Imines and imides

Benzylideneanilines have been added across 2,3-dihydrofurans to produce bicyclic azetidines regio- and stereoselectively a zwitterionic mechanism is proposed. An extensive range of reaction parameters have been calculated for the Mannich reaction of benzoxazole with formaldehyde/dimethylamine. A molybdenum bis(imide) has been used to catalyse C=N bond formation in imine-imine metathesis reactions of synthetic interest the approach has been extended to alkylidene-imine, imide-imine, and imide-imide metatheses. 1-Substituted 1-phenyl-... 

Section 15.7 contains tables of magnetic data obtained from anion radicals of compounds fliat don t comfortably fall into any of the previous sections. The subsection on fullerene anion radicals requires a special note as there are several papers of around the same period which vary shghtly in the preparation, solvent or physical parameters of the measurements. As the only data in many cases is the g factor it was decided to include the majority of these entries even though they relate to the same species. The data have been divided into the following subsections sulphides and sulphones, imines and imides, fullerenes, tetracyanoquinodi-methanes, phenylcarbonitriles, phosphaaUcenes and alkylcyclosilanes. Some of these subsections have been further subdivided. 

N-Organosilyl Imines and Imides This group of compounds includes the organosilyl derivatives of ketenimines, ketimines, sulphodiimines, carbodiimides, iminophos-phoranes, etc. Tris(trimethylsilyl)ketenimine [380] (85% b.p. 65-70°C at 0.13 kPa = 1 mm Hg) is prepared from acetonitrile, r-butyllithium and chlorotrimeth-... 

Phosphorus ylids also react in a similar manner with the C=0 bonds of ketenes/ isocyanates, and certain anhydrides and imides, the N=0 of nitroso groups, and the C=N of imines, for example. 

Imidates are a different type of imine. Conceptually, imidates result from dehydration after condensation of a primary amido N-atom with the carbonyl of an ester function, although the actual synthetic route is often via an ortho ester (RC(OR )3). A large variety of A-sulfonyl imidates have been prepared and examined for their value as potential prodrugs containing a sulfonamide or an ester moiety [101][102], The hydrolysis of such compounds,... 

Aromatic imines are usually intensely yellow. Other possible byproducts which may be formed in the polyimide system are the previously discussed isoimide and imide-imine formed by the following reaction. 

Compounds able to undeigo solvolysis to sufficiently stable cations are reduced via these carbocations by NaBH4 in alcoholic media sometimes in the presence of acid. Diarylketones (Section 3.2) or the di- or triarylcarbinols are reduced to hydrocarbons (Section 2.4), imines and the iminium salts are reduced to amines (Sections 3.3.1, 3.3.2), and imides to a -hydroxy amides (Section 3.2.8). 

Cyciizations of compounds containing the following pairs of functions are also included in this chapter acylamine and alkene, alkene and imidate, alkene and imine, and alkyne and carbamate. 

Lactams can be prepared by [2 + 2] cycloadditions of mines and ketenes50- 52, iniines and ester enolatcs53, imines and silyl ketene acetals, alkenes and isocyanates54 56 and carbodi-imides and ketenes. The stereospecificity of these reactions has been extensively investigated due to the tremendous practical importance of 0-lactam antibiotics57 -59,1I3. 

The N -substituted N-imines can be prepared by the reaction of the N-aminoazonium salts, in the presence or absence of base, with anhydrides or acyl halides,8,13-17,20,21,45,46 diketene,47 diethyl malonate,48 sulfonyl chloride,8,15,49,50 /i-halovinyl ketones and esters,51-54 diethyl ethoxymeth-ylenemalonate and related compounds,53,55-57 isocyanates,17,58 thioiso-cyanates,17,58 imidoyl chlorides and imidates,59,60 nitro acetate,8,61 and active halobenzenes.62,63 Some representative pyridine -(substituted imines) prepared in this way are shown in Scheme 1. 

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