Conjugation reactions, definition

While some conjugation reactions fail to totally meet the above criteria, they all satisfy at least one criterion. But what about the reactions of hydrolysis On the one hand, these fulfil none of the three above criteria, with the partial exception that the molecule (water) that reacts with the substrate is a polar one. On the other hand, the metabolic reactions of hydrolysis modify pre-existing functional groups of the substrates and, thus, meet the definition of functionalization reactions. 

Caldwell J. Conjugation reactions in foreign compound metabolism definition, consequences and species variations. Drug Metab Rev 1982 13 745. 

According to this scheme, definite amounts of inducer affected the secondary reaction and thus for qualitative characterization of conjugated reactions Shilov introduced an important parameter, representing the relationship between the amounts of acceptor and inducer participating in the reaction ... 

Thus, an interaction between reactions may be performed both with the help of stable IP (consecutive reactions), intermediate compounds (initiation, conjugated reactions, etc.), and in their absence (a definite type of parallel reactions). Of special interest for us are interrelated reactions performed with the help of labile, highly reactive intermediate compounds. This question will also be discussed below. 

Note also an important point when actor expenditure in conjugated reactions is so high, a large amount of it is used in the primary reaction, when active sites are formed. These sites are IP, and a definite part of them is spent in the formation of final products in the primary and secondary reactions. 

At the present time, detection of chemical induction in complex reactions is a little-developed area in the field of conjugated reactions. Usually, difficulties occur in the interpretation of the induced reaction mechanism and its kinetic description. In fact, textbooks on chemical kinetics [1 1] either have no methodological notes on these aspects or consider only a narrow, definite type of conjugated processes. 

In the literature on chemistry and biochemistry, in particular in the cited statements from Lehninger s textbook, the intermediate substance of the second kind is identified with highly reactive particles (intermediate products of the first kind). This mistake is based on fuzziness of the chemical induction definition and identification of conjugated reactions with consecutive ones. As a result, Lehninger has concluded that the energy transfer via general intermediate product is the universal property of consecutive reactions. ... 

Buffers are solutions that tend to resist changes in their pH as acid or base is added. Typically, a buffer system is composed of a weak acid and its conjugate base. A solution of a weak acid that has a pH nearly equal to its by definition contains an amount of the conjugate base nearly equivalent to the weak acid. Note that in this region, the titration curve is relatively flat (Figure 2.15). Addition of H then has little effect because it is absorbed by the following reaction ... 

The values of Hn and E are zero for water, by virtue of the constants 1.74 and 2.60. In these definitions, pKa refers to the acid ionization constant of the conjugate acid of the nucleophile, and E° to the standard electrode potential for the two-electron half-reaction ... 

The term carbometallation was most probably coined only about a quarter of a century ago.1 However, the history of those reactions that can be classified as carbometallation reactions is much older. If one includes not only the Ziegler-Natta-type organometallic alkene polymerization reactions2 but also various types of organometallic conjugate addition reactions,3 carbometallation collectively is easily more than a century old. In its broadest definition, carbometallation may be defined as a process of addition of a carbon-metal bond to a carbon-carbon multiple bond. As such, it may represent either a starting material-product relationship irrespective of mechanistic details or an actual mechanistic microstep of carbon-metal bond addition to a carbon-carbon metal multiple bond irrespective of the structure of the product eventually formed. 

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