- Partial deoxygenation of glycerol catalyzed by iridium pincer complexes
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Iridium pincer complexes (POCOP)Ir(CO) (POCOP = κ3-C 6H3-1,3-[OP(tBu)2]2) and substituted POCOP derivatives catalyze deoxygenation of glycerol to n-propanol and 1,3-propanediol in good yield under moderate conditions (acidic aqueous dioxane, 200 C, 80 bar H2). Catalyst solubility in the polar reaction mixture is improved by incorporation of a polar moiety in the para position of the POCOP phenyl ring, with the best results obtained with a dimethylamino substituent.
- Lao, David B.,Owens, Alisa C. E.,Heinekey, D. Michael,Goldberg, Karen I.
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- An Indirect Synthetic Approach toward Conformationally Constrained 20-Membered Unclosed Cryptands via Late-Stage Installation of Intraannular Substituents
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A new protocol for PTC-mediated O-alkylation of the intraannular position of 20-membered unclosed cryptands (UCs) is reported. In contrast to the classical, "direct" strategy, which requires functionalization of the lariat arm at the beginning of synthesis, this "indirect" approach enables the late-stage introduction of various benzylic substituents after an unfavorable macrocyclization step (11 examples, yields up to 98%). Notably, this method permits preparation of, previously inaccessible, crowded UCs bearing 1-acetylpyrene substituent and dimer joined by p-xylene linker.
- Jurczak, Janusz,Sobczuk, Adam,Dabrowa, Kajetan,Lindner, Marcin,Niedba?a, Patryk
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- Hydrodabcyl: A Superior Hydrophilic Alternative to the Dark Fluorescence Quencher Dabcyl
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Dark fluorescence quenchers are nonfluorescent dyes that can modulate the fluorescence signal of an appropriate fluorophore donor in a distance-dependent manner. Dark quenchers are extensively used in many biomolecular analytical applications, such as studies with fluorogenic protease substrates or nucleic acids probes. A very popular dark fluorescence quencher is dabcyl, which is a hydrophobic azobenzene derivative. However, its insolubility in water may constitute a major drawback, especially during the investigation of biochemical systems whose natural solvent is water. We designed and synthesized a new azobenzene-based dark quencher with excellent solubility in aqueous media, which represents a superior alternative to the much-used dabcyl. The advantage of hydrodabcyl over dabcyl is exemplarily demonstrated for the cleavage of the fluorogenic substrate hydrodabcyl-Ser-Phe-EDANS by the proteases thermolysin and papain.
- Kempf, Oxana,Kempf, Karl,Schobert, Rainer,Bombarda, Elisa
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p. 11893 - 11897
(2017/11/30)
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- HYDRODABCYL
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A new azobenzene-based fluorescence quencher with excellent solubility in aqueous solution is described here. This compound represents an optimized alternative to dabcyl in a variety of biomolecular applications, like fluorogenic protease substrates or nu
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Page/Page column 12
(2016/06/14)
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- Sensing acetylcholine and anticholinesterase compounds
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Acetylcholine is a key neurotransmitter, and anticholinesterase agents are essential compounds used as medical drugs, pesticides, and chemical warfare agents. A semisynthetic fluorescence-based probe for the direct, real-time detection of acetylcholine and anticholinesterase compounds is introduced. The probe possesses good sensitivity, tunable detection range, and can be selectively targeted to cell surfaces, thereby making it an attractive tool for applications in analytical chemistry and quantitative biology.
- Schena, Alberto,Johnsson, Kai
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supporting information
p. 1302 - 1305
(2014/03/21)
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