Aldehydes chemistry

Kalabokas, P P. Carlier, P. Fresnet, G. Mouvier, and G. Toupance, Field Studies of Aldehyde Chemistry in the Paris Area, Atmos. Environ., 22, 147-155 (1988). 

SUMMARY OF ALDEHYDE CHEMISTRY PREPARATION 1. Aliphatic Aldehydes... 

Table 3 Examples of Chemoselective Ligation by Weak Base-Aldehyde Chemistry ...

Kalabokas P, Carlier P, Fresnet P, et al. 1988. Field studies of aldehyde chemistry in the Paris area. Atmos Environ 22 147-155. 

Aldehyde chemistry has been used to preferentially PEGylate the N-terminus of proteins [64]. These selective methods as well as nonselective PEGylation have been used successfully when native sequences and conformations are amenable to conjugation away from active sites. 

Jiang, H., Nielsen, J. B., Nielsen, M., J0rgensen, K. A. (2007). Organocatalysed asymmetric (3-amination and multicomponent iyn-selective diamination of a, 3-unsaturated aldehydes. Chemistry - A European Journal, 13, 9068-9075. 

The alkali metal tetrahydridoborates are salts those of sodium and potassium are stable in aqueous solution, but yield hydrogen in the presence of a catalyst. They are excellent reducing agents, reducing for example ion(III) to iron(II). and silver ions to the metal their reducing power is used in organic chemistry, for example to reduce aldehydes to alcohols. They can undergo metathetic reactions to produce other borohydrides, for example... 

Hydrazine and its alkylated derivatives are used as rocket fuels in organic chemistry, substituted phenylhydrazines are important in the characterisation of sugars and other compounds, for example aldehydes and ketones containing the carbonyl group C=0. 

This reaction is used in organic chemistry to separate an aldehyde from, for example, an ester. 

Dinur U and A T Hagler 1995. Geometry-Dependent Atomic Charges Methodology and Application to Alkcmes, Aldehydes, Ketones and Amides. Journal of Computational Chemistry 16 154-170. 

Phenylhydrazine on exposure to light slowly darkens and eventually becomes deep red in colour salts of the base share this property but to a lesser degree, the sulphate and acetate (of the common salts) being most stable to light. Phenylhydrazine is largely used in organic chemistry to characterise aldehydes and ketones as their phenyl-hydrazones (pp. 342, 345), and carbohydrates as their osazones (pp. 136-140). It is readily reduced thus in the process of osazone formation some of the phenylhydrazine is reduced to aniline and ammonia. On the... 

Ozonolysis has both synthetic and analytical applications m organic chemistry In synthesis ozonolysis of alkenes provides a method for the preparation of aldehydes and ketones... 

An ability to form carbon-carbon bonds is fundamental to organic synthesis The addition of Grignard reagents to aldehydes and ketones is one of the most frequently used reactions m synthetic organic chemistry Not only does it permit the extension of carbon chains but because the product is an alcohol a wide variety of subsequent func tional group transformations is possible... 

Alcohol synthesis via the reaction of Grignard reagents with carbonyl com pounds (Section 14 6) This is one of the most useful reactions in synthetic organ ic chemistry Grignard reagents react with formaldehyde to yield primary alco hols with aldehydes to give secondary alcohols and with ketones to form terti ary alcohols... 

The next several chapters deal with the chemistry of various oxygen containing func tional groups The interplay of these important classes of compounds—alcohols ethers aldehydes ketones carboxylic acids and derivatives of carboxylic acids— IS fundamental to organic chemistry and biochemistry... 

The mechanisms by which transition metal oxidizing agents convert alcohols to aldehydes and ketones are complicated with respect to their inorganic chemistry The organic chemistry is clearer and one possible mechanism is outlined m Figure 15 4 The... 

The structural features especially the very polar nature of the carbonyl group point clearly to the kind of chemistry we will see for aldehydes and ketones in this chapter The partially positive carbon of C=0 has carbocation character and is electrophilic The planar arrangement of its bonds make this carbon relatively uncrowded and susceptible to attack by nucleophiles Oxygen is partially negative and weakly basic... 

As we 11 see later in this chapter and the next aldehydes and ketones are involved in many of the most used reactions m synthetic organic chemistry Where do aldehydes and ketones come from ... 

Carey Organic Chemistry I 17 Aldehydes and Ketones I Text Fifth Edition Nucleophilic Addition to... 

FIGURE 17 11 Imine formation between the aldehyde function of 11 as retinal and an ammo group of a protein (opsin) is involved in the chemistry of vision The numbering scheme in retinal is specifically developed for carotenes and related compounds... 

The chemistry of the carbonyl group is probably the single most important aspect of organic chemical reactivity Classes of compounds that contain the carbonyl group include many derived from carboxylic acids (acyl chlorides acid anhydrides esters and amides) as well as the two related classes discussed m this chapter aldehydes and ketones... 

In the preceding chapter you learned that nucleophilic addition to the carbonyl group IS one of the fundamental reaction types of organic chemistry In addition to its own reactivity a carbonyl group can affect the chemical properties of aldehydes and ketones m other ways Aldehydes and ketones having at least one hydrogen on a carbon next to the carbonyl are m equilibrium with their enol isomers... 

You have already had considerable experience with carbanionic compounds and their applications in synthetic organic chemistry The first was acetyhde ion m Chapter 9 followed m Chapter 14 by organometallic compounds—Grignard reagents for example—that act as sources of negatively polarized carbon In Chapter 18 you learned that enolate ions—reactive intermediates generated from aldehydes and ketones—are nucleophilic and that this property can be used to advantage as a method for carbon-carbon bond formation... 

Reduction (Section 2 19) Gam in the number of electrons as sociated with an atom In organic chemistry reduction of carbon occurs when a bond between carbon and an atom which IS more electronegative than carbon is replaced by a bond to an atom which is less electronegative than carbon Reductive ami nation (Section 22 10) Method for the prepara tion of amines in which an aldehyde or a ketone is treated with ammonia or an amine under conditions of catalytic hy drogenation... 

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