Functional groups amides

In Eq. (16 i denotes an atom up to lour non-rotatable bonds away from the proton and is the total number of those atoms. A bond is deRned as non-rotatable if it belongs to a ring, to a. T-system, or to an amide functional group q- is the partial atomic charge of the atom i, and is the 3D distance between the proton j and the atom i. Figure 10.2-5 shows an example of a proton RDF descriptor. 

Amides, like esters, are abundant in all living organisms—proteins, nucleic acids, and many pharmaceuticals have amide functional groups. The reason for this abundance of amides, of course, is that they are stable to the conditions found in living organisms. Amides are the least reactive of the common acid derivatives and undergo relatively few nucleophilic acyl substitution reactions. 

In the second part of this activity, you will prepare nylon, which is a polyamide with many amide functional groups. A common method for preparing amides is the reaction of a carboxylic-acid chloride with an amine, as in RCOCI + R NH2 - RCONHR + HCI. 

The presence of the amide functional group is indicated by observations of successive losses of NH3 and OH (as water) from the molecular ion to yield ultimately the ion at m/e 443. The loss of water at m/e 460 appears to be slightly favored over the competing loss of NH3 at m/e 462 from the abundances of the respective ions. 

The N-H protons of primary and secondary amides are slow to exchange and require heating or base catalysis and this is one way an amide functional group can be distinguished from other functional groups. 

Mercury(II) oxide dissolves in an aqueous solution of acetamide forming mercury(II) acetamide. In this reaction, mercury replaces both the hydrogen atoms of the amide functional group, forming covalent N—Hg bond ... 

There is a vast range of chemistry of functionalised thiols that act as sensitiser electrode coatings in sensing. To take just one example, a ferrocene derived thiol receptor containing amide functional groups... 

Monomers derived from 10-undecenoic acid with amide functional groups have been polymerized via ADMET as well [133]. However, the low tolerance of... 

Uracil-type compounds are insoluble in common organic solvents. Radicals R4 in 168 have been used to permit a more facile allylation or rearrangement to 167, as shown in Scheme 37). Further transformation into the amide functional group permits preparation of 169, and finally 170 (93ACS72). 

The nasal decongestant Benzedrex, propylhexedrine, is shown below. Does this compound contain an amine or an amide functional group ... 

Many advances in organic chemistry involve making and using derivatives of carboxylic acids. Proteins are bonded by amide functional groups, and chemists have created synthetic amides that emulate the desirable properties of proteins. For example, the nylon in a climbing rope is a synthetic polyamide that emulates the protein in a spider s web. All the penicillin and cephalosporin antibiotics are amides that extend the antimicrobial properties of naturally occurring antibiotics. 

In this reaction the H and OH highlighted in bold have been removed to form a molecule of water. The carbonyl of the amino acid on the left formed a bond with the nitrogen atom in the amino acid on the right. The amide functional group was formed in this dehydration synthesis reaction. Notice the ends of the newly formed dipeptide. There exists another amine group and carboxylic acid group at the ends of this chain to join with other amino acids and lengthen the chain. 

Reaction of the same functionalised imidazolium salt with PdCl produced interesting results [123], In the presence of pyridine as base, the simple palladium(ll) carbene adduct was formed (see Figure 4.42), but when K COj was used as base, activation of the amide functional groups produced the corresponding homoleptic complexes, as a mixture of the cis and trans isomers. 

Proteins identified in DOM contribute only a smaU fraction of N to total DON. Therefore, future studies should also seek to improve our abUity to recover and quantify marine, dissolved proteins. For example. Section IIIc discussed the abundance of amide-N resonances in the N-NMR spectrum of HMWDON proteins are a Ukely source of these resonances but current inventories based on amino acid analyses and protein mass spectrometry are too low. Alternatively, protein-N may indeed be rare in HMWDOM and other molecule could be responsible for the amide-N identified in HMWDON. The next section focuses on polysaccharides as some of these biochemicals can contain amide functional groups. 

Although penicillin G has two amide functional groups, one is much more reactive than the other. Which amide is more reactive and why ... 

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