1567-89-1Relevant articles and documents
STRUCTURE AND STEREOCHEMISTRY OF GALBANIC ACID
Bagirov, V. Yu.,Scheichenko, V. I.,Veselovskaya, N. V.,Sklyar, Yu. E.,Savina, A. A.,Kir'yanova, I. A.
, p. 439 - 441 (1980)
On the basis of the 1H NMR spectrum at 300 MHz and the results of chemical degradation, the structure of 7-coumarin has been proposed for galbanic acid.
Ru(III) catalysed oxidation of 2-propanol by Cr(VI) in micellar media
Chowdhury,Rakshit,Acharjee, Animesh,Ghosh, Aniruddha,Mahali, Kalachand,Saha, Bidyut
, (2019)
Acetone, the simplest ketone of abundant useful is produced from 2-propanol by oxidation with hexavalent Cr(VI) sluggishly under pseudo 1st order reaction condition. The rate is enhanced considerably using Ru(III) metal salt solution at ppm level as a cat
Is the tungsten(IV) complex (NEt4)2[WO(mnt)2] a functional analogue of acetylene hydratase?
Schreyer, Matthias,Hintermann, Lukas
, p. 2332 - 2339 (2017)
The tungsten(IV) complex (Et4N)2[W(O)(mnt)2] (1; mnt = maleonitriledithiolate) was proposed (Sarkar et al., J. Am. Chem. Soc. 1997, 119, 4315) to be a functional analogue of the active center of the enzyme acetylene hydratase from Pelobacter acetylenicus, which hydrates acetylene (ethyne; 2) to acetaldehyde (ethanal; 3). In the absence of a satisfactory mechanistic proposal for the hydration reaction, we considered the possibility of a metal-vinylidene type activation mode, as it is well established for rutheniumbased alkyne hydration catalysts with anti-Markovnikov regioselectivity. To validate the hypothesis, the regioselectivity of tungsten- catalyzed alkyne hydration of a terminal, higher alkyne had to be determined. However, complex 1 was not a competent catalyst for the hydration of 1-octyne under the conditions tested. Furthermore, we could not observe the earlier reported hydration activity of complex 1 towards acetylene. A critical assessment of, and a possible explanation for the earlier reported results are offered. The title question is answered with "no".
A re-examination of supra-molecular aggregation in two polymorphs of acetone 2,4-dinitro-phenyl-hydrazone
Wardell, James L.,Howie, R. Alan,Low, John N.,Glidewell, Christopher
, p. o231-o233 (2007)
The structure of the triclinic polymorph of acetone 2,4- dinitrophenylhydrazone, C9H10N4O4, has been redetermined from diffraction data collected at 120 (2) K; the mol-ecules are linked by C - H...O hydrogen bonds into centrosymmetric R 2 2(10)
Aerobic oxidation of formaldehyde catalyzed by polyvanadotungstates
Guo, Weiwei,Luo, Zhen,Lv, Hongjin,Hill, Craig L.
, p. 1154 - 1161 (2014)
Three tetra-n-butylammonium (TBA) salts of polyvanadotungstates, [n-Bu 4N]6[PW9V3O40] (PW 9V3), [n-Bu4N]5H2PW 8V4O40 (PW8V4), and [n-Bu4N]4H5PW6V6O 40·20H2O (PW6V6), have been synthesized and shown to be effective catalysts for the aerobic oxidation of formaldehyde to formic acid under ambient conditions. These complexes, characterized by elemental analysis, Fourier transform infrared spectroscopy, UV-vis spectroscopy, and thermogravimetric analysis, exhibit a catalytic activity for this reaction comparable to those of other polyoxometalates. Importantly, they are more effective in the presence of water than the metal oxide-supported Pt and/or Au nanoparticles traditionally used as catalysts for formaldehyde oxidation in the gas phase. The polyvanadotungstate-catalyzed oxidation reactions are first-order in formaldehyde, parabolic-order (slow, fast, and slow again) in catalyst, and zero-order in O2. Under optimized conditions, a turnover number of ～57 has been obtained. These catalysts can be recycled and reused without a significant loss of catalytic activity.
