Abstracts special

Abstract Special theoretical tools are needed to carry out ab initio simulations of... 

The systematic lUPAC nomenclature of compounds tries to characterize compounds by a unique name. The names are quite often not as compact as the trivial names, which are short and simple to memorize. In fact, the lUPAC name can be quite long and cumbersome. This is one reason why trivial names are still heavily used today. The basic aim of the lUPAC nomenclature is to describe particular parts of the structure (fi agments) in a systematic manner, with special expressions from a vocabulary of terms. Therefore, the systematic nomenclature can be, and is, used in database systems such as the Chemical Abstracts Service (see Section 5.4) as index for chemical structures. However, this notation does not directly allow the extraction of additional information about the molecule, such as bond orders or molecular weight. 

Thiazolium derivatives unsubstituted at the 2-position (35) are potentially interesting precursors of A-4-thiazoline-2-thiones and A-4-thiazoline-2-ones. Compound 35 in basic medium undergoes proton abstraction leading to the very active nucleophilic species 36a and 36b (Scheme 16) (43-46). Special interest has been focused upon the reactivity of 36a and 36b because they are considered as the reactive species of the thiamine action in some biochemical reaction, and as catalysts for several condensation reactions (47-50). 

The Annual Proceedings of the Joiat Army-Navy-Air Force (JANNAF) Propulsion Meetings, the reports of the special committees, and the periodic hterature surveys pubHshed by the Chemical Propulsion Information Agency including the aimual Chemical Propulsion Abstracts are iuvaluable sources of information on all aspects of Hquid and soHd gun and rocket propellants. They maybe classified. 

Other Databases with Patent Information. The APIPAT database has been discussed, as have the unique capabihties of the merged WPI—APIPAT file on ORBIT. Many other databases contain substantial amounts of patent information, notable among them are Derwent s biotechnology Abstracts the TULSA database (petroleum exploration and production), several specialized pharmaceutical files, PAPERCHEM, and METADEX. A very complete listing of databases containing patent information circa 1990 has been prepared (38). 

Chemical Abstracts Ninth Collective Index, Index Guide, Appendix IV F. Specialized Substances, par. 215, pp. 2021—2051 (1972—1976). In the Tenth and Eleventh Collective Indexes, the corresponding page numbers are 1921—1951 and 1931—1971, respectively. 

A special issue (Volume 6) of the Bulletin de la Societd Chimique de France published in 1986 contained papers contributed to the Moissan symposium Abstracts of the papers presented at this symposium were published as a special volume (Volume 35) of the Journal of Fluorine Chemistry m 1987 A separate volume (Volume 54) of the Journal of Fluorine Chemistry was also issued m 1991 and contained abstracts of papers presented at the Thirteenth International Fluorine Symposium in Bochum, Germany... 

Ionic liquids may be viewed as a new and remarkable class of solvents, or as a type of materials that have a long and useful history. In fact, ionic liquids are both, depending on your point of view. It is absolutely clear though, that whatever ionic liquids are, there has been an explosion of interest in them. Entries in Chemical Abstracts for the term ionic liquids were steady at about twenty per year through 1995, but had grown to over 300 in 2001. The increased interest is clearly due to the realization that these materials, formerly used for specialized electrochemical applications, may have greater utility as reaction solvents. 

The main function of most lubricants is to reduce friction and wear between moving surfaces and to abstract heat. They also have to remove debris from the contact area, e.g. combustion products in an engine cylinder, swarf in metal-cutting operations. Sometimes they have to protect the lubricated or adjacent parts against corrosion, but this is not a prime function of most lubricants. On the other hand, many lubricants do contain corrosion inhibitors and some lubricating oils, greases, mineral fluids and compounds are specially formulated to prevent the corrosion of machinery or machine parts, particularly when these components are in storage or transit. These temporary protectives are described in Section 17.3. 

Except for several chapters in the comprehensive monograph on heterocyclic chemistry (84MI1) no special articles covering the recent past are available. This review is an attempt to discuss the literature up to Volume 117 (1992) covered by Chemical Abstracts together with some accessible papers published in 1993. Only isolable or spectroscopically identifiable thio-, seleno-, and teluropyrans without exocyclic double bonds (hetero-pyrones and heteropyranylidene derivatives) are considered. All benzo derivatives and their annulated heteroanalogs (spiroheteropyrans) are excluded. 

Many successful projects have shown that application information can be divided into the following four categories Terminology, Special Characteristics, Abstract Functions, and Graphics. Although these categories are the basis for the searchable application data base, each project requires a conceptual phase to define how to focus. 

Abstract Since its discovery the chromium-mediated benzannulation reaction has been developed into a unique and useful tool in organic synthesis. In this review, topical aspects of this reaction concerning its mechanism and the chemo-, regio- and stereoselectivity are summerised and discussed in detail. Special attention is paid to the asymmetric benzannulation reaction and, finally, the importance of this reaction as a key step in the total synthesis of natural products is outlined. 

An intramolecular mechanism of the rearrangement has been shown in the special ESR study (refs. 21, 22), conducted on the model radicals, generated by abstraction of a bromine atom from T2 " the rate constant K2, equal to (5.0 + 0.3) X 104 sec- at 22°C, has been also determined. In addition, fragmentation of radical... 

This database consists of specially commissioned abstracts covering methods (including instrumental details and conditions), assays, applications and techniques in selected areas. All abstracts are written by specialists and are NOT simply copies of the author abstracts. For further details, contact ... 

This index is divided into two parts. Part 1 gives the names of compounds as used in these volumes as well as general terms for classes of compounds, types of reactions, synthetic applications, special apparatus, and unfamiliar methods. The complete names of all specific compounds are given in normal order as written in the text (e.g., ethyl cyano-acetate appears under ethyl). Some entries are common names and others are systematic Chemical Abstracts names, whichever was used in the text. 

Several of the software tools used most frequently today include Beilstein Crossfire (information at www.mdli.com) and SciFinder from the Chemical Abstracts Service (www.cas.org/scifinder/) for structure-based reaction searches. Reagent availability information is often searched with MDL s ACD and CAS s SciFinder. Special compound collections and contract services offered by new companies such as ChemNavigator (www.chemnavigator.com)... 

Abstract In this review, recent developments of iron-catalyzed oxidations of olefins (epoxidation), alkanes, arenes, and alcohols are summarized. Special focus is given on the ligand systems and the catalytic performance of the iron complexes. In addition, the mechanistic involvement of high-valent iron-oxo species is discussed. 

Sufficiency. Given the example, the theory we employ to deduce the conditions must guarantee that the conditions on equivalence or dominance will be satisfied, since the example itself is simply an instance of the particular problem structure, and may not capture all the possible variations. The sufficient theory will thus end up being specialized by the example, but since we have asserted the need for validity of this process, it will still be guaranteed to satisfy the abstract necessary and sufficient conditions on dominance and equivalence. 

Shimoke, H., Komatsu, H. Matsui, I. (1987). Fluoride content in human enamel after removal of the applied glass ionomer cement. Journal of Dental Research, 66, Special Issue 131, Abstract No. 196. 

Watts, D. C., Combe, E. C. Greener, E. H. (1979). Effect of storage conditions on the mechanical properties of polyelectrolyte cements. Journal of Dental Research, 58, Special Issue C, Abstract No. 18. 

Babin, J. B., Hurst, R. V. V. Feary, T. (1978). Antibacterial activity of dental cements. Journal of Dental Research, 37, Special Issue B, Abstract No. 214. 

K. Nakatsu, Special Meeting of Kinki Chem. Soc., August, Osaka, Abstract No. 8, p. 17 (1988). 

---