Addition Reactions to Carbonyls and Alkenes

IMFs involved: Hydrogen bonding, hydrophobic, π–π, ion–dipole

Why common: Carbonyl addition (nucleophilic addition) and alkene addition (electrophilic addition) are foundational organic reactions. IMFs pre-associate reactants, activate electrophiles, and control stereoselectivity.

Examples:

• Aldehyde + HCN → cyanohydrin (H-bond activation of C=O)
• Aldol condensation (enolate + carbonyl; H-bonding stabilizes enolate)
• Michael addition (organocatalytic; H-bond activates Michael acceptor)
• Diels–Alder (π–π and hydrophobic pre-association; aqueous acceleration)
• Epoxidation, dihydroxylation, hydroboration (π–π and H-bond pre-organization)

Role of IMFs: H-bond donors (water, thiourea, proline) activate carbonyls; π–π stacking pre-orients diene/dienophile; hydrophobic effect accelerates “on-water” reactions.