Nitrogen-containing compounds synthesis

Kuzuhara S, H Sato, N Tsubouchi, Y Ohtsuka, E Kasai (2005) Effect of nitrogen-containing compounds on polychlorinated dibenzo-p-dioxin/dibenzofuran formation through de novo synthesis. Environ Sci Technol 39 795-799. 

Addition of Ketene Acetals and Enoles In recent years, much attention has been given to the synthesis of optically active nitrogen-containing compounds, with the key step being the highly stereoselective nucleophilic addition of ketene silyl acetals to nitrones (Scheme 2.174). Similar to nitrone cyanations, in ketene silyl acetal reactions one observes an accelerating effect with thiourea derivatives (633). 

Nitrogen compounds are also effective as nucleophiles in the anodic oxidation of silyl-substituted ethers. The electrochemical oxidation in the presence of a carbamate or a sulfonamide in dry THF or dichloromethane results in the selective cleavage of the C-Si bond and the introduction of the nitrogen nucleophile at the carbon (Scheme 21) [55]. Since a-methoxycarbamates are useful intermediates in the synthesis of nitrogen-containing compounds [44], this reaction provides useful access to such compounds. Cyclic silyl-substkuted ethers such as 2-silyltetrahydrofurans are also effective for the introduction of nitrogen nucleophiles. The anodic oxidation in the presence of a carbamate or a... 

There are at least two answers to question (i). First, abnormal proteins can arise in cells due to spontaneous denaturation, errors in protein synthesis, errors in post-translational processing, failure of the correct folding of the protein or damage by free radicals. They are then degraded and replaced by newly synthesised proteins. Secondly, turnover helps to maintain concentrations of free amino acids both within cells and in the blood. This is important to satisfy the requirements for synthesis of essential proteins and peptides (e.g. hormones) and some small nitrogen-containing compounds that play key roles in metabolism (see Table 8.4). 

Figure 8.13 The central role of transdeamination in metabolism of amino adds and further metabolism of the oxoacids in the liver. The box contains the reactions for conversion of the amino acids to their respective oxoacids. Processes are as follows (1) digestion of protein in the intestine and absorption of resultant amino acids, (2) degradation of endogenous protein to amino acids (primarily but not exclusively muscle protein), (3) protein synthesis, (4) conversion of amino acid to other nitrogen-containing compounds (see Table 8.4), (5) oxidation to CO2, (6) conversion to glucose via gluconeogenesis, (7) conversion to fat.

The preparation of oximes from olefins is a valuable approach for the synthesis of nitrogen-containing compounds such as amino acids and heterocycles. Okamoto and colleagues have reported that a catalytic reduction-nitrosation of styrenes 31 with ethyl nitrite and tetrahydroborate anion by the use of bis(dimethylglyoximato)cobalt(II) complex afford the corresponding acetophenone oximes 32 (Scheme 23). 

Azides are useful intermediates for synthesis of various nitrogen-containing compounds. They undergo cycloaddition reactions, as will be discussed in Section 6.2,... 

V.J. Manov-Yuvenskii u. B.K. Nefedov, Synthesis of Nitrogen-containing Compounds by the Interaction of Nitro Compounds with Carbon Monoxide, Russ. Chem. Rev. 50, 470 (1981). 

Further Development to Stereoselective Organic Synthesis of Nitrogen-containing Compounds... 

Biochemically, the pantothenate coenzymes are integral in the metabolism of carbohydrates, lipids, and nitrogen-containing compounds (185,186). They participate in the TCA or Krebs cycle, as well as fatty acid, phospholipid, sterol (cholesterol), and heme synthesis. The coenzymes mediate the exchange of 2-carbon (acetyl) and other acyl groups. They can serve as... 

The microwave-assisted chemistry of a variety of aromatic heterocycles has been extended to the synthesis of fused molecules which share, at least, one heteroatom. In this area, the synthesis of nitrogen containing compounds has been actively investigated. All the compounds described below have been prepared in an effort to find compounds with interesting biological activity. 

A review entitled General Methods of Alkaloid Synthesis includes pyrrolidine, pyridine, and Sceletium alkaloids.1 Another summarizes nitrogen-containing compounds in tobacco and tobacco smoke, and includes some pyrroles, pyrrolidines, pyridines, and alkaloids related to nicotine.2... 

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