Curtin-Hammett principle thermodynamics

Basic Mechanistic Concepts Kinetic versus Thermodynamic Control, Hammond s Postulate, the Curtin-Hammett Principle... 

SECTION 4.4. BASIC MECHANISTIC CONCEPTS KINETIC VERSUS THERMODYNAMIC CONTROL, HAMMOND S POSTULATE. THE CURTIN-HAMMETT PRINCIPLE... 

However, if both diastereomers are in equilibrium, besides a preferred binding control"2, the higher reactivity of one of the diastereomeric primary substrate complexes (containing the chiral auxiliary ligand) might be responsible for stereocontrol of the overall reaction. According to the Curtin-Hammett principle, the more active primary complex does not necessarily have to be identical with the thermodynamically favored substrate complex in the equilibrium3. 

The terms kinetic control and thermodynamic control are concerned with the manner in which the ratios of products of a reaction are determined. When a reaction is under kinetic control, the ratio of two or more products is determined by the relative energies of the transition states leading to these products. The relative stabilities of the products do not matter. Under thermodynamic control, the ratio of the products is determined solely by the relative energies of the products. In this case the energies of the pathways leading to the products do not matter. In our discussion of the Curtin-Hammett principle, we only analyzed the energies of the transition states and not the energies of the products, and thus this principle applies to kinetic control. Thermodynamic control, which ultimately produces the equilibrium (thermodynamic) mixture of products, can only be achieved when it is possible for the products to interconvert (equilibrate) under the reaction conditions. The simplest way for the... 

Using the Curtin-Hammett Principle to Predict the Stereochemistry of an Addition Reaction 379 Applying the Principle of Microscopic Reversibility to Phosphate Ester Chemistry 380 Kinetic vs. Thermodynamic Enolates 382 Molecularity vs. Mechanism. Cyclization Reactions and Effective Mol a ri ty 384... 

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