- Metal-free synthesis of imidazole by BF3·Et2O promoted denitrogenative transannulation of N-sulfonyl-1,2,3-triazole
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BF3·Et2O promoted metal-free denitrogenative transannulation of N-sulfonyl-1,2,3-triazole was reported. Rather than transition metals, BF3·Et2O was employed for the first time to promote the formation of α-diazoimines from N-sulfonyl-1,2,3-triazoles in nitriles, leading to the synthesis of various imidazoles. The protocol tolerates a broad range of functional groups and could also be applied to the late-stage modification of bioactive molecules, demonstrating the potential of this protocol in organic synthesis. A plausible mechanism was proposed.
- Yang, Dongdong,Shan, Lihong,Xu, Ze-Feng,Li, Chuan-Ying
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p. 1461 - 1464
(2018/03/08)
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- POLYMERIZABLE COMPOUND AND OPTICAL ANISOTROPIC MATERIAL
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PROBLEM TO BE SOLVED: To provide a polymerizable compound which has high storage stability without inducing crystallization or the like when added to a polymerizable composition, to provide a polymerizable composition containing the polymerizable compound, which gives little haze or unevenness when a polymer is produced by polymerizing the polymerizable composition, and which hardly causes reduction in retardation when the polymer is heat treated, and further, to provide a polymer obtained by polymerizing the polymerizable composition, and an optical anisotropic material using the polymer. SOLUTION: A compound expressed by general formula (I) is provided; and also provided are a composition containing the above compound, a polymer obtained by polymerizing the composition, and an optical anisotropic material using the polymer. COPYRIGHT: (C)2015,JPOandINPIT
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- COMPOUNDS AND COMPOSITIONS AS TLR ACTIVITY MODULATORS
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The invention provides a novel class of compounds, pharmaceutical compositions comprising such compounds and methods of using such compounds to treat or prevent diseases or disorders associated with Toll-Like Receptors, including TLR7 and TLR8. In one aspect, the compounds are useful as adjuvants for enhancing the effectiveness of a vaccine (formula I) wherein: X3 is N; X4 is N Or CR3; X5 is -CR4=CR5.
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Page/Page column 198
(2009/10/22)
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- Sonogashira coupling reaction with diminished homocoupling
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(Matrix presented) The side product from homocoupling reaction of two terminal acetylenes in the Sonogashira reaction can be reduced to about 2% using an atmosphere of hydrogen gas diluted with nitrogen or argon. Terminal arylethynes, diarylethynes, and a few new arylpyridylethynes with donor substituents have been synthesized in very good yields. Comparative control experiments suggest that the homocoupling yield is determined by concentration of both catalyst and oxygen.
- Elangovan, Arumugasamy,Wang, Yu-Hsiang,Ho, Tong-Ing
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p. 1841 - 1844
(2007/10/03)
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- Choix des methodes pour la synthese univoque de carbures acetyleniques. Troisieme partie : Arylacetylenes et aryl-1 alcynes-1
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The range of applicability of six syntheses of pure alkynes with one aryl group has been defined; a short review of other possible procedures is included.We have specified the best method to obtain selectively the alkynes Ar-CCH and Ar-CC-R, according to the nature of the substituents of the aryl group and according to the developed structure of the R group.It is thus possible to recommend with the largest probability of success the method to obtain, in homogenous series, alkynes corresponding to still more complicated structures.
- Mesnard, Danielle,Bernadou, Francoise,Miginiac, Leone
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p. 3216 - 3245
(2007/10/02)
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- Vinyl Cation Intermediates in Solvolytic and Electrophilic Reactions. 1. Solvolysis of α-Arylvinyl Derivatives
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The solvolysis of 16 α-arylvinyl tosylates, bromides, and chlorides has been investigated in various alcohol-water mixtures and in acetic acid at several temperatures.All substrates were substituted with either 2-methyl or 2,6-dimethyl groups to accelerate the rates of reaction.The major or exclusive product isolated in most cases was the acetophenone arising from hydrolysis of the expected enol ethers or acetates during workup.The kinetics were simple first order in the vast majority of cases, with excess base added to prevent side reactions.Leaving group effects, Winstein-Grunwald m values, Schleyer Q values, and effects of solvent nucleophilicity all point to a limiting SN1 ionization generating a vinyl cation intermediate, in which there is little rear-side nucleophilic assistance by solvent.Substituent effects led to ρ values in the range -3.9 to -5.3 vs. ?+.Activation parameters are typical for an SN1 process, and ΔS% is insensitive to the presence of zero, one, or two o-methyl groups, as are the effects of solvent polarity on the rates.The results should therefore be directly comparable with other solvolytic or electrophilic reactions generating formally similar vinyl cation intermediates.
- Yates, Keith,Mandrapilias, George
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p. 3892 - 3902
(2007/10/02)
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