Lecture Notes Chem 51B S. King. Chapter 18 Electrophilic Aromatic Substitution

Size: px
Start display at page:

Download "Lecture Notes Chem 51B S. King. Chapter 18 Electrophilic Aromatic Substitution"

Transcription

1 Lecture otes Chem 51B S. King Chapter 18 Electrophilic Aromatic Substitution I. Electrophilic Aromatic Substitution The most characteristic reaction of aromatic compounds is electrophilic aromatic substitution, in which one of the ring hydrogens is substituted by a halogen, nitro group, sulfonic acid group, alkyl or acyl group. Br 2 FeBr 3 Bromination 3 2 S 4 itration S 3 2 S 4 Sulfonation RBr AlCl 3 Friedel-Crafts Alkylation RCCl AlCl 3 Friedel-Crafts Acylation A. Chlorination & Bromination of Benzene Recall: + Br 2 143

2 With aromatic systems, Electrophilic Addition does not take place: + Br 2 If a catalyst and heat is used, Electrophilic Aromatic Substitution occurs: + Br 2 FeBr 3 Mechanism: Step 1: Make Electrophile Step 2: Benzene attacks electrophile to make a resonance-stabilized carbocation Step 3: Regenerate Aromatic Ring 144

3 Energy diagram: TS1 TS2 E a 2 energy E a 1!+ Br!+!+ Br B. itration of Benzene Reaction coordinate Benzene reacts with hot concentrated nitric acid and sulfuric acid to yield nitrobenzene:! S 4 In this reaction the electrophile is nitronium ion, which is created by protonation of 3 by the strong acid sulfuric acid, followed by loss of 2. Mechanism: Step 1: Make electrophile Step 2: Benzene attacks 145

4 Step 3: Regenerate Aromatic Ring C. Sulfonation of Benzene Benzene reacts with concentrated sulfuric acid or fuming sulfuric acid to produce benzenesulfonic acid. Mechanism: Step 1: Make electrophile 25 C conc. 2 S 4 or fuming sulfuric acid: S + 2 S 4 Step 2, 3: Benzene Attacks & Then Regenerate Aromatic Ring An interesting thing about aromatic sulfonic acids: Formation of an aromatic sulfonic acid is reversible, and can be driven in either direction! + 2 S 4 S

5 II. Aromatic Substitution with Carbocations as Electrophiles When carbon is cationic, it can also be an electrophile in aromatic substitution reactions. A. Friedel-Crafts Alkylation + R Cl Mechanism: Step 1: Make electrophile Step 2,3: Benzene Attacks & Regenerate Aromatic Ring 147

6 The carbocationic electrophile can also be formed by protonation of an alkene: + 2 S 4 The carbocationic electrophile can also be formed by starting with an alcohol: + 2 S 4 Big Problem: Carbocations like to rearrange! Like other reactions involving carbocations, the Friedel-Crafts alkylation is susceptible to carbocationic rearrangement. C 3 C 2 C 2 Cl AlCl 3 Mechanism for carbocation rearrangement: 148

7 B. Friedel-Crafts Acylation Acid chlorides and acid anhydrides also serve as sources of electrophiles for Friedel-Crafts reactions. + 3 C or Cl 1. AlCl Mechanism: 3 C C 3 149

8 III. Substituent Effects in Electrophilic Aromatic Substitution + 3 compare with: A group that is already present on a benzene ring may make it easier or harder to introduce new substituents, and can direct where the new substituents will go. A. Ring Activating: A group that makes it easier to introduce new substituents is ring activating. Ring activating substituents are ELECTR DATIG. > R 2 > > R > C R > C R > R > Ar R 2 B. Ring Deactivating: A group that makes it harder to introduce a second substituent is ring deactivating. Ring deactivating substituents are ELECTR WITDRAWIG. 2! R 3 > CF 3 > CCl 3 > S 3 > C > C R R 2 2 R 3 ketone, aldehydes amides, esters, carboxylic acids 150

9 Rule 1: Ring activating substituents direct incoming substituents into the o,p- positions. They are ortho, para directing. > R 2 > > R > C R > C R > R > Ar R 2 Reasoning: An electron donating group stabilizes the cationic intermediate only when it is ortho or para to the site of substitution. the resonance structures: 151

10 Rule 2: Ring deactivating substituents direct incoming substituents into the m -position. They are meta directing. 2! R 3 > CF 3 > CCl 3 > S 3 > C > C R R 2 2 R 3 Reasoning: The meta position is the least destabilized. the resonance structures: ketone, aldehydes amides, esters, carboxylic acids 152

11 Rule 3: alogens are slightly deactivating but ortho, para directing. With halogens, there is a strong inductive effect: & a weak resonance effect: Br Br Br C. Effect of Sterics and More than ne Substituent: 1. With o, p -directors, para will predominate as substituents and incoming reagents get larger: C 3 C(C 3 ) 2 153

