The development of paradigms for diastereoselective control in electrophilic attack on trigonal carbon adjacent to a chiral centre, especially for the alkylation and protonation of enolate anions and equivalents, generated from nucleophilic conjugative additions of α,β-unsaturated carbonyl compounds, and nitrates yielded from nucleophilic additions of nitroolefins, is introduced and reviewed. The diastereoselectivity in the kinetic protonation of conformationally restricted cyclic or allenic enol and enolate derivatives can be rationalized by Zimmerman's early transition state model, which is considered to be governed by steric factors exculsively. When acyclic substrates bearing conformational flexibility are employed, Houk's argument which is based on ab initio MO calculation has placed great importance on the approach angle, acute or obtuse which determines the sense of the diastereoselectivity. Subsequently, Fleming's successive refinements incline to avoid destabilizing allylic 1,3-interactions in the reaction of enolate anions with electrophiles. Excepting rationally tuning A-1,3 strain, electronegative heteroatom substituents are considered to occupy an antiperiplanar position to the forming σ bond via the stereoelectronic interaction in Mohrig's general rule for controlling the diastereoselectivity of electrophilic attack on enolate anions.

Contents
1 Introduction
2 Zimmerman model
2.1 Intermolecular kinetic protonation of restricted cyclic enolate derivatives
2.2 Intramolecular kinetic protonation transfer by the proximate groups of cyclic enolate derivatives
2.3 Kinetic protonation of allenic enolate derivatives
2.4 Application of Zimmerman model in open-chain substrates
3 Houk's arguments model
4 Fleming's refinements for Houk model
4.1 Fleming's model governed by steric factors
4.2 Fleming's model governed by heteroatom-containing substituents on the chiral carbon atom
5 Mohrig model and the applications
5.1 Introduction to Mohrig model
5.2 Applications of Mohrig model
5.3 Stereoelectronic effect in the protonation of chelate-controlled cyclic nitronate anions
6 Conclusions and prospects