Substitution reactions summary table

A summary of the in situ use of the azobenzene probases is given in Table 2. Apart from the generation of ylid, referred to above, the main applications have been for N- and C-alkylation of weak nitrogen and carbon acids, for the promotion of condensation and substitution reactions involving carbanions such as the cyano-methyl anion, for an interesting carboxylation reaction (entries 4 and 17), and for base-promoted cyclisations (entries 5 and 6). 

Table 5—Summary of Electrophilic Substitution Reactions of Phenol, Diphenyl Ether, and Anisole... 

The free radical substitution reactions, other than phenylation, of pyridine and its derivatives have received but scant attention. Alkylation of pyridine itself has been studied briefly, the alkyl radicals being generated either by the thermolysis of diacyl peroxides or of lead tetraacetate in acetic acid, or by electrolysis of the carboxylic acid precursor (for summary, see Norman and Radda369). Most of the available results are summarized in Table XIV. These figures on isomer ratios are not very reliable since the analyses were carried out by... 

Table 10.2 Summary of Substitution Reactions—cont d Reaction...

Table 10.6 Summary of the Reactivity of Alkyl Halides Substitution Reactions in Nucleophilic...

In summary, all the early kinetic and spectroscopic evidence support the contention that the nltronlum Ion Is the effective electrophilic agent. Moreover, the rate data for the nitration reaction presented in Table I and illustrated In Figure 1 are representative of the normal reactivity pattern observed for many other electrophilic substitution reactions as shown by the results displayed in Figures 2 and 3. 

The stereochemistry of nucleophilic substitution reactions has been examined for substrates ranging in complexity from primary alkyl to triarylmethyl. A summary of representative examples is presented in Table 5.12. Chiral 1-butanol-l-rf and its derivatives have small, but measurable, optical rotations and provide useful substrates for the important case of substitution in primary systems. Entry 1 in Table 5.12 illustrates the stereospecific inversion observed in 1-butyl-1-rf... 

Now that we have considered the many factors involved in substitution reactions, we present an overview useful to predict the type of mechanism that dominates under certain reaction conditions (Table 9.9). Examples of how to use this summary are given in Section 9.4. 

Table 22.5 Summary of the Nucleophilic Substitution Reactions of Carboxylic Acids and Their Derivatives...

PFD (process flow diagram), 972 process description, 970-971 reaction kinetics, 971. 978 references, 970. 978 simulation (CHEMCAD), 978 stream tables, 973-975 utility summary table, 975 Substitution approach, 875 Sum of the years digits depreciation accelerated depreciation, 285 compared to other methods, 282-283. 284. 289 definition, 282 formula for, 282... 

In Summary Increased reactivity goes hand in hand with reduced selectivity in radical substitution reactions. Huorine and chlorine, the more reactive halogens, discriminate between the various types of C-H bonds much less than does the less reactive bromine (Table 3-6). 

Section 12 1 On reaction with electrophilic reagents compounds that contain a ben zene ring undergo electrophilic aromatic substitution Table 12 1 m Section 12 1 and Table 12 3 m this summary give examples... 

Because many of the alternates and replacements for CFCs have an abstractable hydrogen atom, reaction with OH in the troposphere dominates their loss. Table 13.4 gives some rate constants for the reaction of OH with these compounds the kinetics summary of De-More et al. (1997) should be consulted for other compounds. It is seen that the rate constants at 298 K are typically in the range of 10-l3-10-ls cm3 molecule-1 s-1, depending on the degree of halogen substitution and the nature of the halogen, e.g., F, Cl, or Br. Typical A factors are of the order of 1 X 10 12 cm3 molecule-1 s-1 per H atom (DeMore, 1996). 

A summary of the major chemical reactions of free radicals is given in Table 4.3. Broadly speaking these can be classified as unimolecular reactions of dissociations and isomerizations, and bimolecular reactions of additions, disproportionations, substitutions, etc. The complexity of many photochemical reactions stems in fact from these free radical reactions, for a single species formed in a simple primary process can lead to a variety of final products. 

This chapter has provided a summary of the reactions that naphthyridines can undergo with KNH2/NH3. The complex behavior of these naphthyridines toward this reagent (ipso, tele, and cine substitutions, as well as ring transformations) is shown in the Table VIII. 

A summary of results from experiments exploring the scope of catalytic AD is presented in Tables 6D.2-6D.6. The results are divided according to the five substitution patterns for which useful levels of enantioselectivity have thus far been achieved so that the synthetic chemist can easily compare a potential candidate for AD with the existing precedent. Our emphasis in this chapter is on the best conditions currently available for a general catalytic AD process, because this is very likely of the most practical interest to the reader. However, Tables 6D.2-6D.6 include most of the published data from the Sharpless laboratory for AD under a variety of conditions. These data are included to permit the reader to place in context results reported in several publications and to illustrate the variety of olefins that have been used at least once for an AD reaction. Additional applications of catalytic AD reported in the literature are integrated into the discussions of the different olefin categories. Examples illustrating double diastereoselectivity" are collected and discussed in a separate section. 

Table XXIV provides a summary of the p values for the electrophilic substitutions of thiophene derivatives when available, the p values for the corresponding reactions of benzene derivatives are also recorded for comparison.

Figure 2 Plots of the logarithm of electron transfer rate vs. the negative of the free energy of the reaction for three ET models and six rate measurements. The data are from Refs. 54, 55, 57, 59, 60 for a Zn-substituted Candida krusei cytochrome c that was also successively substituted at histidine 33 by three Ru(NH3)4L(His 33)3+ derivatives with L = NH3, pyridine, or isonicotinamide. The shortest direct distance between the porphyrin and imidazole carbon atoms was 13 A corresponding to the 10-A edge-to-edge D/A distance. Table 1 presents a summary of the parameters used in the three calculations plotted in this figure. For a (3 of 1.2 A-1, Eq. (5) yields HAB values ( 10 cm-1) of 80 cm-1,50 cm-1, and 75 cm-1, respectively, for Eq. (1), the semiclassical model [Eq. (4)], and the Miller-Closs model at the above D/A separation distance. The s values were calculated using Eq. (6) with the following parameters aD = 10 A, aA = 6 A, and r = 13 A. The kj and H°B parameters were varied independently to produce the plotted curves.

A summary of metathesis reactions in ionic liquids is presented in Table 7.1. From the data available it appears that these reactions can easily be performed in neat ionic liquids and increased reaction rates are sometimes observed relative to molecular solvents. Co-solvents are used in some cases, mainly to obtain a biphasic system and thereby facilitate product isolation. So far, only imidazolium-type solvents have been employed with variations in the alkyl substitution pattern and the nature of the anion. Apart from the common perfluorinated anions, chloroaluminates have also been used,... 

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