Ketimines nitriles

Other modifications of the polyamines include limited addition of alkylene oxide to yield the corresponding hydroxyalkyl derivatives (225) and cyanoethylation of DETA or TETA, usuaHy by reaction with acrylonitrile [107-13-1/, to give derivatives providing longer pot Hfe and better wetting of glass (226). Also included are ketimines, made by the reaction of EDA with acetone for example. These derivatives can also be hydrogenated, as in the case of the equimolar adducts of DETA and methyl isobutyl ketone [108-10-1] or methyl isoamyl ketone [110-12-3] (221 or used as is to provide moisture cure performance. Mannich bases prepared from a phenol, formaldehyde and a polyamine are also used, such as the hardener prepared from cresol, DETA, and formaldehyde (228). Other modifications of polyamines for use as epoxy hardeners include reaction with aldehydes (229), epoxidized fatty nitriles (230), aromatic monoisocyanates (231), or propylene sulfide [1072-43-1] (232). 

Fluorinated heterodienophiles and heterodienes Diels-Alder reactions in which the dienophiles have perfluoroalkyl-substituted multiple bonds between carbon and a heteroatom are quite common Reported earlier were reactions of perfluoroketones, thiones, ketimines, thioesters, nitroso compounds, and nitriles [9] Examples of a-fluoroimines [107], co-hydroperfluorothioaldehydes [108], perfluorosulfines [109, IIO], and selenocarbonyidifluoride [III] (equations 89-92) have been reported recently... 

RR C=NLi) . They can be prepared in high yield either by the addition of an organolithium compound across the triple bond of a nitrile (equation (1)) or by lithiation of a ketimine (equation (2)). 

Two unique type Had syntheses of pyrroles that were reported both involved cyclopropane fragmentations. The first allowed for a synthesis of 2-arylpyrroles <06SL2339>. In the event, treatment of stannylcyclopropane 25 with -BuLi followed by benzonitrile produced 2-phenylpyrrole 26 via tin-lithium exchange, addition to the nitrile, ring fragmentation of ketimine intermediate, intramolecular condensation, and loss of dibenzylamine. 

Aldimines, Ketimines, and Related Compounds as Dipolarophiles Reactions of aldimines with nitrile oxides proceed readily to give 1,2,4-oxadiazolines independently of the nature of substituents both in dipole and dipolarophile molecules. 1,2,4-Oxadiazolines were prepared by the regiospe-cihc 1,3-dipolar cycloaddition of nitrile oxides with fluoro-substituted aldimines (295). Phosphorylnitrile oxides gave with azomethines, PhCH NR, phosphory-lated 1,2,4-oxadiazolines 129 (296). Expected 1,2,4-oxadiazolines were also obtained from azomethines, derived from 4-formylcoumarine (179) and 1,3-diphenylpyrazole-4-carbaldehyde (297). 

This procedure is a modification of the method employed by Moureu and Mignonac,3 who first reported the preparation of ketimines via Grignard-nitrile complexes. The use of methanol... 

Addition of RMgBr to nitriles. Grignard reagents react with nitriles slowly if at all, but even r-butylmagnesium chloride will add to nitriles in refluxing THF when catalyzed by a copper(I) salt. The adduct can be converted to a ketimine by anhydrous protonation, to a primary amine by reduction (Li/NH,), or to a ketone by hydrolysis. The actual reagent may be a cuprate such as R3Cu(MgX)2. 

The ketone synthesis of Houhen and Hoesch, which is based on the principle of the Gattermann reaction, proceeds very smoothly and gives very favourable results, especially in the case of polyhydric phenols. In this synthesis nitriles are used. Here it is the iminochlorides R—C=NH which are converted into ketimines and then into ketones, a... 

Formally related reactions are observed when anthracene [210] or arylole-fines [211-213] are reduced in the presence of carboxylic acid derivatives such as anhydrides, esters, amides, or nitriles. Under these conditions, mono- or diacylated compounds are obtained. It is interesting to note that the yield of acylated products largely depends on the counterion of the reduced hydrocarbon species. It is especially high when lithium is used, which is supposed to prevent hydrodimerization of the carboxylic acid by ion-pair formation. In contrast to alkylation, acylation is assumed to prefer an Sn2 mechanism. However, it is not clear if the radical anion or the dianion are the reactive species. The addition of nitriles is usually followed by hydrolysis of the resulting ketimines [211-213]. 

Aliphatic nitriles also react with aliphatic Grignard reagents to give high yields of the ketimine when the complex reaction product is slowly decomposed with anhydrous methanol rather than anhydrous ammonia or aqueous decompositions [15]. 

Phenols are also known to be able to condense with nitriles to give phenolic ketimines as shown in Eq. (2) [17]. The reaction between the phenol and nitrile is carried out in ether solution when hydrogen chloride gas is added to the saturation point. Less reactive phenols also require the presence of zinc chloride. 

When a nitrile is reacted with an aromatic compound in the presence of HC1, in the additional presence of ZnC or AICI3, a ketimine salt is formed, which after subsequent hydrolysis gives an aromatic ketone ... 

Reaction XXX. Condensation of a Nitrile with a Phenol or a Phenol Ether and Hydrolysis of the resulting Ketimine Hydrochloride to a Ketone. 

In 1915 Hoesch showed that the condensation of a nitrile with a phenolic compound led to the formation of a ketimine hydrochloride which could be easily hydrolysed to give a ketone. 

The phenol and the nitrile are dissolved in dry ether, and anhydrous hydrogen chloride led in. On. standing, the hydrochloride of the ketimine... 

Wu and co-workers developed a synthesis of benzannulated nitrogen heterocycles 120 and 121 based on the addition of sodium methoxide to 2-alkynylbenzo-nitriles 118 in methanol, followed by the Pd(PPh3)4-catalyzed heteroannulation of ketimine intermediate 119 with aryl iodides [104]. The 5-exo versus 6-endo mode of cyclization leading to isoindoles 120 or isoquinolines 121, respectively, proved to be dependent on the nature of the substituent on the terminal alkyne carbon. 2-(2-Phenylethynyl) benzonitrile 118a underwent exclusive 5-exo cyclization whereas 2-(l-hexynyl)benzonitrile 118b led to mixtures of isomers with a marked preference for the 6-endo mode of cyclization. This endo/exo balance was attributed to steric interactions between the entering group and the substituent on the terminal alkyne carbon (Scheme 8.49). 

Furthermore, treatment of 194 a, b with potassium cyanide in the presence of aqueous acetic acid gave the cyclopropylnitrile 197 in 62-73% yield. This nitrile was then allowed, to react with cyclopropyllithium in ether at —78 °C to give the cyclopropyl ketimine 198, Eq. (62)129). 

The Af,0-enolato ligands 146 are usually prepared by deprotonation of the corresponding conjugated acids which, for ketimines, can be formulated as consisting of the tautomeric forms 147-149. However, some of them have been prepared (i) by reacting nitriles with the corresponding S-diketonato complexes, or with 2-oxoalkyl or enolato complexes (Section in.C, Chapter 6 ) or (ii) by oxidation of diketoamines with metal complexes in the presence of a base (Section n.B.3). Although the most abundant tautomeric form of a S-ketimine depends on the nature of the substituents, they wiU be represented as 148. 

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