I. Sulfonation Reaction to KnowII. Reverse SulfonationIII. Friedel Crafts AlkylationIV. Intramolecular Reaction AlkylationI. Correction to Mechanism Intramolecular Reaction AlkylationII. Other Sources of Suitable Carbocation in Friedel Crafts AlkylationIII. Limitations of Friedel Crafts Alkylation ReactionsIV. Friedel Crafts AcylationI. Correction to Mechanism Intramolecular Reaction Alkylationa. A correction in regards to the placement of the carbocation was made and the lecture handout is located on Course Webb. Important note: Make sure you draw the Hydrogens that are directly bonded to the nucleophilic C (the one that attacks the electrophilic C)II. Other Sources of Suitable Carbocation in Friedel Crafts Alkylationa. As long as the carbocation is suitable to be an electrophile, benzene does not care where the carbocation came from. There are other ways to make carbocation electrophiles from Friedel Crafts reaction:i. For example: Alkylation can occur via the following process:1. Benzene + di-substituted alkene IN H2SO4  benzene w/ t-butyl substituent. (Written out mechanism below)a. Question may be asking you to write the mechanistic explanation for an observed reaction. If you realize that benzene has a new C – C bond, then you automatically must think about Friedel Crafts, but in order for this reaction to happen in the first place, an electrophile must have been present. So think: HOW DO I MAKE MY ELECTROPHILE given the reagents?2. The electrophile in THIS example, comes from pi electrons of the di-substituted attacking an H from sulfuric acid, causing de-protonation of sulfuric acid and forming a secondary carbocation (and –OSO3H)3. Pi electrons from BENZENE now attack the carbocation, and –OSO3H de-protonates the H to reform aromatic benzene with T-butyl substituentb. Know that BF3 is a GOOD LEWIS ACID (electron pair donor)i. If you need to make an electrophile using BF3 and in the presence of an R-OH group, the electrons of O will attack B, forming three bonds on O (positive charge) making a GOOD LEAVING GROUP, and THEN carbocation electrophile forms for benzene’s pi electrons to attackIII. Limitations of Friedel Crafts Alkylation Reactionsa. Re-arrangement limitations:i. Electrophiles become the most stable they could be!1. If Hydride shift is possible to go from secondary to tertiary carbocation, then it will happen.a. From this, you have MAJOR versus minor products.2. T-butyl carbocation possesses the maximum stability for carbocaitonii. Re-arrangement can happen in NOT FREE carbocations1. As you have seen in intramolecular reactions (refer to previous lecture for mechanism)b. Over-alkylation limitations:i. It is very difficult to stop a mono-alkylation reaction. You CANNOT effectively do this reaction with just stoichiometric amounts of a catalyst, therefore we use something like a Lewis acid (such as hydronium) to isolate mono-alkylated or mono-acylated products1. Example: Benzene + secondary carbocation  benzene with many t-butyl substituentsIV. Friedel Crafts Acylationa. Benzene + acyl chloride (generic acid chloride) in AlCl3  KETONEi. For this reaction, you do not worry about rearrangement AND over-acylation problemii. The carbonyl oxygen is electron withdrawing, so when you refer to your memorization sheet (green handout), you will see that this is the case.iii. The effect of it being electron withdrawing is that it DIMINISHES NUCLEOPHILIC ABILITY; therefore you can isolate the product as mono-acylated.1. Now benzene is the fastest nucleophile to attack any electrophile, when before it was not benzene but instead a benzene with an electron donating group (which INCREASES NUCLEOPHILIC ABILITY)b. The Mechanism:i. Step 1 is always to MAKE THE ELECTROPHILE:1. NOT PRODUCTIVE: Electrons on carbonyl O attack Al in AlCl3, giving O a positive charge. This is incorrect because the AlCl3 will just dissociate from the carbonyl O.2. PRODUCTIVE: electrons on the Cl attack Al in AlCl3, followed by an electron pushing mechanism resulting in the ACYLINIUM ION:3. It is resonance stabilized; you have made your electrophileii. Step 2: Do EAS (Electrophilic Aromatic Substitution)1. Benzene pi electrons attack partial positive C in acylinium ion, electrons from triple bond kicked onto O, becomes a carbonyl O again. Carbocation forms, however.2. - Cl-AlCl3 is in solution and can act as a base to de-protonate the H, and electrons left behind reform pi bond, re-aromatization occurs.3. Products: ketone + H-Cl + AlCl3iii. Complication: ketone product’s lone pairs are the most basic in the reaction vessel. Once you make the ketone, it can’t help but start interacting with AlCl3, therefore you need a STROIC QUANTITY of AlCl31. AlCl3 prefers Lewis acid Oxygen (such as the carbonyl O on the phenyl), so to stop this from happening (the “love affair” between AlCl3 and carbonyl O) you must use a stoichiometric quantity of AlCl3a. If you add hydronium ion (Lewis acid), you assist in breaking up the “love affair”CHEM 0320 1st Edition Lecture 9 Outline of Last Lecture I. Sulfonation Reaction to Know II. Reverse Sulfonation III. Friedel Crafts Alkylation IV. Intramolecular Reaction Alkylation Outline of Current Lecture I. Correction to Mechanism Intramolecular Reaction Alkylation II. Other Sources of Suitable Carbocation in Friedel Crafts AlkylationIII. Limitations of Friedel Crafts Alkylation Reactions IV. Friedel Crafts Acylation Current LectureThese 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.I. Correction to Mechanism Intramolecular Reaction Alkylation a. A correction in regards to the placement of the carbocation was made and the lecture handout is located on Course Web b. Important note: Make sure you draw the Hydrogens that are directly bonded to the nucleophilic C (the one that attacks the electrophilic C) II. Other Sources of Suitable Carbocation in Friedel Crafts Alkylationa. As long as the carbocation is suitable to be an electrophile, benzene does not care where the carbocation came from. There are other ways to make carbocation electrophiles from Friedel Crafts reaction: i. For example: Alkylation can occur via the following process: 1. Benzene + di-substituted alkene IN H2SO4  benzene w/ t-butyl substituent. (Written out mechanism below)a. Question may be asking you to write the mechanistic explanation for an observed reaction. If you