Nucleophiles, reactions carbonyls

Diazetidinones carbonyl derivatives nucleophilic reactions, 7, 462 A -1,2-Diazetine, c/s-3,4-diethyl-3,4-dimethyl-decomposition, 7, 456-457, 483 A -1,2-Diazetine, tetrafluoro-thermolysis, 7, 456 A -l,2-Diazetine, tetramethyl-thermolysis, 7, 456 A -1,2-Diazetine, 3,3,4,4-tetramethyl-properties, 7, 483... 

The addition of carbon nucleophile, including organometallic compounds, enolates, or enols, and ylides to carbonyl gro is an important method of formation of carbon-carbon bonds. Such reactions are- ctremely important in synthesis and will be discussed extensively in Part B. Here, we will examine some of the fundamental mechanistic aspects of addition of carbon nucleophiles to carbonyl groups. 

Enolates can also serve as carbon nucleophiles in carbonyl addition reactions. The addition reaction of enolates with carbonyl compounds is of very broad scope and is of great synthetic importance. Essentially all of the enolates considered in Chapter 7 are capable of adding to carbonyl groups. The reaction is known as the generalized aldol addition. 

When a Br nsted base functions catalytically by sharing an electron pair with a proton, it is acting as a general base catalyst, but when it shares the electron with an atom other than the proton it is (by definition) acting as a nucleophile. This other atom (electrophilic site) is usually carbon, but in organic chemistry it might also be, for example, phosphorus or silicon, whereas in inorganic chemistry it could be the central metal ion in a coordination complex. Here we consider nucleophilic reactions at unsaturated carbon, primarily at carbonyl carbon. Nucleophilic reactions of carboxylic acid derivatives have been well studied. These acyl transfer reactions can be represented by... 

Reactions at the carbon-nitrogen double bond of iminium salts are analogous to nucleophilic reactions at the carbonyl group of aldehydes and ketones. This is why free enamines do not react with nucleophilic reagents, whereas their salts can undergo such reactions. 

Ab initio molecular orbital calculations are being used to study the reactions of anionic nucleophiles with carbonyl compounds in the gas phase. A rich variety of energy surfaces is found as shown here for reactions of hydroxide ion with methyl formate and formaldehyde, chloride ion with formyl and acetyl chloride, and fluoride ion with formyl fluoride. Extension of these investigations to determine the influence of solvation on the energy profiles is also underway the statistical mechanics approach is outlined and illustrated by results from Monte Carlo simulations for the addition of hydroxide ion to formaldehyde in water. 

Reactions of Carbon Nucleophiles with Carbonyl Compounds... 

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