- Sunlight-promoted cyclization: Versus decarboxylation in the reaction of alkynoates with N -iodosuccinimide: Easy access to 3-iodocoumarins
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A sunlight-initiated radical conversion of aryl alkynoates to 3-iodocoumarins has been achieved using N-iodosuccinimide as the iodine source without the use of a catalyst or additive. Experimental, X-ray analysis, and computational studies indicate that the reaction under sunlight proceeds through iodination, spirocyclization and ring expansion to form the kinetic product. The sunlight-driven reaction provides a green pathway to especially valuable 3-halocoumarins derivatives.
- Ni, Shengyang,Cao, Jia,Mei, Haibo,Han, Jianlin,Li, Shuhua,Pan, Yi
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- A visible-light-induced “on-off” one-pot synthesis of 3-arylacetylene coumarins with AIE properties
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A mild and simple one-pot stepwise method to synthesize 3-arylacetylene coumarins from alkynoates was demonstrated. This catalytic system involves photosensitizer-free photocatalysis and thermocatalysis processes. A series of alkynoates and phenylacetylenes were well tolerated in the optimized multi-catalytic system. The corresponding 3-arylacetylene coumarins were obtained in moderate to excellent yields. The results of the studies of their optical properties showed that the aromatic ring at the C4-position of coumarins is unfavorable for improving the molecular fluorescence quantum yield in solution. Based on the spectral studies and X-ray single crystal diffraction analysis, it was found that AIE activities may exist in some of the 3-arylvinyl-4-aryl-coumarins in their solid state. We expect that these molecules may have potential optical applications.
- Huang, Mengmeng,Jia, Ming,Kim, Jung Keun,Li, Yabo,Liu, Junkai,Wu, Xinjie,Wu, Yangjie,Xi, Jinhu,Zhao, Zheng
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p. 3346 - 3353
(2020/05/14)
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- Photoinduced cyclization of alkynoates to coumarins with N-Iodosuccinimide as a free-radical initiator under ambient and metal-free conditions
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An efficient photoinduced strategy for the preparation of coumarins was developed. In the presence of N-iodosuccinimide (NIS) as a free-radical initiator and under LED (380–385 nm) irradiation and metal-free conditions, the reaction of alkynoates underwen
- Wang, Zhihui,Li, Xuezhi,Wang, Lei,Li, Pinhua
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p. 1044 - 1051
(2019/01/25)
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- One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na2S2O8
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Various 4-aryl-3-bromocoumarins were smoothly obtained in moderate yields in one pot by treating 3-aryl-2-propynoic acids with diaryliodonium triflates and K2CO3 in the presence of CuCl, followed by the reaction with tetrabutylammoni
- Sasaki, Teppei,Moriyama, Katsuhiko,Togo, Hideo
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p. 345 - 353
(2018/02/19)
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- Hypervalent iodine compound containing heterocyclic ring as well as preparation method and application thereof
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The invention discloses a hypervalent iodine compound containing a heterocyclic ring as well as a preparation method and application thereof. A structure of the compound is shown as a formula (I): theformula (I) is shown in the description, wherein R is selected from hydrogen, halogen, alkyl, alkoxy, halogenated alkyl, halogenated alkoxy, nitryl, cyano, hydroxyl or -COOR'; R' is alkyl or halogenated alkyl; and Het is substituted or non-substituted 1,4-benzopyranone, substituted or non-substituted quinolone, substituted or non-substituted isoquinoline, substituted or non-substituted thiobenzopyranone, substituted or non-substituted coumarin and substituted or non-substituted oxepin. The compound disclosed by the invention is novel in structure and is the hypervalent iodine compound containing the heterocyclic ring; the hypervalent iodine compound is stable in structure and simple in preparation method; and meanwhile, the hypervalent iodine compound has a very good inhibition effect onML-1 and MOLM-13 cells and has an extremely great application prospect on prevention and/or treatment effect on leukemia.
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Paragraph 0178; 0179; 0181
(2019/01/08)
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- Heterocyclic Iodoniums for the Assembly of Oxygen-Bridged Polycyclic Heteroarenes with Water as the Oxygen Source
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A diverse set of novel heterocyclic iodoniums was synthesized for the first time. The reactions of these unique iodoniums with environmentally benign water as the oxygen source provided structurally complex oxygen-incorporated heteropolycycles that are essential motifs in natural products and biologically active compounds. The transformation only required low-cost copper acetate. Further derivatization of the obtained polycycles expanded the structural diversity, which is important in the building of chemical libraries for drug discovery.
- Zhu, Daqian,Wu, Zhouming,Luo, Bingling,Du, Yongliang,Liu, Panpan,Chen, Yunyun,Hu, Yumin,Huang, Peng,Wen, Shijun
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supporting information
p. 4815 - 4818
(2018/08/24)
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- Direct Preparation of 3-Iodochromenes from 3-Aryl- and 3-Alkyl-2-propyn-1-ols with Diaryliodonium Salts and NIS
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On the basis of a study of the O-phenylation of 3-phenyl-2-propyn-1-ol with diphenyliodonium triflate and t-BuONa, a variety of 4-aryl-3-iodo-2H-benzopyrans were prepared in good to moderate yields in one pot from the reaction of 3-aryl-2-propyn-1-ols wit
- Sasaki, Teppei,Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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supporting information
p. 944 - 947
(2016/03/15)
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- Synthesis of substituted 3-iodocoumarins and 3-iodobutenolides via electrophilic iodocyclization of ethoxyalkyne diols
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A convenient and general synthesis of various 4-substituted 3-iodocoumarins and 4,5-disubstituted 3-iodobutenolides is described via an exclusive 6-endo-dig iodocyclization of 3-ethoxy-1-(2-alkoxyphenyl)-2-yn-1-ols and 5-endo-dig iodocyclization of 1-alkoxy-4-ethoxy-3-yn-1,2-diols, respectively. The reaction is carried out under very mild conditions using I2 in CH2Cl2 or toluene at room temperature. Oxygens in OMe and OMOM groups were used as efficient nucleophiles for this intramolecular cyclization to obtain the products in good to excellent yields.
- Reddy, Maddi Sridhar,Thirupathi, Nuligonda,Hari Babu, Madala,Puri, Surendra
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p. 5878 - 5888
(2013/07/26)
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