Aminal ring

Reaction between lactones and ammonia or amines ring expansion of lactams... 

The most important polyamine with cyclic amine ring on the main chain, is poly(dimethyldiallyammonium chloride) (DMDAC) (13). Due to its cationic charges, poly(dimethyldiallylammonium chloride) can... 

The combination of allylic amination, ring-closing metathesis, and a free radical cyclization provides a convenient approach to the dihydrobenzo[b]indoline skeleton, as illustrated in Scheme 10.10. The rhodium-catalyzed aUylic amination of 43 with the lithium anion of 2-iodo-(N-4-methoxybenzenesulfonyl)arrihne furnished the corresponding N-(arylsulfonyl)aniline 44. The diene 44 was then subjected to ring-closing metathesis and subsequently treated with tris(trimethylsilyl)silane and triethylborane to afford the dihydrobenzojhjindole derivative 46a in 85% yield [14, 43]. 

RDX, Cyclonite, Hexahydro-l,3,5-trinitro-l,3,5-triazine under Secondary Aliphatic Amines Ring-Substituted Aromatics Saturated Alkyl Halides Secondary Alcohols... 

During a study of dihydrocoumarins (68JOC1202) it was observed that 4-(2-bromoethyl)-3,4-dihydrocoumarin (291) was converted into a 4-substituted chroman on reaction with an amine. Ring opening occurs through nucleophilic attack at C-2 and this is followed by an intramolecular nucleophilic substitution. In a similar manner, chroman-4-ylacetic acid results on reaction with potassium hydroxide in methanol. 

Keywords thiohydantoin, amine, ring opening, waste-free, gas-solid reaction, thioureido-acetamide... 

Keywords imides, amines, ring opening, cyclization, gas-solid reaction, diamides... 

The generic term refers to a large variety of different products all of which have a cyclic amine ring in the molecule. 

B) Amine rings which are cyclised tailor made during the synthesis of the pesticide. 

Compared to t.l.c. results the effective yields in the two step process seem to be much better than if the products are isolated and purified. There are indications that during chromatography, some of the nitro lactams are destroyed. In competition with this reductive amination/ring enlargement reaction is the enamine expansion route, discussed at the beginning of this Chapter (Scheme VII/6). Therefore the imine in this sequence must be reduced immediately after its formation. 

The liposidomycins are a family of novel lipid-containing nucleoside antibiotics which inhibit bacterial peptidoglycan synthesis. A crucial component of their stmctures is a substituted l,4-diazepan-3-one moiety. As part of work to assign stereochemistry in these antibiotics, analogues of this moiety have been synthesised using a reductive amination/ring cyclisation approach <03H(59)107>. The compounds synthesised were 57 and 58. 

For polypyrroles and polythiophenes, n is usually ca. 3 for optimal conductivity, ie. there is a positive charge on every third or fourth pyrrole or thiophene along the polymer chain, near which the dopant anion A is electrostatically attached. For polyanilines, the ratio of reduced (amine) and oxidised (imine) units in the polymer is given by the y/( 1 - y) ratio. The conducting emeraldine salt form of polyaniline has y = 0.5, i.e. there are equal numbers of imine and amine rings present. 

Using primary aliphatic amines, ring opening of isocoumarin-derived thiolactones (3) according to equation (2) offers a convenient access to o-(2-oxoalkyl)thiobenzamides (4) with yields in the 80% range aromatic amines give side reactions. ... 

Similar plots can be obtained from kinetic data of unsaturated polyester resins (24, 25). This behavior is independent of the identity of the nitrogen substituents of the amine or the monomer. Previous publications from this laboratory have pointed out that the a+ value of the amine ring substituent yielding maximum reactivity, i.e., minimum polymerization (or cure) time, occurs at approximately -0.2 in the cases examined (26-29). The optimum value is anticipated to be fairly insensitive to the type of monomer and experimental conditions. 

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