12 2. When the directing effects of two or more substituents conflict, the one that is strongly activating and o,p- directing determines the orientation of the new substituent. C 3 2 S 3 2 S 4 IV. Additional Considerations Regarding Substituent Effects A. Methoxy, ydroxy, and Amine Substituents Methoxy, hydroxy, and amine substituents are so strongly activating that halogenation is carried out without the Lewis acid catalyst (FeBr 3 or FeCl 3 ). Even without a catalyst, multiple halogenation is observed. Br 2 2 Solution: To monohalogenate phenol, run the reaction in a nonpolar solvent such as CCl 4 without added catalyst: Br 2 CCl 4 154

13 Amine substituents give multiple halogenation even at low temperature without added catalyst: 2 Br 2 0 C Solution: Acylate the amine. This turns the ring from strongly activated to moderately activated and allows monohalogenation: 2 C 3 CCl Br 2 pyridine FeBr 3 (Ch. 22 chemistry) , 2 2. a (Ch. 22 chemistry) Q. ow is the amine converted into an amide? A. An addition/elimination reaction, with a mechanism similar to the mechanism thionyl chloride reacting with an alcohol. 155

14 B. Friedel-Crafts Alkylation & Acylation 1. In the Friedel-Crafts alkylation reaction, overalkylation is a problem! (the product is more reactive than the starting material - must use large excess benzene to avoid). C 3 C 2 Cl AlCl 3 2. veracylation is not a problem in the Friedel-Crafts acylation reaction. C 3 CCl AlCl 3 3. Deactivated, meta directing benzene derivatives and aniline derivatives give poor yields of Friedel-Crafts products and should not be used in this reaction. (C 3 ) 3 2 C CF 3 S 3 2 Why aniline derivatives?? The amino groups - 2, -R, and R 2 are changed into powerful deactivating groups by the Lewis acids used to catalyze Friedel- Crafts reactions. 156

15 Solution: Acylate the amine. This turns the ring from strongly activated to moderately activated and allows Friedel-Crafts reactions to take place: 2 C 3 CCl pyridine C 3 CCl AlCl , 2 2. a C. itration of Aniline Derivatives Aniline derivatives cannot be nitrated because nitric acid is an oxidizing agent and primary amines are easily oxidized (nitric acid and aniline can be explosive). nly tertiary aromatic amines and acetamide derivatives can be nitrated. Don t do this: S 4 These do work: (C 3 ) 2 CC S S 4 Solution for 1 Amines: Acylate the amine. 2 C 3 CCl pyridine 3 2 S 4 157

16 V. Reactions of Substituents on Benzene We now know how to convert benzene into a variety of substituted benzene derivatives: Br S 3 R 2 C R Benzene rings with other substituents can be made by converting these substituted benzene derivatives into other functional groups using chemistry from chapters 7, 8, 9, 10, 11, 12, 15, 16. A. Reactions of Alkyl Substituents on Benzene Alkyl substituents on benzene can be converted into many other functional groups using reactions we have already talked about. C 2 C 2 CC 3 1. KMn 4 a " C 3 BS RR h! C 2 Br C C C 2 C C C 2 3 C 2 C 2 C 2 C C 2 C C 158

17 Br C 2 C 3 CC 3 (C 3 ) 3 C B. xidation of Alkyl Groups Bonded to Aromatic Rings An alkyl group bonded to a benzene ring can be oxidized to a carboxylic acid. commonly used oxidizing agents are KMn 4 or a 2 Cr 2 7 / 3 +. C 3 C(C 3 ) 2 (C 2 ) 5 C 3 or or 1. KMn 4,! a, C(C 3 ) 3 1. KMn 4,! a, compare with: KMn 4 a, 2 low temp. 159

18 C. Reduction of Substituents Bonded to Benzene A nitro substituent can be reduced used catalytic hydrogenation or by using a metal (tin, iron or zinc) plus Cl. The product is aniline. 2 2 Pd 2 Sn or Zn(g) Cl A ketone or aldehyde can be reduced used Clemmensen or Wolff-Kishner reduction. These reagents do not reduce esters, carboxylic acids, amides or acid chlorides. R C R' R C R' 1. Clemmensen Reduction (Cl, Zn/g): CC 2 C 2 C Cl Zn(g)! 2. Wolff-Kishner Reduction ( 2 2, K): C 3 C C3 a 2 2! Q. Why 2 ways to do the same reduction? A. Sometimes you have acid sensitive or base sensitive groups elsewhere in the molecule. 160

