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In general, in a group across the periodic table, the more basic the ion (the higher the pK a of the conjugate acid) the more reactive it is as a nucleophile. Within a series of nucleophiles with the same attacking element (e.g. oxygen), the order of nucleophilicity will follow basicity.
The physical manifestation of leaving group ability is the rate at which a reaction takes place. Good leaving groups give fast reactions. By transition state theory, this implies that reactions involving good leaving groups have low activation barriers leading to relatively stable transition states.
Normal and α-nucleophiles [1] The alpha effect refers to the increased nucleophilicity of an atom due to the presence of an adjacent (alpha) atom with lone pair electrons . [ 2 ] This first atom does not necessarily exhibit increased basicity compared with a similar atom without an adjacent electron-donating atom, resulting in a deviation from ...
An application of HSAB theory is the so-called Kornblum's rule (after Nathan Kornblum) which states that in reactions with ambident nucleophiles (nucleophiles that can attack from two or more places), the more electronegative atom reacts when the reaction mechanism is S N 1 and the less electronegative one in a S N 2 reaction.
In chemistry, a nucleophilic substitution (S N) is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile).
The improved pKa range of "soft" nucleophiles is critical because these nucleophiles are the only ones that have been explored [18] [19] for enantioselective reactions until very recently [20] (although non-enantioselective reactions of "hard" nucleophiles have been known for some time [21]). By increasing the scope of pronucleophiles that act ...
Tyler. Another name that exploded in popularity during the 1990s, Tyler is an English name with a literal meaning: "maker of tiles." In the 1990s, just over 262,000 Tylers were born in the United ...
The most commonly used nucleophiles are the hydroxyl (OH) of serine and the thiol/thiolate ion (SH/S −) of cysteine. [2] Alternatively, threonine proteases use the secondary hydroxyl of threonine, however due to steric hindrance of the side chain's extra methyl group , such proteases use their N -terminal amide as the base rather than a ...