language-icon Old Web
English
Sign In

Imine

An imine (/ɪˈmiːn/ or /ˈɪmɪn/) is a functional group or chemical compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen (H) or an organic group (R). If this group is not a hydrogen atom, then the compound can sometimes be referred to as a Schiff base. The carbon atom has two additional single bonds. The term 'imine' was coined in 1883 by the German chemist Albert Ladenburg.Primary aldimineSecondary aldiminePrimary ketimineSecondary ketimineAziridine and its derivatives are sometimes referred to as imines. An imine (/ɪˈmiːn/ or /ˈɪmɪn/) is a functional group or chemical compound containing a carbon–nitrogen double bond. The nitrogen atom can be attached to a hydrogen (H) or an organic group (R). If this group is not a hydrogen atom, then the compound can sometimes be referred to as a Schiff base. The carbon atom has two additional single bonds. The term 'imine' was coined in 1883 by the German chemist Albert Ladenburg. Usually imines refer to compounds with the connectivity R2C=NR, as discussed below. In the older literature, imine refers to the aza analogue of an epoxide. Thus, ethyleneimine is the three-membered ring species C2H4NH. Imines are related to ketones and aldehydes by replacement of the oxygen with an NR group. When R = H, the compound is a primary imine, when R is hydrocarbyl, the compound is a secondary imine. Imines exhibit diverse reactivity and are commonly encountered throughout chemistry. When R3 is OH, the imine is called an oxime, and when R3 is NH2 the imine is called a hydrazone. A primary imine in which C is attached to both a hydrocarbyl and a H is called a primary aldimine; a secondary imine with such groups is called a secondary aldimine. A primary imine in which C is attached to two hydrocarbyls is called a primary ketimine; a secondary imine with such groups is called a secondary ketimine . One way of naming aldimines is to take the name of the radical, remove final 'e', and add '-imine', for example ethanimine. See the aldimine article for other naming conventions. Alternately, an imine is named as a derivative of a carbonyl, adding the word 'imine' to the name of a carbonyl compound whose oxo group is replaced by an imino group, for example sydnone imine and acetone imine (an intermediate in the synthesis of acetone azine). N-Sulfinyl imines are a special class of imines having a sulfinyl group attached to the nitrogen atom. Imines are typically prepared by the condensation of primary amines and aldehydes and less commonly ketones.In terms of mechanism, such reactions proceed via the nucleophilic addition giving a hemiaminal -C(OH)(NHR)- intermediate, followed by an elimination of water to yield the imine (see alkylimino-de-oxo-bisubstitution for a detailed mechanism). The equilibrium in this reaction usually favors the carbonyl compound and amine, so that azeotropic distillation or use of a dehydrating agent, such as molecular sieves or magnesium sulfate, is required to push the reaction in favor of imine formation. In recent years, several reagents such as Tris(2,2,2-trifluoroethyl)borate , pyrrolidine or titanium ethoxide have been shown to catalyse imine formation.

[ "Photochemistry", "Catalysis", "Organic chemistry", "Inorganic chemistry", "imine ligands", "Hydroxycyclopentadienyl ruthenium hydride", "NAPQI", "2-pyridineformamide", "ethylene imine" ]
Parent Topic
Child Topic
    No Parent Topic