19 Clemmensen Reduction: Wolff-Kishner Reduction: Both methods LY WRK FR ALDEYDES AD KETES!!!! You cannot use these methods with esters or other carboxylic acid derivatives!!!! VI. ucleophilic Aromatic Substitution via Addition/Elimination Aromatic rings do not react easily with nucleophiles. ucleophiles can displace aryl halides in highly deactivated benzene derivatives via an addition/elimination mechanism. Cl 2 a 100 C 2 Characteristics of Reaction: Strong nucleophile required. Reaction cannot proceed by S 1 (formation of an aryl cation) because the EWG would destabilize this intermediate. Reaction cannot proceed by S 2: Like vinyl halides, aryl halides cannot achieve the correct geometry for backside displacement (aromatic ring blocks approach of the nucleophile to the back of the carbon bearing the L.G 161

20 Fluoride is a much better L.G. than iodide ion in this reaction. Mechanism: Addition Elimination: F Q. Why is fluoro a better L.G. in this reaction? A. Two reasons: 162

21 1. F is more electronegative than I. 2. F is much smaller there is less steric hindrance to the approaching nucleophile that will bond to carbon and give a tetrahedral intermediate. VI. Synthetic Applications of Electrophilic Aromatic Substitution When planning a synthesis involving Electrophilic Aromatic Substitution, a couple of things need to be kept in mind: 1. Careful attention must be paid to the order in which the reactions are carried out! Example: Synthesize the following compound from benzene: C(C 3 )

22 2. Functional group manipulation can convert substituents on benzene into other functional groups that have the desired directing properties. Example: Synthesize the following compound from benzene: C 2 C 2 C

23 3. The sulfonyl group can be used as a blocking or directing group, which can be easily removed once it has served its purpose. Example: Synthesize the following compound from benzene: C(C 3 ) 2 2 To add multiple 2 groups to the ring, use more 3, 2 S 4, and increase Δ! Q: Why is extra heat needed? A: Example: C S 4! 165

24 4. Consider multiple pathways when more complicated syntheses are desired. Example: Synthesize the following compound from benzene: 3 C 2 166

Reaction Coordinate Diagrams for the Two Benzene Reactions

Reaction Coordinate Diagrams for the Two Benzene Reactions Electrophilic Addition vs. Substitution ( LEAVES!) Electrophilic Aromatic Substitution δ δ E E Y Y Reaction Coordinate Diagrams for the Two Benzene Reactions δ δ E E Y Y Electrophilic aromatic substitutions

More information

Electrophilic Aromatic Substitution

Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution Electrophilic substitution is the typical reaction type for aromatic rings. Generalized electrophilic aromatic substitution: E E Electrophile Lewis acid: may be or neutral.

More information

Electrophilic Aromatic Substitution Reactions

Electrophilic Aromatic Substitution Reactions Electrophilic Aromatic Substitution Reactions, Course Notes Archive, 1 Electrophilic Aromatic Substitution Reactions An organic reaction in which an electrophile substitutes a hydrogen atom in an aromatic

More information

Chapter 16: Chemistry of Benzene: Electrophilic Aromatic Substitution. Let us look at bromination: δ+ δ Br Br FeBr 3 Br Br FeBr 3

Chapter 16: Chemistry of Benzene: Electrophilic Aromatic Substitution. Let us look at bromination: δ+ δ Br Br FeBr 3 Br Br FeBr 3 Chapter 16: Chemistry of Benzene: lectrophilic Aromatic Substitution lectrophilic positively charged species searching for electron density Aromatic benzene ring with a high electron density Substitution

More information

Benzene Benzene is best represented as a resonance hybrid:

Benzene Benzene is best represented as a resonance hybrid: Electrophilic Aromatic Substitution (EAS) is a substitution reaction usually involving the benzene ring; more specifically it is a reaction in which the hydrogen atom of an aromatic ring is replaced as

More information

Electrophilic Aromatic Substitution

Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution: a reaction in which the hydrogen atom of an aromatic ring is replaced as a result of an electrophilic attack on the aromatic ring

More information

CHEM 211 CHAPTER 16 - Homework

CHEM 211 CHAPTER 16 - Homework CHEM 211 CHAPTER 16 - Homework SHORT ANSWER Consider the Friedel-Crafts alkylation reaction below to answer the following question(s): 1. Refer to the reaction above. Draw the structure of the electrophilic

More information

CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway. CHAPTER 14 Substitution Reactions of Aromatic Compounds

CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway. CHAPTER 14 Substitution Reactions of Aromatic Compounds CHEM 322 Organic Chemistry II - Professor Kathleen V. Kilway "Organic Chemistry" by Maitland Jones, 4 th edition Chapter 14 Homework: 1, 2, 5, 7, 13, 19, 20, 23, 26, 27, 28, 30, 31, 34, 35, 36, 41, 46,

More information

REACTIONS OF AROMATIC COMPOUNDS

REACTIONS OF AROMATIC COMPOUNDS A STUDENT SHOULD BE ABLE TO: REACTIONS OF AROMATIC COMPOUNDS 1. Predict the product(s) of Electrophilic Aromatic Substitution (EAS), Nucleophilic Aromatic Substitution (S N Ar) and Elimination-Addition

