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The general structure of an enamine. An enamine is an unsaturated compound derived by the condensation of an aldehyde or ketone with a secondary amine. [1] [2] Enamines are versatile intermediates. [3] [4] Condensation to give an enamine. [5] The word "enamine" is derived from the affix en-, used as the suffix of alkene, and the root amine.
Amine. In chemistry, amines (/ ə ˈ m iː n, ˈ æ m iː n /, [1] [2] UK also / ˈ eɪ m iː n / [3]) are compounds and functional groups that contain a basic nitrogen atom with a lone pair.Formally, amines are derivatives of ammonia (NH 3), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group [4] (these may respectively be called alkylamines ...
In recent years, several reagents such as Tris(2,2,2-trifluoroethyl)borate [B(OCH 2 CF 3) 3], [14] pyrrolidine [15] or titanium ethoxide [Ti(OEt) 4] [16] have been shown to catalyse imine formation. Rarer than primary amines is the use of ammonia to give a primary imine. [17] In the case of hexafluoroacetone, the hemiaminal intermediate can be ...
Compared to amines, amides are very weak bases. While the conjugate acid of an amine has a pK a of about 9.5, the conjugate acid of an amide has a pK a around −0.5. Therefore, compared to amines, amides do not have acid–base properties that are as noticeable in water. This relative lack of basicity is explained by the withdrawing of ...
In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl (C=O) functional group by formaldehyde (H−CHO) and a primary or secondary amine (−NH 2) or ammonia (NH 3). [1] The final product is a β-amino-carbonyl compound also known as a Mannich base.
Reductive amination (also known as reductive alkylation) is a form of amination that converts a carbonyl group to an amine via an intermediate imine. The carbonyl group is most commonly a ketone or an aldehyde. It is a common method to make amines and is widely used in green chemistry since it can be done catalytically in one-pot under
Amidines are much more basic than amides and are among the strongest uncharged/unionized bases. [6] [7] Protonation occurs at the sp 2-hybridized nitrogen. This occurs because the positive charge can be delocalized onto both nitrogen atoms. The resulting cationic species is known as an amidinium ion [8] and possesses identical C-N bond lengths.
Most common imides are prepared by heating dicarboxylic acids or their anhydrides and ammonia or primary amines. The result is a condensation reaction: [5] (RCO) 2 O + R′NH 2 → (RCO) 2 NR′ + H 2 O. These reactions proceed via the intermediacy of amides. The intramolecular reaction of a carboxylic acid with an amide is far faster than the ...