Search results
Results from the WOW.Com Content Network
Lithium amides are usually prepared in the laboratory through the addition of a titrated solution of n-butyllithium in hexanes to a solution of the amine in ether. Dry glassware and inert atmosphere are required for these reactions. Alternatively, lithium amides may be prepared by the direct action of lithium on the corresponding amine.
Amides are stable to water, and are roughly 100 times more stable towards hydrolysis than esters. [citation needed] Amides can, however, be hydrolyzed to carboxylic acids in the presence of acid or base. The stability of amide bonds has biological implications, since the amino acids that make up proteins are linked with amide
Acid–base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules ...
In enzymology, an amidase (EC 3.5.1.4, acylamidase, acylase (misleading), amidohydrolase (ambiguous), deaminase (ambiguous), fatty acylamidase, N-acetylaminohydrolase (ambiguous)) is an enzyme that catalyzes the hydrolysis of an amide. In this way, the two substrates of this enzyme are an amide and H 2 O, whereas its two products are ...
The two major resonance forms of an amide. Another factor that plays a role in determining the reactivity of acyl compounds is resonance. Amides exhibit two main resonance forms. Both are major contributors to the overall structure, so much so that the amide bond between the carbonyl carbon and the amide nitrogen has significant double bond ...
Next, the carbanion resulting from the benzylic hydrogen extraction performs a nucleophilic attack on the electrophilic carbonyl carbon of the amide group. When this occurs, the pi-bond of the amide is converted into a lone pair, creating a negatively charged oxygen. After these initial steps, strong base is no longer required and hydrolysis ...
HATU is commonly encountered in amine acylation reactions (i.e., amide formation). Such reactions are typically performed in two distinct reaction steps: (1) reaction of a carboxylic acid with HATU to form the OAt-active ester; then (2) addition of the nucleophile (amine) to the active ester solution to afford the acylated product.
The deprotonation of the Zn 2+ coordinated water by Glu 270 provides an activated hydroxide nucleophile which attacks the amide carbonyl group in the peptide bond in a nucleophilic addition. The negatively charged intermediates that are formed during hydrolysis are stabilized by the Zn 2+ ion. The interaction between the carbonyl group and the ...