More information

4/18/2011. 9.8 Substituent Effects in Electrophilic Substitutions. Substituent Effects in Electrophilic Substitutions

4/18/2011. 9.8 Substituent Effects in Electrophilic Substitutions. Substituent Effects in Electrophilic Substitutions 9.8 Substituent effects in the electrophilic substitution of an aromatic ring Substituents affect the reactivity of the aromatic ring Some substituents activate the ring, making it more reactive than benzene

More information

Benzene and aromatic compounds (McMurry Ch. 15 & 16) The resonance hybrid model explains these properties of benzene:

Benzene and aromatic compounds (McMurry Ch. 15 & 16) The resonance hybrid model explains these properties of benzene: Benzene and aromatic compounds (McMurry Ch. 15 & 16) C 6 H 6 is an unusually stable molecule that does NOT react like alkenes do A model was proposed by Kekule in 1865: The resonance hybrid model explains

More information

Aromaticity and Reactions of Benzene

Aromaticity and Reactions of Benzene Aromaticity and eactions of Benzene ark College Benzene is a unique molecule it is highly unsaturated with 6 carbons and 6 hydrogens, it is planar, and has a high degree of symmetry. These features explain

More information

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids.

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. R Carboxylic acids are classified according to the substituent

More information

Q.1 Draw out some suitable structures which fit the molecular formula C 6 H 6

Q.1 Draw out some suitable structures which fit the molecular formula C 6 H 6 Aromatic compounds GE 1 BENZENE Structure Primary analysis revealed benzene had an... empirical formula of and a molecular formula of 6 6 Q.1 Draw out some suitable structures which fit the molecular formula

More information

Carboxylic Acid Derivatives and Nitriles

Carboxylic Acid Derivatives and Nitriles Carboxylic Acid Derivatives and itriles Carboxylic Acid Derivatives: There are really only four things to worry about under this heading; acid chlorides, anhydrides, esters and amides. We ll start with

More information

Protonation. favored H 3 O + R O O H

Protonation. favored H 3 O + R O O H arboxylic Acids arboxylic acids have one property that distinguishes them from most other organic compounds they re acidic. Now not as acidic as fuming sulfuric acid, but still pretty darned acidic. The

More information

Electrophilic Addition Reactions

Electrophilic Addition Reactions Electrophilic Addition Reactions Electrophilic addition reactions are an important class of reactions that allow the interconversion of C=C and C C into a range of important functional groups. Conceptually,

More information

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens).

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens). Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. Normally: Oxidation

More information

Under acidic conditions, carbonyl compounds are protonated on O first, then weak base deprotonates at the α-c to give enol.

Under acidic conditions, carbonyl compounds are protonated on O first, then weak base deprotonates at the α-c to give enol. Substitution reactions of carbonyl compounds at the α-position Carbonyl compounds are acidic at α-c (e.g. C 2 C ); this is because of the electrophilic nature of carbonyl C= bond. The pka values of simple

More information

Chemistry Notes for class 12 Chapter 13 Amines

Chemistry Notes for class 12 Chapter 13 Amines 1 P a g e Chemistry Notes for class 12 Chapter 13 Amines Amines constitute an important class of organic compounds derived by replacing one or more hydrogen atoms ofnh 3 molecule by alkyl/aryl group(s).

More information

13.1 Alcohols and Phenols. Nomenclature. Nomenclature. Nomenclature. Alcohols possess a hydroxyl group ( OH). Hydroxyl groups in natural compounds.

13.1 Alcohols and Phenols. Nomenclature. Nomenclature. Nomenclature. Alcohols possess a hydroxyl group ( OH). Hydroxyl groups in natural compounds. 13.1 Alcohols and Phenols Alcohols possess a hydroxyl group ( OH). 13.1 Alcohols and Phenols Hydroxyl groups in natural compounds. Hydroxyl groups are extremely common in natural compounds. 13-1 13-2 13.1

More information

Organic Chemistry Specific Name Reactions

Organic Chemistry Specific Name Reactions Organic Chemistry Specific Name Reactions Sandmeyer Reaction Class XII The Cl, Br and CN nucleophiles can easily be introduced in the benzene ring of benzene diazonium salt in the presence of Cu(I) ion.

