Amides, cyclic aromatic

Figure 5 One-Dimensional H NMR Spectra of Cyclic p-Sheet Peptides Showing (a) the Amide and Aromatic Regions and (b) H Regions[121a a...

L-Amino acids are the building blocks of proteins. They are frequently grouped according to the chemical nature of their side chains. Common groupings of amino acids are aliphatic, hyd roxyl/sulfu r, cyclic, aromatic, basic, acidic and acid amides. Links to individual amino acids are given below ... 

Within the last two decades, a number of chemical structures have been proposed as metal deactivators for polyolefins. These include carboxylic acid amides of aromatic mono- and di-carboxylic acids and N-substituted derivatives such as N,N -diphenyloxamide, cyclic amides such as barbituric acid, hydrazones and bishydrazones of aromatic aldehydes such as benzaldehyde and salicylaldehyde or of o-hydroxy-arylketones, hydrazides of aliphatic and aromatic mono- and di-carboxylic acids as well as N-acylated derivatives thereof, bisacylated hydrazine derivatives, polyhydrazides, and phosphorus acid ester of a thiobisphenol. An index of trade names and suppliers of a few commercial metal deactivators is given in Appendix A4. 

The various dipolar amide resonance forms provide cyclic aromatic electron sextets. 

Kim YH, Calabrese J, McEwen C (1996) CaCls or Ca2Cl4 Complexing cyclic aromatic amide. Template effect on cyclization. J Am Chem Soc 118(6) 1545-1546... 

Considerable interest remains in catalyzed hydrogen-transfer reactions using as donor solvents alcohols, glycols, aldehydes, amides, acids, ethers, cyclic amines, and even aromatic hydrocarbons such as alkylben-... 

The reactions of ammonia or primary amines with five-membered cyclic nitronates containing the EWG -group at the C-5 atom involve deoxygenation of the nitronate fragment, aromatization of the ring, and amidation of the ester... 

Oxidative attack on a carbon-hydrogen bond of an alkyl group a to a nitrogen atom is not restricted to saturated aliphatic amines. In fact X in an X-N-CH- structural subunit can be virtually any common atomic grouping that can be found in stable organic molecules. For example, w-carbon hydrogens of Aralkyl-substituted aromatic cyclic amines (119), aryl amines (120), amides (121), amidines (122), A-nitrosodialkylamines (123), etc. are all subject to oxidative attack, carbinolamine formation, and in most cases release of an aldehyde or ketone depending on the substitution pattern (1° or 2°)... 

The only cationic surfactant (Fig. 23) found in any quantity in the environment is ditallow dimethylammonium chloride (DTDMAC), which is mainly the quaternary ammonium salt distearyldimethylammonium chloride (DSDMAC). The organic chemistry and characterization of cationic surfactants has been reported and reviewed [330 - 332 ]. The different types of cationic surfactants are fatty acid amides [333], amidoamine [334], imidazoline [335], petroleum feed stock derived surfactants [336], nitrile-derived surfactants [337], aromatic and cyclic surfactants [338], non-nitrogen containing compounds [339], polymeric cationic surfactants [340], and amine oxides [341]. 

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