CHEM 3410 1st Edition Lecture 9Outline of CurrentI. Reactions ReviewII. Oxidizing Side Chains of BenzeneIII. Substituent Effect on Aromatic RingsA. Electron donating vs electron withdrawingB. Induction vs ResonanceOutline of Last LectureI. Reactions of BenzeneA. Friedel-Craft Alkylationi. LimitationsB. Friedel-Craft AcylationCurrent LectureI. Reactions ReviewThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.II. Oxidizing Side Chains of BenzeneIII. Substituent Effects on Aromatic Rings(1) Substituents affect the reactivity of aromatic rings.- Electron donating groups increase benzene reactivity- Electron withdrawing groups decrease benzene reactivityAll electrons are delocalized, so the withdrawing or donating effects spread to ALL carbons in the ring.(2) Substituents direct the placement of additional groups (location- ortho, meta, para)These groups are deemed “directing groups.”-ortho, para directors-meta directors These ortho, meta, and para placements are named relative to the groups already there.A. Electron Withdrawing vs Electron donatingB. Inductive Effects vs Resonance EffectsInductive effects – bond polarity due to electronegativity differences.Resonance Effects –the group can remove electrons from benzene through resonance Resonance withdrawing groups:NO2 will always acts at an electron withdrawing group (EWG). Cyano groups will always be less reactive than benzene!Resonance DonationResonance donation is far more important than inductive withdrawal because, experimentally, the product is more reactive than Benzene.Bromine is more effective as a resonance donor due to its abundant nonbonding electrons. It can also stabilize itself. Substituent More or less reactive than BenzeneReactivity Directing EffectInductive Effect Resonance EffectH N/A N/A N/A N/A N/ACH3 (or anyR group)Slightly more reactive Activating O,P Donating N/aOH, NH2A lot more reactiveActivating O,P Donating DonorF, Cl, Br, I Slightly less reactiveDeactivating O,P Withdrawing DonorNO2, Cyano A lot less reactiveStrongly DeactivatingM (Strongly) Withdrawing(Strongly) WithdrawingCarbonyls A lot less reactiveStronglyDeactivating M (Strongly) Withdrawing(Strongly) WithdrawingImportant Notes:Activating: more reactive than regular benzeneDeactivating: less reactive than regular benzeneOH, NH2are activator s because of resonance donation. That is what also makes them ortho, para directors. The inductive effects on halogens makes them deactivating. All carbonyls are strong deactivators because of the resonance