More information

C 2 H 5 L L LC 2 H 5 l max = 256 nm (e = 20,000) 283 nm (e = 5,100) CH 3 H 3 C. CH 3 i. B bimesityl l max = 266 nm (e = 700)

C 2 H 5 L L LC 2 H 5 l max = 256 nm (e = 20,000) 283 nm (e = 5,100) CH 3 H 3 C. CH 3 i. B bimesityl l max = 266 nm (e = 700) 750 CAPTER 6 TE CEITRY F BENZENE AND IT DERIVATIVE This hybridization allows one of its electron pairs to occupy a 2p orbital, which has the same size, shape, and orientation as the carbon 2p orbitals

More information

Chapter 13 Alkenes and Alkynes

Chapter 13 Alkenes and Alkynes hapter 13 Alkenes and Alkynes Types of Bonds Alkanes and haloalkanes consist of atoms held together by bonds. These can also be called sigma bonds (σ bonds) which means that the orbitals of each atom overlap

More information

ammonium salt (acidic)

ammonium salt (acidic) Chem 360 Jasperse Ch. 19 otes. Amines 1 eactions of Amines 1. eaction as a proton base (Section 19-5 and 19-6) amine base -X (proton acid) a X ammonium salt (acidic) Mechanism: equired (protonation) everse

More information

Ozonolysis of Alkenes

Ozonolysis of Alkenes zonolysis of Alkenes 1 When 2-methyl-2-pentene reacts with ozone, the initial 1,2,3-trioxolane product is 144, but this rearranges to ozonide 145. If 145 is treated with hydrogen peroxide as above, one

More information

Reminder: These notes are meant to supplement, not replace, the textbook and lab manual. Electrophilic Aromatic Substitution notes

Reminder: These notes are meant to supplement, not replace, the textbook and lab manual. Electrophilic Aromatic Substitution notes Reminder: These notes are meant to supplement, not replace, the textbook and lab manual. Electrophilic Aromatic Substitution notes History and Application: The rate of a reaction directly impacts the commercial

More information

Reaction 2. Radical addition of hydrogen bromide (HBr) to alkenes. (NOT COVERED THIS TIME)

Reaction 2. Radical addition of hydrogen bromide (HBr) to alkenes. (NOT COVERED THIS TIME) http://courses.chem.psu.edu/chem38/reactions/reactions.html Reaction 1. Electrophilic addition of hydrogen halides (HX) to alkenes. HCl, HBr in ether KI + H 3 PO 4 room temperature electrophilic addition

More information

CHAPTER 11 Alcohol Reactivity

CHAPTER 11 Alcohol Reactivity CHAPTER 11 Alcohol Reactivity 1 Summary Table Oxidation: Adding O, Losing H Chromic Acid (Cr(VI)) is a powerful oxidizing agent 4 Oxidation Mechanism When Aldehydes are formed by Cr(VI) in water, they

More information

EXPERIMENT 3 (Organic Chemistry II) Nitration of Aromatic Compounds: Preparation of methyl-m-nitrobenzoate

EXPERIMENT 3 (Organic Chemistry II) Nitration of Aromatic Compounds: Preparation of methyl-m-nitrobenzoate EXPERIMENT 3 (Organic Chemistry II) Nitration of Aromatic Compounds: Preparation of methyl-m-nitrobenzoate Pahlavan/Cherif Purpose a) Study electrophilic aromatic substitution reaction (EAS) b) Study regioselectivity

More information

Alkynes and Their Reactions

Alkynes and Their Reactions Alkynes and Their Reactions Naming Alkynes Alkynes are named in the same general way that alkenes are named. In the IUPAC system, change the ane ending of the parent alkane name to the suffix yne. Choose

More information

Avg. 16.4 / 25 Stnd. Dev. 8.2

Avg. 16.4 / 25 Stnd. Dev. 8.2 QUIZ TREE Avg. 16.4 / 25 Stnd. Dev. 8.2 xidation of Alcohols with Chromium (VI): Jones xidation 2 Alcohols are oxidized by a solution of chromium trioxide in aqueous acetone (2), in the presence of an

More information

Chapter 7 - Alkenes and Alkynes I

Chapter 7 - Alkenes and Alkynes I Andrew Rosen Chapter 7 - Alkenes and Alkynes I 7.1 - Introduction - The simplest member of the alkenes has the common name of ethylene while the simplest member of the alkyne family has the common name

More information

Chapter 22 Carbonyl Alpha-Substitution Reactions

Chapter 22 Carbonyl Alpha-Substitution Reactions John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 22 Carbonyl Alpha-Substitution Reactions The α Position The carbon next to the carbonyl group is designated as being in the α position Electrophilic

More information

ALCOHOLS: Properties & Preparation

ALCOHOLS: Properties & Preparation ALLS: Properties & Preparation General formula: R-, where R is alkyl or substitued alkyl. Ar-: phenol - different properties. Nomenclature 1. ommon names: Name of alkyl group, followed by word alcohol.

