نتایج جستجو برای: state thermolysis

تعداد نتایج: 857909  

2013
Curt Wentrup Ales Reisinger David Kvaskoff

Both flash vacuum thermolysis (FVT) and matrix photolysis generate 2-diazomethylpyrazine (22) from 1,2,3-triazolo[1,5-a]pyrazine (24). FVT of 4-azidopyridine (18) as well as of 24 or 2-(5-tetrazolyl)pyrazine (23) affords the products expected from the nitrene, i.e., 4,4'-azopyridine and 2- and 3-cyanopyrroles. Matrix photolyses of both 18 and 24 result in ring expansion of 4-pyridylnitrene/2-py...

2007
C. KRAUSS C. BUBENZER H. SCHEER

From the A-dihydrobilindione 3. the pyridinium derivatives 6a,b and analogues therwf have been obtained by a formal nucleophilic substitution. The reaction is rationalized as a photochemically assisted oxidation of 3 with a subsequent regioselective addition of pyridine at C-5. By thermolysis. 6a.b yields back the parent bilin 3, together with an oxidation product. The significance of the react...

2012
S A Sherif F Barbir T N Veziroglu

This paper presents an overview of the principles of hydrogen energy production, storage, and util ization. Hydrogen production wil l cover a whole array of methods including electrolysis, thermolysis, photolysis, thermochemical cycles, and production from biomass. H ydrogen storage will cover al l modes of gaseous, liquid, slush, and metal hydride storage. Hydrogen uti l ization will focus on ...

Journal: :Chemical communications 2014
Vitaly Nesterov Zheng-Wang Qu Gregor Schnakenburg Stefan Grimme Rainer Streubel

Open-shell phosphanyl complexes (OC)5W{(Me3Si)2HCP(X)} (X = F, H), obtained by one-electron oxidation of lithium phosphanido complexes, were trapped by TEMPO to yield novel thermally labile P-nitroxyl phosphane complexes. First experimental evidence for an open-shell P-F phosphanoxyl complex (OC)5W{(Me3Si)2HCP(O)F}, formed upon thermolysis of corresponding P-nitroxyl derivative, is reported; re...

Journal: :The Journal of organic chemistry 2002
Majed Shtaiwi Curt Wentrup

Iminopropadienones, RN=C=C=C=O, can be generated from four different types of precursors in flash vacuum thermolysis reactions: 1,3-dioxane-4,6-diones 1, isoxazolopyrimidinones 2, pyridopyrimidinium olates 3, and pyridopyrimidinones 4. 2,6-Difluorophenyl-, 2,6-diethylphenyl-, o-tert-butylphenyl-, and mesityliminopropadienone have been directly observed by Ar matrix IR spectroscopy in one or mor...

Journal: :Organic letters 2011
Vincent Tran Thomas G Minehan

Mild thermolysis of tert-butyl alkynyl ethers furnishes aldoketenes, which undergo facile [2 + 2] cycloaddition reactions with pendant di- and trisubstituted alkenes. A wide variety of cis-fused cyclobutanones are produced in moderate to high diastereoselectivity and good to excellent yields by this method, and free hydroxyl groups are tolerated in the ene-ynol ether starting materials. Enol-yn...

Journal: :Chemical communications 2013
Kamal Nayan Sharma Hemant Joshi Alpesh K Sharma Om Prakash Ajai K Singh

The PdTe NPs (hexagonal) and nanorods (first example) have been synthesized for the first time from single source precursors (SSPs), [Pd(L1)Cl2] (1) and [Pd(L2)Cl]BF4 (2) [L1, 4-bromo-1-[2-(4-methoxyphenyltellanyl)ethyl]-1H-pyrazole; L2, bis-[2-(4-bromopyrazol-1-yl)ethyl]telluride], by their thermolysis in an OA–ODE mixture (1:1) and TOP respectively. The composition of the PdTe phase does not ...

Journal: :The Journal of organic chemistry 2010
Michael E Jung Ting-Hu Zhang Rebecca M Lui Osvaldo Gutierrez K N Houk

While thermolysis of the macrobicyclic triene lactone 12 did not produce the expected bicyclic transannular Diels-Alder (BTADA) product 13, heating the corresponding ether 18 to 110 °C for 4 h afforded a quantitative yield of the desired cycloadduct 19, which could be easily reduced to the perhydrophenanthrene, an ABC ring analogue of fusidic acid 1. Theoretical calculations with hybrid density...

Journal: :Journal of the American Society for Mass Spectrometry 2008

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