- Facile functionalization of HTC-derived carbon microspheres
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Surfaces of HTC-derived carbons were functionalized using dienophiles such as maleimide (MI), tetracyanoethylene (TCNE), and 4,5-dicyano-1,3-dithiol-2-one (DCDTO). DCDTO-functionalized carbons were then hydrolyzed to yield thiol-functionalized carbons, wh
- Urakami, Hiromitsu,Antonietti, Markus,Vilela, Filipe
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- Kinetic Resolution of Sulfinamides via Asymmetric N-Allylic Alkylation
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An efficient kinetic resolution of sulfinamides via an asymmetric N-allylic alkylation reaction was realized using hydroquinine as a catalyst under mild conditions. The kinetic resolution of a range of Morita-Baylis-Hillman adducts and N-aryl tert-butylsulfinamides was highly effective. In addition, the synthetic utility of the protocol was demonstrated by a scaled-up reaction. Density functional theory calculations provide convincing evidence for the interpretation of stereoselection.
- Zheng, Gao-Liang,Lu, Chenxi,Cheng, Jin-Pei,Li, Xin
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supporting information
p. 8499 - 8504
(2021/10/25)
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- Asymmetric Michael addition of malonic diesters to acrylates by phase-transfer catalysis toward the construction of quaternary stereogenic α-carbons
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A highly enantioselective construction of an all-carbon quaternary stereogenic center at the α-position of malonic diesters has been achieved by Michael addition using phase-transfer catalysis. The reaction of α-monosubstituted malonates with acrylates in
- Odanaka, Yuki,Kanemitsu, Takuya,Iwasaki, Kanako,Mochizuki, Yukiko,Miyazaki, Michiko,Nagata, Kazuhiro,Kato, Masaru,Itoh, Takashi
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supporting information
p. 209 - 219
(2018/12/11)
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- Light- and heat-triggered reversible luminescent materials based on polysiloxanes with anthracene groups
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In this study, reversible silicone elastomers were successfully developed by light-triggered dimerization and heat depolymerization of the anthryl groups. Polysiloxanes with anthryl groups were prepared from poly(aminopropylmethylsiloxane) (PAPMS) with electron-donating (9-anthracenylmethyl acrylate) and electron-withdrawing (anthracene-9-carboxylic acid) units. The cross-linking networks were formed with the via 4π-4π photo-cycloadditions of the anthryl groups upon the UV light excitation (365 nm). 9-Anthracenylmethyl acrylate or anthracene-9-carboxylic acid efficiently dimerized through the photodimerization of the anthryl groups in the organic solvents, which was proven by UV-vis spectra, NMR spectra, and LC/MS. The covalent bonds between pendant anthryl groups were cleaved after heating at 120 °C. Furthermore, repeatable dimerization-depolymerization conversion was confirmed. In addition, for the first time, we found that the sunlight can also initiate the cycloaddition, which was "greener" and more environment-friendly. The green luminescence was observed from the PAPMS-1 film instead of the quenching effect caused by aggregation after the cycloaddition. Thus, a colorful UV-light emitting diode (LED) cell was obtained by coating the films on the commercially available LED cell.
- Han, Dongdong,Lu, Hang,Li, Wensi,Li, Yonghao,Feng, Shengyu
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p. 56489 - 56495
(2017/12/27)
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- Rotaxanes of a macrocyclic ferrocenophane with dialkylammonium axle components
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Octaoxa[22]ferrocenophane, 1, was synthesized and employed as the macrocyclic component of [2]rotaxanes. [2]Pseudorotaxanes composed of macrocyclic molecule 1 and dialkylammonium derivatives with a terminal vinyl group undergo end-capping via cross-metathesis of the terminal group with bulky acrylates. The [2]rotaxanes of 1 with axle components having bulky terminal groups, such as 3,5-dimethylphenyl, 9-anthryl, and ferrocenyl groups, maintain an interlocked structure in CDCl3 solution, but they are gradually converted into a mixture of the individual components via dethreading of the end groups in polar solvents such as CD3CN and dmso-d6. The reaction rate varies depending on the end group and solvent. The cationic rotaxane with an anthryl end group of the axle component, [(1){AnCH 2NH2CH2C6H4-4-OCH 2CH2CHCHCOOC6H4-4-C(C 6H4-4-tBu)3}](BArF) (An = 9-anthryl, BArF = B{C6H3-3,5-(CF3) 2}4) shows weak emission upon excitation of the anthryl group (12b, λem = 419 nm, quantum yield, = 0.012). The quantum yield is lower than that of the neutral rotaxane 13b ( = 0.030) formed by N-acetylation of 12b and a physical mixture of the corresponding free axle molecule, AnCH2N(Ac)CH2C6H4-4- OCH2CH2CHCHCOOC6H4-4-C(C 6H4-4-tBu)3 (8), and 1 ( = 0.34). The efficiency of the quenching caused by the ferrocenylene group caused by energy transfer is affected significantly by the relative positions of the anthryl and ferrocenylene groups in the rotaxane. The rotaxane with axles having a secondary ammonium moiety has a redox potential E1/2 = -0.03-0.02 V (vs. Ag+/Ag), which is lower those of than compound 1 (E1/2 = -0.10 V) and the neutral [2]rotaxanes with the N-acetylated axle components (E1/2 = -0.11 and -0.22 V). The Royal Society of Chemistry 2009.
- Suzaki, Yuji,Chihara, Eriko,Takagi, Atsuko,Osakada, Kohtaro
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supporting information; experimental part
p. 9881 - 9891
(2010/03/04)
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