More information

Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group

Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group Organic Chemistry II / CHEM 252 Chapter 16 Aldehydes and Ketones I. Nucleophilic Addition to the Carbonyl Group Bela Torok Department of Chemistry University of Massachusetts Boston Boston, MA 1 Nomenclature

More information

Acids and Bases: Molecular Structure and Acidity

Acids and Bases: Molecular Structure and Acidity Acids and Bases: Molecular Structure and Acidity Review the Acids and Bases Vocabulary List as needed. Tutorial Contents A. Introduction B. Resonance C. Atomic Radius D. Electronegativity E. Inductive

More information

Alkynes: An Introduction to Organic Synthesis

Alkynes: An Introduction to Organic Synthesis Alkynes: An Introduction to Organic Synthesis Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature

More information

Determining the Structure of an Organic Compound

Determining the Structure of an Organic Compound Determining the Structure of an Organic Compound The analysis of the outcome of a reaction requires that we know the full structure of the products as well as the reactants In the 19 th and early 20 th

More information

Learning Guide for Chapter 11 - Alkynes

Learning Guide for Chapter 11 - Alkynes Learning Guide for Chapter 11 - Alkynes Introduction to s - p 1 ybridization and geometry, Reactivity, Types of s, Cyclic s, Physical properties, Spectroscopy, Acidity, Natural occurrence and uses Nomenclature

More information

Carboxylic Acid Structure and Chemistry: Part 2

Carboxylic Acid Structure and Chemistry: Part 2 Principles of Drug Action 1, pring 2005, Carboxylic Acids Part 2 Carboxylic Acid tructure and Chemistry: Part 2 Jack Deuiter IV. eactions of the Carboxylic Acid eactions Depending on their overall structure,

More information

SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS

SULFONATE AND INORGANIC ESTER DERIVATIVES OF ALCOHOLS 0. ULFNATE AND INRGANIC ETER DERIVATIVE F ALCL 44 R 2 C L CR 2 carbocation Lewis acid base association X (halide ion) 2 $ R 2 C L CR 2 R R X C A C $ alkyl halide R R alkene $ $ Brønsted acid base reaction

More information

Mass Spec - Fragmentation

Mass Spec - Fragmentation Mass Spec - Fragmentation An extremely useful result of EI ionization in particular is a phenomenon known as fragmentation. The radical cation that is produced when an electron is knocked out of a neutral

More information

Identifying an Unknown Substance using Infrared Spectroscopy (IR), Carbon-13 Nuclear Magnetic Resonance ( 13 C NMR), and Proton Nuclear Magnetic

Identifying an Unknown Substance using Infrared Spectroscopy (IR), Carbon-13 Nuclear Magnetic Resonance ( 13 C NMR), and Proton Nuclear Magnetic Identifying an Unknown Substance using Infrared Spectroscopy (I), arbon-13 Nuclear Magnetic esonance ( 13 NM), and Proton Nuclear Magnetic esonance ( 1 NM) Identifying an Unknown Substance using Infrared

More information

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of Alkynes An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of acetaldehyde, acetic acid, vinyl chloride O O H

More information

Amines H 3 C H. CH 2 CH 3 ethylmethylamine. Nomenclature. 1 o : RNH 2, 2 o : RR'NH, 3 o : RR'R"N, 4 o (salt) RR'R"R'"N + R = alkyl or aryl

Amines H 3 C H. CH 2 CH 3 ethylmethylamine. Nomenclature. 1 o : RNH 2, 2 o : RR'NH, 3 o : RR'RN, 4 o (salt) RR'RR'N + R = alkyl or aryl Amines omenclature 1 o :, 2 o : 'H, 3 o : '", 4 o (salt) '"'" + = alkyl or aryl ommon names For simple amines name groups attached to alphabetically; use suffix -amine. H 3 H H 2 ethylmethylamine In complicated

More information

Nucleophilic Substitution and Elimination

Nucleophilic Substitution and Elimination Nucleophilic Substitution and Elimination What does the term "nucleophilic substitution" imply? A nucleophile is an the electron rich species that will react with an electron poor species A substitution

More information

CHEM 341: Organic Chemistry I

CHEM 341: Organic Chemistry I EM 341: rganic hemistry I at North Dakota tate University Final Exam - tudy Guide Reactions to know ubstitution of Alcohols R X R X N 1 ubstitution - N 2 ubstitution 3 carbocation best 2 carbocation ok

More information

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8

Alkynes: An Introduction to Organic Synthesis. Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes: An Introduction to Organic Synthesis Based on McMurry s Organic Chemistry, 6 th edition, Chapter 8 Alkynes! Hydrocarbons that contain carbon-carbon triple bonds! Acetylene, the simplest alkyne

More information

for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency of the vibration

for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency of the vibration ! = 1 2"c k (m + M) m M wavenumbers! =!/c = 1/" wavelength frequency! units: cm 1 for excitation to occur, there must be an exact match between the frequency of the applied radiation and the frequency

