- Rh(III)-Catalyzed Chemodivergent Annulations between Indoles and Iodonium Carbenes: A Rapid Access to Tricyclic and Tetracyclic N-Heterocylces
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Herein, we report an acid-controlled highly tunable selectivity of Rh(III)-catalyzed [4 + 2] and [3 + 3] annulations of N-carboxamide indoles with iodonium ylides lead to form synthetically important tricyclic and tetracyclic N-heterocycles. Here, iodonium ylide serves as a carbene precursor. The protocol proceeds under operationally simple conditions and provides novel tricyclic and tetracyclic scaffolds such as 3,4-dihydroindolo[1,2-c]quinazoline-1,6(2H,5H)-dione and 1H-[1,3]oxazino[3,4-a]indol-1-one derivatives with a broad range of functional group tolerance and moderate to excellent yields. Furthermore, the protocol synthetic utility was extended for various chemical transformations and was easily scaled up to a large-scale level.
- Kanchupalli, Vinaykumar,Kumar, Sanjeev,Nanduri, Srinivas,Nunewar, Saiprasad,Pandhare, Harishchandra
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supporting information
p. 4233 - 4238
(2021/06/28)
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- Rh(iii)-Catalyzed C(sp2)-H functionalization/cyclization cascade of: N -carboxamide indole and iodonium reagents for access to indoloquinazolinone derivatives
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A rhodium-catalyzed synthesis of indoloquinazolinone from a readily available hypervalent iodonium reagent and N-carboxamide indole was developed. The protocol features broad functional group tolerance, mild conditions, and excellent yields. The target products were obtained simply by filtration, without tedious column chromatography. Notably, the noble metal catalyst system can be recycled effectively at least ten times. The strategy may be amenable to industrial production.
- Han, Zhi-Peng,Ji, Shun-Jun,Xu, Meng-Meng,Xu, Xiao-Ping,Zhang, Rui-Ying
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supporting information
p. 6337 - 6340
(2021/09/10)
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- Iodonium Ylides as Carbene Precursors in Rh(III)-Catalyzed C-H Activation
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The rhodium(III)-catalyzed coupling of C-H substrates with iodonium ylides has been realized for the efficient synthesis of diverse cyclic skeletons, where the iodonium ylides have been identified as efficient and outstanding carbene precursors. The reaction systems are applicable to both sp2 and sp3 C-H substrates under mild and redox-neutral conditions. The catalyst loading can be as low as 0.5 mol % in a gram-scale reaction. Representative products exhibit cytotoxicity toward human cancer cells at nanomolar levels.
- Jiang, Yuqin,Li, Pengfei,Li, Xingwei,Liu, Bingxian,Zhao, Jie
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supporting information
p. 7475 - 7479
(2020/10/12)
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- Support-Free Pd3Co NCs as an Efficient Heterogeneous Nanocatalyst for New Organic Transformations of C?C Coupling Reactions
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A support-free heterogeneous Pd3Co nanostructured composite (NC), synthesized through a hydrothermal route, acted as an effective catalytic system in multivariate Heck-, Sonogashira-, and Suzuki-type coupling reactions of iodonium ylides. The XPS analysis of the bimetallic Pd3Co NCs confirmed the elemental composition as 75 % palladium and 25 % cobalt. Furthermore, high-resolution (HR) TEM analysis confirmed the spherical morphology of the Pd3Co bimetallic nanoparticles. The average diameter of the NCs is 14.8 nm. The coupling reaction proceeded through the generation of α-iodoenones with simultaneous migration of the phenyl group, thereby giving a scaffold with higher atom economy. The heterogeneous Pd3Co NCs were recycled and reused without any significant change in catalytic ability for up to five reaction cycles. The high concentration of Pd and association of cobalt into the lattice of palladium appears to enhance its catalytic ability for the diverse coupling reactions in comparison with its monometallic counterparts as well as with bimetallic NCs with a comparatively lesser amount of Pd.
- Pradhan, Samjhana,Mishra, Kanchan,Lee, Yong Rok
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supporting information
p. 10886 - 10894
(2019/08/02)
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- Fused dihydrofurans from the one-pot, three-component reaction of 1,3-cyclohexanedione, iodobenzene diacetate and alkenes
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The one-pot, three-component reactions of substituted 1,3- cyclohexanediones, iodobenzene diacetate and alkenes, under photochemical activation, yields fused dihydrofuran derivatives in good yield via the in situ formation of iodonium ylides.
- Kalpogiannaki, Dimitra,Martini, Catherine-Irene,Nikopoulou, Aggeliki,Nyxas, John A.,Pantazi, Vassiliki,Hadjiarapoglou, Lazaros P.
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p. 1566 - 1575
(2013/02/25)
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- Study on anti-proliferative effect of benzoxathiole derivatives through inactivation of NF-κB in human cancer cells
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To investigate the anti-proliferative effect of a newly discovered NF-kB inhibitor, 6,6-dimethyl-2-(phenylimino)-6,7-dihydrobenzo[d][1,3]oxathiol-4(5H)- one (1a), a series of its analogs (1b-n) were prepared and evaluated for their NF-κB inhibition and anti-proliferative activity against various human cancer cell lines. Slight variation of hydrophobicity by replacement of dimethyl group of 1a at 6-position with bulky isopropyl group and introduction of para-fluoro substitution on 2-phenyl group showed good NF-κB inhibitory activity and anti-proliferative activity. However, excessive increase in hydrophobicity with 2,4,6-trichloro substituents on phenyl group resulted in the loss of both the activities. From the SAR results, 2-phenylimino-6,7- dihydrobenzo[d][1,3]oxathiol-4(5H)-one was identified as the lead scaffold for investigating new anticancer agent through inactivation of NF-κB.
- Venkateswararao, Eeda,Anh, Hoang Le Tuan,Sharma, Vinay K.,Lee, Ki-Cheul,Sharma, Niti,Kim, Youngsoo,Jung, Sang-Hun
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supporting information; experimental part
p. 4523 - 4527
(2012/08/07)
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- The question of electrophilic vs nucleophilic addition of cyclic β-dicarbonyl phenyliodonium ylides: Electrophilic cycloaddition of diphenylketene
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The reaction of β-dicarbonyl phenyliodonium ylides with diphenylketene at room temperature affords mixtures of lactone and aurone derivatives. The initial electrophilic attack of the iodonium ylide on the Cβ position of the diphenylketene, followed by cyclization of the zwitterionic species, and subsequent ejection of iodobenzene, affords the lactone and aurone cycloadducts. Treatment of β-dicarbonyl iodonium ylides with acyl chlorides yields α-chloroenones with good to excellent yields.
- Antos, Anna,Elemes, Yiannis,Michaelides, Adonis,Nyxas, John A.,Skoulika, Stavroula,Hadjiarapoglou, Lazaros P.
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p. 10949 - 10954
(2013/03/13)
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