ChemInform Abstract: Pyridinium Ylides in Organic Synthesis. Part 1. General Aspects: Formation Methods, Structure, and Physicochemical Properties

ChemInform ◽  
2010 ◽  
Vol 25 (46) ◽  
pp. no-no
Author(s):  
V. P. LITVINOV
Keyword(s):  
Physicochemical Properties ◽  
Organic Synthesis ◽  
Pyridinium Ylides ◽  
General Aspects

Isoxazol-5-ones as Strategic Building Blocks in Organic Synthesis

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2473-2489 ◽  
Author(s):  
Amanda da Silva ◽  
Alessandra Fernandes ◽  
Samuel Thurow ◽  
Mateus Stivanin ◽  
Igor Jurberg
Keyword(s):  
Natural Products ◽  
Biological Activity ◽  
Organic Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Short Review ◽  
Preparation Methods ◽  
Drug Candidates ◽  
General Aspects

Isoxazol-5-one rings have been identified as relevant motifs in drug candidates, agrochemicals, and materials. Furthermore, this heterocycle has been also applied as a versatile building block for the preparation of a variety of densely functionalized molecules. This short review will present the most representative applications of isoxazol-5-ones in organic synthesis while discussing their properties and reactivity.1 Introduction1.1 General Aspects1.1.1 Tautomerism1.1.2 Importance: Natural Products Isolation, Biological Activity, and Materials1.1.3 Preparation Methods2 Isoxazol-5-ones in Organic Synthesis2.1 General Reactivity2.2 Specific Examples2.2.1 Alkylation Strategies2.2.2 Alkyne Synthesis2.2.3 Annulation Reactions2.2.4 N–O Bond Insertions2.2.4.1 Preparation of 1,3-Oxazin-6-ones3 Conclusions

scholarly journals BIODIESEL - GENERAL ASPECTS

2005 ◽  
Vol 03 (2) ◽  
pp. 7-12
Author(s):  
Renata C. BOCCARDO
Keyword(s):  
Carbon Monoxide ◽  
Carbon Cycle ◽  
Physicochemical Properties ◽  
Alternative Fuel ◽  
Diesel Oil ◽  
General Aspects

Faced with the need to use alternative fuel sources, due to the growing scarcity of oil, biodiesel comes to contribute with its excellent qualities in view of being a biodegradable, renewable product that obeys the carbon cycle. Biodiesel has physicochemical properties very similar to diesel oil and, therefore, does not need a new engine for its operation. Biodiesel, when added to diesel oil, improves its lubricity, dispensing with more polluting additives. Because it contains oxygen in its chemical chain, it has better burning with a consequent decrease in carbon monoxide and hydrocarbons.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Applications of CCEM to Environmental Health Problems

1985 ◽  
Vol 43 ◽  
pp. 102-103
Author(s):  
R. J. Lee ◽  
J. S. Walker
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Environmental Health ◽  
Computer Control ◽  
External Agent ◽  
External Agents ◽  
Computer Controlled ◽  
Primitive State ◽  
Textural Changes ◽  
General Aspects

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

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