More information

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules

Chapter 25 The Chemistry of Life: Organic Chemistry. 25.1 Some General Characteristics of Organic Molecules Chapter 25 The Chemistry of Life: Organic Chemistry general characteristics of organic molecules introduction to hydrocarbons alkanes unsaturated hydrocarbons functional groups: alcohols and ethers compounds

More information

Benzene benzene aromatic hydrocarbons aromatic not not

Benzene benzene aromatic hydrocarbons aromatic not not Benzene 1 NT 87 90 ompound 87 has the formula 6 6, is known as benzene, and it is a hydrocarbon derived from petroleum distillates. Benzene is the parent compound for a class of compounds known as aromatic

More information

AROMATIC COMPOUNDS A STUDENT SHOULD BE ABLE TO:

AROMATIC COMPOUNDS A STUDENT SHOULD BE ABLE TO: A STUDENT SHULD BE ABLE T: ARMATIC CMPUNDS 1. Name benzene derivatives given the structures, and draw the structures given the names. This includes: Monosubstituted benzenes named as derivatives of benzene:

More information

21.9 REDUCTION OF CARBOXYLIC ACID DERIVATIVES

21.9 REDUCTION OF CARBOXYLIC ACID DERIVATIVES 10 APTER 1 TE EMITRY F ARBXYLI AID DERIVATIVE TUDY GUIDE LIK 1.5 Esters and ucleophiles 1.17 Give the structure of the product in the reaction of each of the following esters with isotopically labeled

More information

Q.1 Draw structures for all amines of molecular formula C 4 H 11 N. Classify them as primary, secondary or tertiary amines.

Q.1 Draw structures for all amines of molecular formula C 4 H 11 N. Classify them as primary, secondary or tertiary amines. 1 AMIES Structure lassification ontain the 2 group. primary (1 ) amines secondary (2 ) amines tertiary (3 ) amines quarternary (4 ) ammonium salts. 1 2 3 4 Aliphatic Aromatic methylamine, ethylamine, dimethylamine

More information

It does not react N.R.

It does not react N.R. Benzene versus yclohexene versus yclohexadiene 1 l l cyclohexene l l cyclohexadiene l Expect this to react similarly "cyclohexatriene" It does not react l N.R. benzene Benzene is resonance stabilized,

More information

So far we have mostly limited our good leaving groups to the very similar, stable halide anions, Cl -, Br - and I -.

So far we have mostly limited our good leaving groups to the very similar, stable halide anions, Cl -, Br - and I -. Extending the - pectrum: Making Alcohols () into eactive and E eactants (Two Ways) o far we have mostly limited our good leaving groups to the very similar, stable halide anions, -, Br - and I -. 1 Base

More information

Writing a Correct Mechanism

Writing a Correct Mechanism Chapter 2 1) Balancing Equations Writing a Correct Mechanism 2) Using Arrows to show Electron Movement 3) Mechanisms in Acidic and Basic Media 4) Electron rich Species: Nucleophile or Base? 5) Trimolecular

More information

Typical Infrared Absorption Frequencies. Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment

Typical Infrared Absorption Frequencies. Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment Typical Infrared Absorption Frequencies Functional Class Range (nm) Intensity Assignment Range (nm) Intensity Assignment Alkanes 2850-3000 CH 3, CH 2 & CH 2 or 3 bands Alkenes 3020-3100 1630-1680 1900-2000

More information

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes

Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes Study Guide Chapters 19-20 Alkanes, Alkenes and Alkynes 1) Carbon-Carbon Bonding in Alkanes (C-C), Alkenes (C=C) and Alkynes (C C). Understand the hybridization of atomic orbitals (ground state promotion

More information

Chapter 18. Reactions of Aldehydes and Ketones

Chapter 18. Reactions of Aldehydes and Ketones hapter 18. Reactions of 1 Aldehydes and Ketones Reaction of a nucleophile with an aldehyde or ketone gives an alkoxide, and subsequent hydrolysis leads to an alcohol. This chapter will define differences

More information

ALKENES AND ALKYNES REACTIONS A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE ABLE TO:

ALKENES AND ALKYNES REACTIONS A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE ABLE TO: ALKENES AND ALKYNES REACTINS A STUDENT W AS MASTERED TE MATERIAL IN TIS SECTIN SULD BE ABLE T: 1. Given the starting materials and reaction conditions, predict the products of the following reactions of

More information

IDENTIFYING STUDENTS MISCONCEPTIONS IN A-LEVEL ORGANIC CHEMISTRY

IDENTIFYING STUDENTS MISCONCEPTIONS IN A-LEVEL ORGANIC CHEMISTRY IDENTIFYING STUDENTS MISCONCEPTIONS IN A-LEVEL ORGANIC CHEMISTRY Lim Choon Huat Bryan Innova Junior College Abstract In recent years, research in science education has been focused on identifying and addressing