Iron-Catalyzed Reductive Amination of Aldehydes in Isopropyl Alcohol/Water Media as Hydrogen Sources
Petricci, Elena,Santillo, Niccolò,Castagnolo, Daniele,Cini, Elena,Taddei, Maurizio
supporting information, p. 2560 - 2565 (2018/07/29)
Reductive amination can be carried in i-PrOH/H2O as hydrogen sources using commercially available iron carbonyl complexes. Within an aqueous alkaline environment, a hydridocarboferrate is formed and its reducing potential is exploited for hydrogenation of the imine (or iminium ion) obtained in situ from aldehydes or ketones, and primary or secondary amines in almost equimolar ratio. This completely sustainable and hydrogen-free process proceeds at 100 °C using Fe3(CO)12 as catalyst precursor under convectional heating while Fe2(CO)9 gave better results when the reaction was carried out under MW dielectric heating. Both enolizable and non-enolizable aldehydes may be successfully employed in reactions with aliphatic and aromatic amines. (Figure presented.).
Burgess Reagent Facilitated Alcohol Oxidations in DMSO
Sultane, Prakash R.,Bielawski, Christopher W.
, p. 1046 - 1052 (2018/06/18)
The Burgess reagent ([methoxycarbonylsulfamoyl]triethylammonium hydroxide) has historically found utility as a dehydrating agent. Herein we show that, in the presence of dimethyl sulfoxide, the Burgess reagent efficiently and rapidly facilitates the oxidation of a broad range of primary and secondary alcohols to their corresponding aldehydes and ketones in excellent yields and under mild conditions, and can be combined with other transformations (e.g., Wittig olefinations). A mechanism similar to those described for the Pfitzner-Moffatt and Swern oxidations is proposed.
A unique annulation of 7-azaindoles with alkenyl esters to produce π-conjugated 7-azaindole derivatives
Li, Shuai-Shuai,Liu, Chen-Fei,Xia, Ying-Qi,Li, Wei-Huan,Zhang, Guo-Tai,Zhang, Xiao-Mei,Dong, Lin
supporting information, p. 5214 - 5218 (2016/07/06)
Rhodium(iii)-catalyzed N-directed ortho C-H activation and subsequent roll-over C-H activation represents an important strategy to synthesize fused polycyclic compounds. Herein, the novel methodology broadens the scope of the coupling partner to alkenes, which working smoothly with 7-azaindoles has been proven to be an efficient and atom-economical strategy to access complex π-conjugated 7-azaindole derivatives.
IMIDAZOLINE RECEPTOR TYPE 1 LIGANDS FOR USE AS THERAPEUTICS
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Page/Page column 265-266, (2016/07/27)
This disclosure provides compounds and compositions for use as analgesics and for the treatment of various conditions, such as pain, headaches, allodynia, and fibromyalgia. The disclosure also provides compounds that are ligands, and in some embodiments, modulators (e.g., agonists), for the imidazoline receptor type 1.
Cross-Dehydrogenative Coupling of Tertiary Amines and Terminal Alkynes Catalyzed by Copper Nanoparticles on Zeolite
Alonso, Francisco,Arroyo, Adrián,Martín-García, Iris,Moglie, Yanina
, p. 3549 - 3561 (2016/01/25)
A wide range of catalysts based on supported copper nanoparticles have been prepared and tested in the cross-dehydrogenative coupling of tertiary amines and terminal alkynes. Copper nanoparticles on zeolite Y were found to be the most effective catalyst in the presence of tert-butyl hydroperoxide as the oxidant. Contrary to the previously reported methodologies involving copper catalysts, reactions have been accomplished without the need of an inert atmosphere and in the absence of solvent, using 1.5mol% catalyst. A variety of tertiary amines, including aromatic, benzylic and aliphatic ones, have been coupled with both aromatic and aliphatic alkynes to furnish the corresponding propargylamines in moderate-to-excellent yields. The procedure has been successfully scaled-up to 12mmol with a high conversion (93%). Moreover, the catalyst has been reused in seven cycles maintaining a good performance. Its catalytic activity has been compared with that of an array of commercial copper catalysts, being superior as regards the conversion and minimizing the alkyne homocoupling as a side reaction. The negative filtration test points to a heterogeneous nature of the process. Based on compelling experimental evidence, a novel reaction mechanism has been delineated which outlines the essential role of free radicals and the couple copper(I)/copper(II).
