Amino and Imino Groups

The reaction of 1,2-diazinamines with electrophiles is well studied while the substitution of amines-imines by nucleophiles is a highly nonstandard process. Nevertheless, even in the latter class new examples appeared since CHEC-II(1996) 1996CHEC-II(6)1 . A new section dealing with the so-called f-amino effect was added since many examples on 1,2-diazines have appeared since the mid-1990s. 

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In summary, the results for the case of the polymer indicate that only the amino-nitrogens interacts with the ITO surface while the model studies demonstrates that both amino- and imino-groups reacts with ITO. Thus, further investigations arc necessary in order to obtain a complete picture. Studies using model systems that contain the whole cmeraldine base sequence have been initiated [114],... 

Amino and imino groups. Amino thieno benzoxepine 163 (Scheme 32, Section 2.2.3) can be smoothly transformed into the corresponding amides and urea (1994JCS(P1)2191). The dimethylamino substituted pyrrolo-benzoxazepine... 

Reaction of amino and imino groups with nucleophiles... 

Only in the case of a, to - dicyanoalkanes hydrogenation, there is a possibility of intramolecular condensation of intermediate [1] between amino and imino group. Such a condensation leading to an aminal [2] prone to ammonia loss, gives rise to 1-aza-l-cyclo-heptene 3. Hydrogenation of this intermediate leads to azacyclo-heptane 4. 

The cis stereochemistry observed is better supported starting from 10 rather than from 11. In the first case intramolecular hydrogen bonding between amino and imino group favors the cis configuration leading to cis AMCPA as the major compound. 

Methods for the protection of the amino and imino groups are considered in Section 5.16.7, p. 784. 

SOME METHODS FOR THE PROTECTION OF THE AMINO AND IMINO GROUPS... 

Only a restricted selection of the very great number of methods for the protection of the amino and imino groups is possible here. These have often been developed for the protection of the amino group in an amino acid for the purpose of peptide synthesis. Those considered below are (a) AT-acyl derivatives (b) carbamates and (c) phthalimides. 

The amino- and imino-groups coupled with an aromatic ring represent a basic and equally a oxidizable (electron donating) part of the... 

General survey Benzenoid substituents Alkyl groups Aryl substituents Carboxy substituents Oxygen substituents Amino and imino groups Thio- and thiol substituents... 

It also has become clear that the protons of the amino and imino groups of the base derivatives can exchange directly in non-aqueous atomosphere, if appropriate conditions are satisfied. Although the experiment were carried out on the monomer systems, there is no reason to deny the proton exchange in interior of nucleic acids. The exchange is possibly due to the presence of the keto-enol tautomerism, and we may estimate the frequency of tautomerism from the present date. 

These include amino and imino groups and quaternary anunonium bases, all of which may be regarded as derivatives of ammonia. There are several different types of amine according to the number of H atoms of the ammonia which have been replaced. 

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