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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(NH 3 (in which the bond angle between the nitrogen and hydrogen is 170°), wherein one or more hydrogen atoms have been replaced by a substituent such as an ...
A variety of amines and nitrogen heterocycles are useful bases of moderate strength (pK a of conjugate acid around 10-13) . N,N-Diisopropylethylamine (DIPEA, also called Hünig's Base [1]), pK a = 10.75
Typical Lewis bases are conventional amines such as ammonia and alkyl amines. Other common Lewis bases include pyridine and its derivatives. Some of the main classes of Lewis bases are amines of the formula NH 3−x R x where R = alkyl or aryl. Related to these are pyridine and its derivatives. phosphines of the formula PR 3−x Ar x.
An organic base is an organic compound which acts as a base. Organic bases are usually, but not always, proton acceptors. They usually contain nitrogen atoms, which can easily be protonated. For example, amines or nitrogen-containing heterocyclic compounds have a lone pair of electrons on the nitrogen atom and can thus act as proton acceptors. [1]
In the Mannich reaction, primary or secondary amines or ammonia react with formaldehyde to form a Schiff base. Tertiary amines lack an N–H proton and so do not react. The Schiff base can react with α-CH-acidic compounds (nucleophiles) that include carbonyl compounds, nitriles, acetylenes, aliphatic nitro compounds, α-alkyl-pyridines or imines.
N,N-Diisopropylethylamine, or Hünig's base, is an organic compound that is a tertiary amine. It is named after the German chemist Siegfried Hünig . It is used in organic chemistry as a non-nucleophilic base. It is commonly abbreviated as DIPEA, DIEA, or i-Pr 2 NEt.
Schiff bases are common enzymatic intermediates where an amine, such as the terminal group of a lysine residue, reversibly reacts with an aldehyde or ketone of a cofactor or substrate. The common enzyme cofactor pyridoxal phosphate (PLP) forms a Schiff base with a lysine residue and is transaldiminated to the substrate(s). [7]
Strong bases hydrolyze in water almost completely, resulting in the leveling effect." [7] In this process, the water molecule combines with a strong base, due to the water's amphoteric ability; and, a hydroxide ion is released. [7] Very strong bases can even deprotonate very weakly acidic C–H groups in the absence of water.