Addition reactions aromatic terminator

In many of these cases, the nucleophile is a C=C double bond (usually an alkenic group and less frequently an aromatic group). Alkenic oxime mesylates enable intramolecular cyclization by an electrophihc addition of the double bond to the electrophilic intermediate. These reactions are terminated by a proton loss. 

Aromatic primary and secondary amines behave generally like the phenols. However, the over-all process is more complex because an additional series of termination and transfer reactions is introduced by the rapid formation of nitroxides in the following reaction. 

The following compounds with H—C and II—M bonds undergo oxidative addition to form metal hydrides. This is examplified by the reaction of 6, which is often called ortho-metallation, and occurs on the aromatic C—H bond at the ortho position of such donar atoms as N, S, 0 and P. Reactions of terminal alkynes and aldehydes are known to start by the oxidative addition of their C—H bonds. Some reactions of carboxylic acids and active methylene compounds are explained as starting with oxidative addition of their O—H and C—H bonds. 

However, the use of basic anions is not the sole approach followed to obtaining basic ILs. Liquid salts bearing this additional property can be prepared also by incorporation of a basic center into the cation. This approach generally affords more thermally stable ILs than those based on basic anions, which frequently present relatively low decomposition temperatures. Basic ionic liquids bearing aliphatic or aromatic amines on the side chain(s) have been synthesized and, recently, some of these have been used as both the solvent and base for Heck, copper free Sonogashira, and for homocoupling reactions of terminal alkynes (Figure 4.2). 

Addition of the terminal oxygen of phenyl peroxy to the ortho position of the aromatic ring has a barrier that is only 2 - 3 kcal mol lower than the reverse reaction back to ohenvl radical plus O2. Because its transition state structure is tight,... 

HR-602 - This system represents a different resin chemistry through use of acetylene-terminated polyimide structure. The cure mechanism consists of an addition reaction with no release of volatiles during cure. The intermediate acetylene-terminated polyimide structure is shown below. Reaction to the final cured structure is proposed as a trimerization of the acetylene groups to form an aromatic structure. 

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