A density functional theory study on π-nucleophilicity and electron-transfer oxidation of silyl enol ethers and ketene silyl acetals

Conceptual density functional theory based reactivity descriptors are used to study nucleophilic reactivity of silyl enol ethers and ketene silyl acetals having substituents of both electron releasing and electron withdrawing nature at various key positions of the molecules. While intramolecular reactivity towards electrophilic attack is studied on the basis of local softness (sk-) and local nucleophilicity index (Nk), intermolecular reactivity is assessed using group softness (sg-) and group nucleophilicity (Ng). Ionization potential, inner sphere reorganization energy and structural changes associated with single electron-transfer oxidation for the selected trimethylsilyl enolates have been evaluated. Role of β-methyl substituents are found to be crucial for both nucleophilic reactivity and single electron-transfer oxidation of these systems.