Search results
Results from the WOW.Com Content Network
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. Nucleophilic describes the affinity of a nucleophile to bond with positively charged ...
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 molecule that contains the electrophile and the leaving functional group is called the substrate.
Sodium methanethiolate or sodium thiomethoxide (CH 3 SNa, MeSNa) is the sodium conjugate base of methanethiol.This compound is commercially available as a white solid. It is a powerful nucleophile that can be used to prepare methylthioether and other organic compounds like ethyl bromide.
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) is a chemical compound with the formula C 7 H 12 N 2. [1] It is an amidine base used in organic synthesis. A related compound with related functions is 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The relatively complex nature of the formal names for DBU and DBN (hence the common use of acronyms) reflects the ...
In the context of a specific chemical reaction between NH 3 and Me 3 B, a lone pair from NH 3 will form a dative bond with the empty orbital of Me 3 B to form an adduct NH 3 •BMe 3. The terminology refers to the contributions of Gilbert N. Lewis. [2] The terms nucleophile and electrophile are sometimes interchangeable with Lewis base and ...
The nucleophile is most commonly a serine or cysteine, but occasionally threonine or even selenocysteine. The 3D structure of the enzyme brings together the triad residues in a precise orientation, even though they may be far apart in the sequence ( primary structure ).
In 1962, Edwards and Pearson (the latter of HSAB theory) introduced the phrase alpha effect for this anomaly. He offered the suggestion that the effect was caused by a transition state (TS) stabilization effect: on entering the TS the free electron pair on the nucleophile moves away from the nucleus, causing a partial positive charge which can be stabilized by an adjacent lone pair as for ...
However, it has the disadvantage to be prone to trigger unexpected and undesirable side reactions that can jeopardize the experimental results. Indeed, the azide anion is a nucleophile and a redox-active species. Being prone to disproportionation, it can behave both as an oxidizing and as a reducing agent. Therefore, it is susceptible to ...