Micheal addition

In recent years, the importance of aliphatic nitro compounds has greatly increased, due to the discovery of new selective transformations. These topics are discussed in the following chapters Stereoselective Henry reaction (chapter 3.3), Asymmetric Micheal additions (chapter 4.4), use of nitroalkenes as heterodienes in tandem [4+2]/[3+2] cycloadditions (chapter 8) and radical denitration (chapter 7.2). These reactions discovered in recent years constitute important tools in organic synthesis. They are discussed in more detail than the conventional reactions such as the Nef reaction, reduction to amines, synthesis of nitro sugars, alkylation and acylation (chapter 5). Concerning aromatic nitro chemistry, the preparation of substituted aromatic compounds via the SNAr reaction and nucleophilic aromatic substitution of hydrogen (VNS) are discussed (chapter 9). Preparation of heterocycles such as indoles, are covered (chapter 10). 

FIGURE 10. The torsional potential (relative energies) around the N... C bond in the two model transition state structures, 98a and 99a, for the neutral Micheal addition... 

Keywords Catalysis, dendrimer, dendritic Jeffamines, Micheal addition, PAMAM... 

The presence of adequately placed double bonds allows intramolecular Micheal additions to play an important role in carbocyclic ring formations. 

Diastereoselective reactions of enolates that are derived from a carbonyl compound with a chiral carbon skeleton constitute the earliest concept that provided stereochemical control in enolate chemistry in the classical transformations like alkylation, aldol reaction, and Micheal additions. Beginning with stereocontrol... 

In conjugate additions of strong nucleophiles to a,P-unsaturated carbonyl compounds, the chiral auxiliary can be bound to the acceptor or the donor, and several procedures following both concepts have been developed. As outlined in Section 2.2, enolates are involved in two different roles as intermediates that result from the conjugate addition to the a,P-unsaturated carbonyl compound and as nucleophilic reagents in Micheal additions. 

Micheal, S.I. et al.. Addition of a short peptide Kgand to the adenovirus fiber protein. Gene Ther., 2,660,1995. 

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