Chemistry substitutional

Hydrazine and its alkylated derivatives are used as rocket fuels in organic chemistry, substituted phenylhydrazines are important in the characterisation of sugars and other compounds, for example aldehydes and ketones containing the carbonyl group C=0. 

Additional reductions in the amount of hazardous filter cake sludge produced were achieved with three process chemistry substitutions completed in September 1988, which eliminated a major source of chrome-containing wastes in the metal plating production facility. The initial substitutions replaced a chromic acid / nitric... 

Characteristics of some psychoactive phenylisopropylamin.es as listed in Burger s Medicinal Chemistry. Substitution of various molecules and molecular groups at various positions in the skeleton nucleus has been extensively tested and results in wide variations in potency (DOB is the strongest, exhibiting some 400 times the strength of mescaline). Those in the middle are the most popular in this series, but the recently-synthesized Aleph compounds, which contain sulfur and emphasize introspection, have also been well received. 

This type of reactions are very common in organic chemistry (substitution reaction). For example the chlorination of methane may give mono, di, tri and/or tetra halogen derivative. 

Chapter 10 Policies Promoting Green Chemistry Substitution Efforts... 

In view of the difficulties associated with pterin chemistry, substituted quinoxalines (9) have served as the initial synthetic models for molybdopterin (1). Garner, Joule, and co-workers (50-53) have pre-... 

Can the solvated/trapped/encapsulated electron be used for molecular electronics and quantum computing It is the tiniest capacitor known in chemistry and the electron degrees of freedom are largely decoupled from the nuclear ones. Can the solvated electron be the organic chemistry substitute for quantum dots ... 

Special Topic 7-1 Green Chemistry—Substitutes for Chlorofluorocarbons describes substitutes for chlorofluorocarbons, and Special Topic 7.2 Other Ozone-Depleting Chemicals describes other ozone-depleting chemicals. 

CYCLOHEXANE OXIDATION CAN GIF CHEMISTRY SUBSTITUTE FOR THE CLASSICAL PROCESS ... 

In furan chemistry, substitution reactions, such as alkylation, halogenation, sulphonation and nitration, occur regioselectively at C2 and/or C5 when these positions are not substituted, suggesting that la is the dominant resonance structure. Compared with its classical homologues 2 and 3, furan displays the lowest aromatic and the highest dienic character, as illustrated in Scheme 6.1 which also gives the two limiting structures of benzene and cyclopentadiene, respectively. 

Catalytic nucleophilic substitution reactions comprise some of the most commonly used catalytic processes in S)mthetic organic chemistry. Substitutions at aromatic and vinylic halides and sulfonates, sho vn generically in Equation 19.1, are commonplace in the preparation of pharmaceutical candidates, have often been used in the s)mtheses of natural products, and have been used many times in the syntheses of sophisticated conjugated organic materials. These metal-catalyzed reactions are typically called cross-coupling reactions. ... 

Process chemistry substitution using palladium-based and/or graphite-based alternatives. 

Armspach D, Constable E C, Diederich F, Housecraft C E and Nierengarten J-F 1996 Bucky-ligands fullerene-substituted oligopyridines for metallosupramolecular chemistry J. Chem. Soc., Chem. Commun. 2009-10... 

Claverie P, J P Daudey, J Lmglet, B Pullman, D Piazzola and M J Huron 1978. Studies of Solvent Effects. I. Discrete, Continuum and Discrete-Continuum Models and Their Comparison for Some Simple Cases NH, CH3OH and substituted NH4. Journal of Physical Chemistry 82 405-418. 

It is widely used in experimental chemistry, most commonly in statistical treatment of experimental uneertainty (Young, 1962). For eonvenienee, it is eommon to make the substitution... 

Organic chemistry demands much from chlorine, both as an oxidizing agent and in substitution, since it often brings many desired properties in an organic compound when substituted for hydrogen, as in one form of synthetic rubber. 

Whereas most chemists focused their attention on speculation about atoms and the question of atomic weights, the constant multiplicity in compounds occupied an increasingly central role. The new concept of substitution, i.e., the replacement of one element by another in a compound, started to make a major impact on chemistry in the 1840s. It was probably Dumas, who in the 1830s at the request of his father-in-law (who was the director of the famous Royal Sevres porcelain factory) resolved an event that upset a royal dinner party at the Tuil-... 

These studies at the same time aroused my interest in the mechanistic aspects of the reaetions, including the complexes of RCOF and RF with BF3 (and eventually with other Lewis acid fluorides) as well as the complexes they formed with aromatics. 1 isolated for the first time at low temperatures arenium tetrafluoroborates (the elusive (T-complexes of aromatic substitutions), although I had no means to pursue their structural study. Thus my long fascination with the chemistry of car-bocationic complexes began. 

Nitration is important for two reasons firstly, because it is the most general process for the preparation of aromatic nitro compounds secondly, because of the part which it has played in the development of theoretical organic chemistry. It is of interest because of its own characteristics as an electrophilic substitution. 

The development of theoretical organic chemistry was intimately entwined with the development of that particular aspect of it concerned with aromatic substitution the history of this twin growth has been authoritatively traced. Only the main developments, particularly as they affect nitration, will be noted here. 

For the electronic theory of organic chemistry 1926 was the annus mirabilis, and, particularly, as they applied to aromatic substitution, the... 

Substituted aroyl- and heteroaroyltrimethylsilanes (acylsilanes) are prepared by the coupling of an aroyl chloride with (Me3Si)2 without decarbonylation, and this chemistry is treated in Section 1.2[629], Under certain conditions, aroyl chlorides react with disilanes after decarbonylation. Thus the reaction of aroyl chlorides with disilane via decarbonylation is a good preparative method for aromatic silicon compounds. As an interesting application, trimel-litic anhydride chloride (764) reacts with dichlorotetramethyidisilane to afford 4-chlorodimethylsilylphthalic anhydride (765), which is converted into 766 and used for polymerization[630]. When the reaction is carried out in a non-polar solvent, biphthalic anhydride (767) is formed[631]. Benzylchlorodimethylsilane (768) is obtained by the coupling of benzyl chloride with dichlorotetramethyl-disilane[632,633]. 

Substitutive names are preferred but functional class names are sometimes more convenient or more familiar and are frequently encountered m organic chemistry... 

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