Ketones nitrogen derivatives

The neutral nitrogen compounds include tertiary aliphatic nitro compounds and aromatic nitro compounds amides (simple and substituted) nitrogen derivatives of aldehydes and ketones (hydrazones, semicarbazones, etc.) nitriles nitroso, azo, hydrazo and other intermediate reduction products of aromatic nitro compounds. The imides, primary and secondary nitro compounds, oximes and primary sulphonamides are weakly acidic nitrogen compounds. All the above nitrogen compounds and also the secondary sulphonamides, with few... 

Review "Alkylation of Ketones and Aldehydes via Nitrogen Derivatives"... 

J. K. Whitesell and M. A. Whitesell, Alkylation of Ketones and Aldehydes via their Nitrogen Derivatives , Synthesis, 517-536 (1983). 

Whereas isolated imines are relatively unstable and readily undergo hydrolysis to form carbonyl compounds, alkylated imines and imino derivatives are found as stable compounds in a variety of situations. Thus a number of nitrogen derivatives of aldehydes and ketones, such as the oxime, semicarbazone and hydrazone, contain an imino fragment. 

Asymmetric Alkylations. The use of nitrogen derivatives of carbonyl compounds (imines, imides, amides, sultams, oxazo-lines) is often the most efficient procedure for achieving a-alkylations. Chiral auxiliaries bearing heteroatoms in a 1,2-relationship appear to work best, as they have chelation sites for the metal cation. High levels of asymmetric induction can thus be achieved due to the system rigidity. Cyclic ketones have been alkylated via the lithiated enamine formed from L-f-leucine f-butyl ester (eq 1). High enantiomeric excesses and predictability of absolute configuration make this method attractive. 

When pyrrole and pyrroline have one of their CH groups replaced by nitrogen derivatives are obtained known as pyrrazole and p3nrazo-line. Pyrrazoline yields a ketone known as pyrrazolone. 

Enatnines, itnines, hydrazones and oximes represent the common nitrogen derivatives of ketones and aldehydes (Scheme 1). Both hydrazones and oximes were of importance before the availability of modem spectral techniques for the conversion of liquid carbonyl-containing compounds into solid materials that could be correlated with known samples by melting point and mixed melting point methods. While these applications have all but disappeared, these derivatives, as well as enamines and imines, have emerged as important intermediary species in overall transformations that effect substitution a to the original carbonyl group. Much of this work is based on the seminal contributions of Stork. 

Whitesell, J. K., Whitesell, M. A. Alkylation of ketones and aldehydes via their nitrogen derivatives. Synthesis 1983, 517-536. 

It would be a fair summary of the present situation to say that lithium enolates of ketones or esters are now usually preferred to aza-enolates for nucleophilic alkylation, but that lithium derivatives of cyclohexyl or /-butyl imines are preferred for the nucleophilic alkylation of aldehydes. We shall treat lithium enolates later, along with the equally popular silyl enol ethers, but there is one more nitrogen derivative which should come first. 

The functional groups of organic compounds (ketones, amines, nitrogen derivatives, etc.), responsible for absorption in UV/Vis are called chromophores (Table 9.1). A species formed from a carbon skeleton transparent in the near UV on which are attached one or several chromophores constitutes a chromogene. 

Silylation of azaallyllithium reagents derived from hydrazones unlike silylation of enolates seems to occur mainly on cartwn. While chiral (S)-l-amino-2-methoxymethylpyrrolidine (SAMP) aldehyde hydrazones (c/. equation 4) alkylate to a greater extent on nitrogen to form an azaallylsilyl reagent, ketones give predominant C-silylation. In the case of chiral ketone hydrazones derived from (5)-(4), a-silylated ketone hydrazones are produced in these reactions with consistently high ee ( 6%) ... 

For a more complex example of this type of rearrangement (anionic Claisen rearrangement of a tricyclic a-allyloxy ketone) see ref 108. 2-Allyloxy-3-methyl-2-cyclohexenones109 111 and nitrogen derivatives thereof112 rearrange in a different way. 

Directed functionalizations at the a-carbon atom of aldehydes and ketones have been carried out via reactions of their nitrogen derivatives, including aldimines, ketimines, hydrazines, and oximines. The general procedure involves metallation of the nitrogen derivative, subsequent reaction with an electrophile and final conversion of the obtained derivative into the derivative of the starting aldehyde or ketone. The reaction sequence is depicted in the following general scheme ... 

The chemistry of the metallated nitrogen derivatives of aldehydes and ketones has been reviewed by Mukaiyama [4] and Whitesell-Whitesell [5]. 

In this chapter, some procedures with simple aldimines and ketimines are described. They show representative conditions for the metallation of these nitrogen derivatives, their subsequent reactions with a number of electrophiles and the final hydrolytic cleavage of the C=N bond with formation of derivatives of the starting aldehydes or ketones. 

The liver is the major site of amino acid metabolism in the body and the major site of urea synthesis The liver is also the major site of amino acid degradation. Hepatocytes partially oxidize most amino acids, converting the carbon skeleton to glucose, ketone bodies, or CO2. Because ammonia is toxic, the liver converts most of the nitrogen from amino acid degradation to urea, which is excreted in the urine. The nitrogen derived from amino acid catabolism in other tissues is transported to the liver as alanine or glutamine and converted to urea. 

Oxadiazoline Derivatives. The thermal decomposition of A -l,3,4-oxadia-zolin-2-ones has been shown to occur by two parallel first-order pathways (Scheme 38). One gives the appropriate diazomethane and carbon dioxide, the other a ketone, nitrogen, and carbon monoxide. 

Low-valent nitrogen and phosphorus compounds are used to remove hetero atoms from organic compounds. Important examples are the Wolff-Kishner type reduction of ketones to hydrocarbons (R.L. Augustine, 1968 D. Todd, 1948 R.O. Hutchins, 1973B) and Barton s olefin synthesis (p. 35) both using hydrazine derivatives. 

A class of nitrogen containing compounds that was omitted from the section just dis cussed includes mines and their derivatives Immes are formed by the reaction of aide hydes and ketones with ammonia Immes can be reduced to primary amines by catalytic hydrogenation... 

Raw Material and Energy Aspects to Pyridine Manufacture. The majority of pyridine and pyridine derivatives are based on raw materials like aldehydes or ketones. These are petroleum-derived starting materials and their manufacture entails cracking and distillation of alkanes and alkenes, and oxidation of alkanes, alkenes, or alcohols. Ammonia is usually the source of the nitrogen atom in pyridine compounds. Gas-phase synthesis of pyridines requires high temperatures (350—550°C) and is therefore somewhat energy intensive. 

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