzed direct C-H amidation of arenes with sulfonyl azides under mild conditions. The tandem protodecarboxylation of the ortho-amidated benzoic acid products afforded meta- or para-substituted (N-sulfonyl)anilines, which are difficult to obtain by other C-H functionalization approaches.
- Lee, Donggun,Chang, Sukbok
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p. 5364 - 5368
(2015/03/30)
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- Polymorphism in secondary benzene sulfonamides
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The role of about 20 different solvents in the crystallization of polymorphs for 13 N-phenyl benzene sulfonamides was studied. Five compounds (1, 2, 3, 7, and 11) are dimorphic, and one is trimorphic (6). All the crystalline solids were characterized by p
- Sanphui, Palash,Sarma, Bipul,Nangia, Ashwini
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experimental part
p. 4550 - 4564
(2011/12/22)
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