Biologically important amines functional groups

The synthesis of fluorinated analogs of biologically important amines has been explored extensively. Their direct preparation is difficult since most of the common fluorination agents can also react with the amino group. However, by the use of appropriate solvents, like liquid hydrogen fluoride which protects the amine functionality by protonation, successful... 

Although the amine functional group is separated from the ester oxygen by more than two carbons, the conformation assumed by the tropine ring orients these two atoms such that the intervening distance is similar to that in acetylcholine. One important structural difference between atropine and acetylcholine, both of which are esters of amino alcohols, is the size of the acyl portion of the molecules. Based on the assumption that size was a major factor in blocking action, many substituted acetic acid esters of amino alcohols were prepared and evaluated tor biological activity. 

The first reason for desiring the synthesis of such compounds is that they include such biologically important moieties as purines, prymidines and select alpha-amino acids Second, there are a number of antitumoral agents which possess no amine or one amine functional group but additional amide groups ... 

Formaldehyde travels in the blood throughout the body and reacts with proteins, destroying their biological function. Methanol causes blindness because formaldehyde destroys an important visual protein. Formaldehyde reacts with an amine functional group of the amino acid lysine in a protein, called rhodopsin. Formaldehyde also reacts with amino groups in other proteins, including many enzymes, and the loss of the function of these biological catalysts causes death. 

Proteins, among the most important and versatile biological compounds, consist of nitrogen-containing molecules called a-amino acids. In proteins, each amine functional group of one tt-amino acid is bonded to the carbonyl carbon of another a-amino acid in a chain of amino acyl groups that... 

Treatment of phenol with 1,2-diols and excess of cyclopentene (Sequiv.) in the presence of a well-defined cationic ruthenium hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4- (1 mol%) in toluene at 100 C for 8-12h led to the formation of benzofuran derivatives (Eq. (7.18)) [24]. The catalytic C-H couphng method exhibited a broad substrate scope, tolerated carbonyl and amine functional groups, obviated the use of any expensive and often toxic metal oxidants, and liberated water as the only by-product. Furthermore, excellent regioselective addition of the linear 1,2-diols were observed, which yielded the -substituted benzofuran products exclusively. Such dehydrative C—H alkenylation and annulation reactions could be applied for a number of functionalized phenol and alcohol substrates of biological importance. 

There are some small organic molecules with very simple chemical formulas that have proved to be important for biological applications. Urea or carbamide is such an organic compound, with the chemical formula (NH2)2CO. The molecule has two amine (-NH2) groups joined by a carbonyl (C=0) functional group. 

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