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A classic example of NGP is the reaction of a sulfur or nitrogen mustard with a nucleophile, the rate of reaction is much higher for the sulfur mustard and a nucleophile than it would be for a primary or secondary alkyl chloride without a heteroatom. [5] Ph−S−CH 2 −CH 2 −Cl reacts with water 600 times faster than CH 3 −CH 2 −CH 2 ...
A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. 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 ...
The carbonyl center in thioesters is more reactive toward amine than oxygen nucleophiles, giving amides: Thioesters are components of the native chemical ligation method for peptide synthesis. This reaction is exploited in native chemical ligation, a protocol for peptide synthesis. [8] In a related reaction, thioesters can be converted into ...
Reactions such as this, with an alkoxide as the nucleophile, are known as the Williamson ether synthesis. Synthesis of macrocidin A via S N 2 etherification. If the substrate that is undergoing S N 2 reaction has a chiral centre, then inversion of configuration (stereochemistry and optical activity) may occur; this is called the Walden inversion.
This is an accepted version of this page This is the latest accepted revision, reviewed on 1 February 2025. This article is about the chemical element. For other uses, see Sulfur (disambiguation). Chemical element with atomic number 16 (S) Sulfur, 16 S Sulfur Alternative name Sulphur (pre-1992 British spelling) Allotropes see Allotropes of sulfur Appearance Lemon yellow sintered microcrystals ...
Also, because the intermediate is partially bonded to the nucleophile and leaving group, there is no time for the substrate to rearrange itself: the nucleophile will bond to the same carbon that the leaving group was attached to. A final factor that affects reaction rate is nucleophilicity; the nucleophile must attack an atom other than a hydrogen.
A sulfur nucleophile improved the enzymes transferase activity (sometimes called subtiligase). Selenium and tellurium nucleophiles converted the enzyme into an oxidoreductase . [ 51 ] [ 52 ] When the nucleophile of TEV protease was converted from cysteine to serine, it protease activity was strongly reduced, but was able to be restored by ...
The biological use of sulfur as an alternative to carbon is purely hypothetical, especially because sulfur usually forms only linear chains rather than branched ones. (The biological use of sulfur as an electron acceptor is widespread and can be traced back 3.5 billion years on Earth, thus predating the use of molecular oxygen. [28]