Devise a synthesis of each of the following compounds using an arene diazonium salt. Notice that arrows always go from high electron density to low electron density. Explain your answer, Bonus Q2: Explain why Annulene pictured below is considered Non Aromatic rather than Antiaromatic. Second, you’re not going to see any unwanted additional substitution reaction nucleophile attacking the aromatic ring and doing the substitution. The ________ ion intermediate that is formed reacts _______ (slowly/quickly) with a __________(electrophile/nucleophile), which is a base, in the _________ (RDS/ elimination) step. Because nitrogen is more electronegative than carbon, the nitrocation is even less stable than the carbocation, because its worse at handling a positive charge. The C-2 intermediate has more resonance forms than the C-3 intermediate, and so is more stable. This is a fun reaction which gives you an aromatic sulfonic Title: Aromatic Synthesis Problems.doc Author: Birdsell Created Date: 1/2/2004 11:49:40 AM Because of this, N-3 is much more basic than N-1. Ch17 Reactions of Aromatic Compounds (landscape).docx Page8. Why Are Halogens Ortho-, Para- Directors yet Deactivators ? Generally, you’ll always want to opt for the former rather than latter mechanism. Need help? What's bad about ortho/para? what we call an Addition-Elimination mechanism. SN1: The SN1 mechanism involves a carbocation intermediate, and both allylic and benzylic carbocations have resonance, which increases the stability of their carbocations, and speeds up the rate of SN1 reaction. Generally useful, 2. Explain your reasoning. Review the different reactions that are encountered when adding groups to aromatic rings when you can no longer force yourself to do more practice problems! Whenever you feel ready, use this quiz/worksheet combo to answer questions on aromatic compound naming. Then check out my Organic Chemistry Course! Acylation also gives you a carbonyl (a ketone in this case). Then adding a strong base like potassium tert-butoxide will do an E2 reaction to form the alkene. -OR is an EDG and an ortho-para director. So for negatively charged species, the arrow starts at the lone pair. Q15.6.1. Is it aromatic? Mg/ether converts bromobenzene to phenyl Grignard (a nucleophile). The carbocation and the "nitrocation" are both very unstable because they only have 6 valence electrons. So pyridine undergoes EAS reactions at C-3. Lewis Structures, Formal Charges, and Resonance, Benzene Side Chain Reactions and the Benzylic Position, Substituted Benzene EAS (EDG and EWG Effects), Mechanism (show a mechanism using curved arrows..), Alcohol Oxidation Reactions (PCC, Jones Reagent), Reactions (predict the product, show the starting material..), Synthesis (show how to prepare X from Y..), Conjugated Dienes and the Allylic Position (Kinetic vs Thermodynamic Control), Amines (Basicity, Hoffman Elimination, Gabriel Amine Synthesis). Ion this By itself, the nitro group is not very useful. 16.E: Chemistry of Benzene: Electrophilic Aromatic Substitution (Exercises) Last updated; Save as PDF Page ID 61721 ; 16.0 Introduction; 16.1 Electrophilic Aromatic Substitution Reactions: Bromination; 16.2 Other Aromatic Substitutions. Determine if each molecule below is Aromatic, Antiaromatic or Non Aromatic. Your email address will not be published. Aromatic compounds are very stable; aromatic starting materials tend to only form products that are also aromatic. Hint: Review the last video in the Aromaticity Tutorial series, Choose the most acidic/basic molecule or ion in each pair as specified below Substituents are named using their original names, like toluene. In 4-bromonitrobenzene, the substituents are at para positions of each other (it is also called para-bromonitrobenzene). Draw a resonance structure for it. Benzene undergoes Friedel-Crafts acylation (an EAS reaction) to form the ketone. Which nitrogen is more basic? the aromaticity in the ring. Choose an answer and hit 'next'. Organic Chemistry Practice Problems at Michigan State University. Let's compare the resonance forms of EAS carbocation intermediates to see why this is the case. 2) Explain why reaction of benzene with Br2/FeBr3 results in the product … English, science, history, and more. What's good about meta? Sulfonation of Benzene Benzene will react with sulfur trioxide, and in the … However, … [Read More...], While the pre-2015 MCAT only tests you on science and verbal, you are still required to perform … [Read More...], Keto Enol Tautomerization or KET, is an organic chemistry reaction in which ketone and enol … [Read More...], Click for additional orgo tutorial videos. The activation or deactivation of the ring can be predicted more or less by the sum of the individual effects of these substituents. This reaction is a nifty method to substitute a synthesis as it destroys the rest of the substituent group. This allows you to further chemically modify the C=O bond to get something else Some textbooks use electrophiles with formal positive charges, such as HO+. For the quiz, these areas will also be covered: Continue learning about aromatic compounds with the lesson named Aromatic Compound Naming: Types & Examples. The allylic alkene gives two products- the 1,2 product, and the 1,4 product. electrophile attacked your aromatic ring and you had the -H as a “leaving group” When you draw mechanisms, you should use whichever convention your textbook uses. nitrogen-containing side group into virtually anything you like. 15.6 Exercises. In EAS reactions benzene attacks a positively charged electrophile, so its not too surprising that the electrophile will want to add at o/p if a EDG is present. This is another “classic” reaction of arenes. Review the first 2 videos in the. We can identify two general behavior categories, as shown in the following table. Up until this point, all substitution reactions we’ve seen Which lone pairs (if any) in each molecule are aromatic and part of the resonating system?