Alkyl group table

Table 111-103 2-Alkylthiazoles with one function on the alkyl group Table 111-104 4-Alkylthiazoles with one function on the alkyl group Table I1I-105 5-Alkylthiazoles with one function on the alkyl group...

A large number of papers has been devoted to the influence of substituents upon the reactivity of benzene nucleus. Extensive studies concerning various benzene derivatives and catalysts from the platinum group metals have been published by H. A. Smith and his co-workers (for a summary see 36). The most consistent sets of data on alkylbenzenes are available from him and other groups of authors. Table VI summarizes the influence of the structure of a single alkyl group Table VII (94, 95, 97-103) summarizes the influence of the number and position of the methyl groups. Both series show very similar behavior on all metal catalysts, a decrease in rate with the size... 

The decrease in hydrogenation rate with increasing size of the alkyl group (Table VI) (93-96) can be correlated by the Taft equation. However, the correlation of the data by Smith and Pennekamp (93) (series 70) using the polar parameter Taft equation is applied that also includes steric constants. Similarly, Kieboom (34) has discussed Yoshida s correlation of series 73 based on main conclusion has been that the data do not allow a clear distinction between steric and polar effects. It seems that both operate in the same direction. Series 72 and 73, in which the rate data have been separated into the rate constants and adsorption coefficients, show opposite trends with the latter parameter. A similar problem has been encountered by Volter, Hermann, and Heise (100) and by Najemnik and Zdrazil (103) in the series of methylbenzenes (Table VII) and is discussed in this connection. 

Carbon-13 shifts of cyano groups in nitriles are found between 110 und 125 ppm (Table 4.46) [77 a, 352]. Shift values close to 125 ppm are characteristic of nitriles with a branched alkyl groups (Table 4.46). Similiar to the isoelectronic ethynyl group, the nitrile function shields the oc carbon owing to the anisotropy effect. Alkenyl carbon shifts of... 

An isolated carbon-carbon triple bond similarly absorbs in the 180nm region (acetylene, Am, 173 nm, e as 6000) the absorption maximum is shifted to longer wavelengths by the presence of alkyl groups (Table 3.6). 

Fig. 3a, b. Plot of hydrogen bond donating parameter (a) with electric field (F) (Volt/nm), shown by o, and scaled potential (kcal/mol), shown by A a for molecules containing OH group (Table 1) b for molecules containing alkyl groups (Table 2)... 

Silyl groups, which tend to increase lipid solubility, may be used as a substitute for alkyl branching in space-filling groups. Direct substitution of a silicon atom for a carbon atom increases the hydrophobic character of a compound, even without the addition of more alkyl groups. Table III lists the relative partition coefficients of two pairs of carbon and silicon compounds in octanol-water, a system used to approximate the lipid-water system within an organism. As may be seen from the table, the silicon compounds are two to five times more soluble in the octanol phase this effect falls off with an increasing number of carbon atoms in the parent structure (36). 

If the alkyl substituent is in position 3, the 2-position is the most favored from the electronic point of view, being ortho to the alkyl group and alpha to the heteroatom. The other a position (5) is, however, free from steric effects. Consequently, reactions of 3-alkyl thiophenes, -furans, and -pyrroles yield a mixture of 2- and 5-substituted isomers, the composition of which depends on the nature of the heteroatom, the electrophile, and the size of the alkyl group. Table XXI reports the isomer distribution in the acylation of 3-methyl-, 3-isopropyl-, and 3-i-butylthiophenes and shows the importance of the steric factor in determining the orientation. 

Name and number each atom or group attached to the parent compound. The number tells you the position of the group on the main chain, and the name tells you what t)rpe of substituent is present at that position. For example, it may be one of the halogens [F-(fluoro), Cl-(chloro), Br-(bromo), and I-(iodo)] or an alkyl group (Tables 11.4 and 11.5). In the following examples the parent chain is highlighted in yellow ... 

Ethers have the general formula R—O — R where R and R stand for alkyl groups (Table 12.6), which may be the same or different. Methyl-t iary-butyl ether (MTBE) was once an important commercial ether because of its use in oxygenated and reformulated gasolines. 

Cellulose ethers are alky modifications wherein part of the hydrogen atoms of the three hydroxyl groups on the anhydroglucose repeating unit are replaced by methyl, hydroxyethyl, hydroxypropyl, carboxymethyl (glycolate) or mixed alkyl groups (Table 1). 

The P chemical shi of acyclic phosphites depend little on the steric bulk of the alkyl group (Table V). On the other hand, the bicyclic phosphite 5 with one five-membeied ring ( = -P105 ppm) is shifted downfield by 13.5... 

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