1689-64-1Relevant articles and documents
Visual sensing of Ca2+ ion via photoreaction of fluorenyl ester-armed cyclen
Player, Tomoko N.,Shinoda, Satoshi,Tsukube, Hiroshi
, p. 1615 - 1616 (2005)
Fluorenyl ester-armed cyclen gave fluorenone and related decomposition compounds upon photoirradiation. The reaction was effectively suppressed by the formation of an octacoordinated Ca2+ complex while Na+ and other alkali/alkaline earth metal cations had little influence. Since the production efficiency of fluorescent fluorenone related well to the concentration of the Ca2+ ion, the photoreaction of this armed cyclen offered the naked-eye detection of Ca2+ ion in aqueous samples. The Royal Society of Chemistry 2005.
Non-heme iron(III) complex with tridentate ligand: Synthesis, structures and catalytic oxidations of alkanes
Tyagi, Nidhi,Singh, Ovender,Ghosh, Kaushik
, p. 83 - 87 (2017)
We report synthesis and characterization of a mononuclear iron(III) complex [Fe(LH2)Cl2]+, 1 having tridentate ligand LH2 and their application in oxidation of alkanes. Complex, 1 was characterized by various analytical, spectroscopic, electrochemical, crystallographic and theoretical studies. The molecular structure determination showed the presence of distorted square pyramidal FeN3Cl2 coordination sphere. Selective oxidation of benzyl alcohol, fluorene, adamantane, 1-phenyl ethanol and n-octane in presence of catalytic amount [FeIII(LH2)Cl2]+ with H2O2 under mild conditions give products in good to excellent yields through FeIV[dbnd]O intermediate. Several studies were done to support the reactive intermediate. Generation of FeIV[dbnd]O intermediate was also supported by UV–visible titration of [FeIII(LH2)Cl2]+ and H2O2 at low temperature and their visual colour change from red (500 nm, ? = 1050 M? 1 cm? 1) to green (770 nm, ? = 153 M? 1 cm? 1).
One-pot diastereoselective synthesis of new racemic and achiral spirohydantoins
Mahmoodi, Nosrat O.,Khodaee, Ziba
, p. 304 - 306 (2004)
An efficient and versatile method was used for the diastereoselective synthesis of achiral and racemic spirohydantoins based on ketones 4, 5, 7 and 10.
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Baker,Adkins
, p. 3305,3306 (1940)
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Warren
, p. 2561,2563 (1961)
Structural basis for the properties of two single-site proline mutants of CYP102A1 (P450BM3)
Whitehouse, Christopher J. C.,Yang, Wen,Yorke, Jake A.,Rowlatt, Benjamin C.,Strong, Anthony J. F.,Blanford, Christopher F.,Bell, Stephen G.,Bartlam, Mark,Wong, Luet-Lok,Rao, Zihe
, p. 2549 - 2556 (2010)
The crystal structures of the haem domains of Ala330Pro and Ile401Pro, two single-site proline variants of CYP102A1 (P450BM3) from Bacillus megaterium, have been solved. In the A330P structure, the active site is constricted by the relocation of the Pro329 side chain into the substrate access channel, providing a basis for the distinctive C-H bond oxidation profiles given by the variant and the enhanced activity with small molecules. I401P, which is exceptionally active towards non-natural substrates, displays a number of structural similarities to substrate-bound forms of the wild-type enzyme, notably an off-axial water ligand, a drop in the proximal loop, and the positioning of two I-helix residues, Gly265 and His266, the reorientation of which prevents the formation of several intrahelical hydrogen bonds. Second-generation I401P variants gave high in vitro oxidation rates with non-natural substrates as varied as fluorene and propane, towards which the wild-type enzyme is essentially inactive. The substrate-free I401P haem domain had a reduction potential slightly more oxidising than the palmitate-bound wild-type haem domain, and a first electron transfer rate that was about 10 % faster. The electronic properties of A330P were, by contrast, similar to those of the substrate-free wild-type enzyme. Protein evolution with proline: The crystal structures of two contrasting single-site proline mutants of CYP102A1 (P450BM3) have been solved. The two mutations combine to give a variant that shows substantially enhanced catalytic activity with small non-natural substrates (see graph).
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Friedrich,E.C.,Taggart,D.B.
, p. 805 - 808 (1978)
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ENHANCEMENT OF Si-H BOND REACTIVITY IN PENTACOORDINATED STRUCTURES
Boyer, J.,Breliere, C.,Corriu, R. J. P.,Kpoton, A.,Poirier, M.,Royo, G.
, p. C39 - C43 (1986)
The reactions of pentacoordinated silicon dihydrides with alcohols, carboxylic acids and carbonyl compounds have been studied.The dihydrides are markedly more reactive than the corresponding tetracoordinated species.
Davies,Hodge
, p. 3158,3163,3164 (1971)
Hyper-Acyloin Condensation, from Simple Aromatic Esters to Phenanthrenequinones: A New Reaction of C8K
Tamarkin, Dov,Rabinovitz, Mordecai
, p. 3472 - 3474 (1987)
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The fluorenyl cation
Costa, Paolo,Trosien, Iris,Fernandez-Oliva, Miguel,Sanchez-Garcia, Elsa,Sander, Wolfram
, p. 2656 - 2660 (2015)
The fluorenyl cation is a textbook example for a 4πantiaromatic cation. However, contrasting results have been published on how the annelated benzene rings compensate the destabilizing effect of the 4π antiaromatic five-membered ring in its core. Whereas previous attempts to synthesize this cation in superacidic media resulted in undefined polymeric material only, we herein report that it can be generated and isolated in amorphous water ice at temperatures below 30 K by photolysis of diazofluorene. Under these conditions, the fluorenylidene is protonated by water to give the fluorenyl cation, which could be characterized spectroscopically. Its absorption in the visible-light range matches that previously obtained by ultrafast absorption spectroscopy, and furthermore, its IR spectrum could be recorded. The IR bands in amorphous ice very nicely match predictions from DFT and DFT/MM calculations, suggesting the absence of strong interactions between the cation and surrounding water molecules.
Reagents and methods for esterification
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Page/Page column 22-24, (2020/03/18)
A method for esterification of one or more carboxylic acid groups in a compound containing one or more carboxylic acid groups wherein the esterification reagent is a diazo-compound of formula: wherein the R1 and R2 groups of the diazo compound are selected such that the corresponding organic compound of formula: exhibits a —C—H pKa value between 18 and 29 as measured in DMSO. Specific reagents and methods for esterification are provided. The esterification reagents provided exhibit high selectivity for esterification of carboxylic acid groups over reaction with amine, alcohol or thiol groups in the compound containing one or more carboxylic acid groups. The method can be used to selectively esterify carboxylic acid groups in peptides or proteins.
1-D manganese(ii)-terpyridine coordination polymers as precatalysts for hydrofunctionalisation of carbonyl compounds
Johnson, Jahvon,Li, Sihan,Mo, Zixuan,Neary, Michelle C.,Zeng, Haisu,Zhang, Guoqi,Zheng, Shengping
supporting information, p. 2610 - 2615 (2020/03/05)
Reductive catalysis with earth-abundant metals is currently of increasing importance and shows potential in replacing precious metal catalysis. In this work, we revealed catalytic hydroboration and hydrosilylation of ketones and aldehydes achieved by a structurally defined manganese(ii) coordination polymer (CP) as a precatalyst under mild conditions. The manganese-catalysed methodology can be applied to a range of functionalized aldehydes and ketones with turnover numbers (TON) of up to 990. Preliminary results on the regioselective catalytic hydrofunctionalization of styrenes by the Mn-CP catalyst are also presented.
