Search results
Results From The WOW.Com Content Network
Many schemes attempting to quantify relative nucleophilic strength have been devised. The following empirical data have been obtained by measuring reaction rates for many reactions involving many nucleophiles and electrophiles. Nucleophiles displaying the so-called alpha effect are usually omitted in this type of treatment. [citation needed]
In S N 2 reactions, there are a few conditions that affect the rate of the reaction. First of all, the 2 in S N 2 implies that there are two concentrations of substances that affect the rate of reaction: substrate (Sub) and nucleophile. The rate equation for this reaction would be Rate=k[Sub][Nuc].
General reaction scheme for the S N 1 reaction. The leaving group is denoted "X", and the nucleophile is denoted "Nu–H". The unimolecular nucleophilic substitution (S N 1) reaction is a substitution reaction in organic chemistry.
There are two factors which complicate determining the mechanism of nucleophilic substitution reactions at secondary carbons: Many reactions studied are solvolysis reactions where a solvent molecule (often an alcohol) is the nucleophile.
In many nucleophilic reactions, addition to the carbonyl group is very important. In some cases, the C=O double bond is reduced to a C-O single bond when the nucleophile bonds with carbon. For example, in the cyanohydrin reaction a cyanide ion forms a C-C bond by breaking the carbonyl's double bond to form a cyanohydrin.
There are five main types of acyl derivatives. Acid halides are the most reactive towards nucleophiles, followed by anhydrides, esters, and amides. Carboxylate ions are essentially unreactive towards nucleophilic substitution, since they possess no leaving group.
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 ...
There are several different categories of nucleophiles with different attacking atoms (e.g. oxygen, carbon, nitrogen) and each of these atoms has different nucleophilic characteristics. [3] The Edwards equation attempts to account for this additional parameter by introducing a polarizability term.