More information

Chapter 8: Chemistry of Alkynes (C n H 2n-2 )

Chapter 8: Chemistry of Alkynes (C n H 2n-2 ) hapter 8: hemistry of Alkynes ( n 2n-2 ) Bonding & hybridization Both are sp-hybridized Bond angles = 180 o 1 σ + 2 π bonds Linear around lassification R R R' σ bond energy: 88 kcal/mol π bond energy:

More information

O O HO, H 2 O. OR (2) One of the pair must form an enol MUCH more easily than the other

O O HO, H 2 O. OR (2) One of the pair must form an enol MUCH more easily than the other Carbonyl Condensation Reactions (Conjugate Addition) If we look at resonance structures for conjugated carbonyl compounds (often called α,β-unsaturated compounds), we ll see that there are TW sites for

More information

Substituted Alkanes. Alcohol Amine Ether Thiol

Substituted Alkanes. Alcohol Amine Ether Thiol Substituted Alkanes While alkanes have very few reactions that occur, combustion and some radical reactions, substituted alkanes display a variety of reactions and properties X ften the amount of information

More information

California State Polytechnic University, Pomona. Exam Points 1. Nomenclature (1) 30

California State Polytechnic University, Pomona. Exam Points 1. Nomenclature (1) 30 Chem 316 Final Exam Winter, 2008 Beauchamp ame: Topic Total Points Exam Points 1. omenclature (1) 30 Credit 2. Explanation of elative eactivities of Aromatic 20 Compounds or Carbonyl Compounds 3. eactions

More information

Chapter 2 Polar Covalent Bonds; Acids and Bases

Chapter 2 Polar Covalent Bonds; Acids and Bases John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds; Acids and Bases Javier E. Horta, M.D., Ph.D. University of Massachusetts Lowell Polar Covalent Bonds: Electronegativity

More information

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY MLEULAR REPRESENTATINS AND INFRARED SPETRSPY A STUDENT SULD BE ABLE T: 1. Given a Lewis (dash or dot), condensed, bond-line, or wedge formula of a compound draw the other representations. 2. Give examples

More information

1 Lecture 5 Resonance 1. Lone pair next to empty 2p orbital

1 Lecture 5 Resonance 1. Lone pair next to empty 2p orbital 1 Lecture 5 esonance 1. Lone pair next to empty 2p orbital sp 2 + is more common sp + is less common + needs electrons, has to overlap with a. an adjacent 2p lone pair with electrons b. an adjacent pi

More information

curly arrow represents the movement of 2 e

curly arrow represents the movement of 2 e F ADCAL ACT GAC YT MCAM Before we look at free radical chemistry a quick revision of mechanisms (again) You should all be happy with polar reaction nucleophile attacks electrophile curly arrow represents

More information

Identification of Unknown Organic Compounds

Identification of Unknown Organic Compounds Identification of Unknown Organic Compounds Introduction The identification and characterization of the structures of unknown substances are an important part of organic chemistry. Although it is often

More information

Physicochemical Properties of Drugs

Physicochemical Properties of Drugs Therapeutics I Michael B. Bolger 1/3/02 bjectives: At the end of the next hour: Physicochemical Properties of Drugs 1. The student should be able to calculate the degree of ionization for an acidic or

More information

AP Chemistry Chapter 22 - Organic and Biological Molecules

AP Chemistry Chapter 22 - Organic and Biological Molecules AP Chemistry Chapter - Organic and Biological Molecules.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The

More information

Where R = alkyl group, Nu = nucleophile and L = leaving group.

Where R = alkyl group, Nu = nucleophile and L = leaving group. Organic Chemistry (CEM311) Fall 2005 Dr. Robert F. Dias 9. SUBSTITUTIONS: S N 1, S N 2 2 basic kinds of substitution reactions: S N 2 = Substitution Nucleophillic Bimolecular S N 1 = Substitution Nuclophillic

More information

ORGANIC CHEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis

ORGANIC CHEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis RGANIC CEMISTRY I PRACTICE EXERCISE Elimination Reactions and Alkene Synthesis ) ne of the products that results when -bromo-,-dimethylcyclopentane is heated in ethanol is shown below. Give a mechanism

More information

Alkynes contain a C C triple bond

Alkynes contain a C C triple bond Chapter 8: Alkynes: an introduction to organic synthesis Alkynes contain a C C triple bond Acetylene: H-C C-H is the common name for ethyne, used as a torch fuel Alkyne nomenclature follows normal hydrocarbon

More information

Organometallic Chemistry

Organometallic Chemistry Organometallic Chemistry Compounds that contain M-C bonds ow strong or weak is a M-C bond? ow stable are the organometallic compounds? Organo-element Chemistry! Catalysis A catalyst is a substance

More information

Tuesday 19 June 2012 Afternoon

Tuesday 19 June 2012 Afternoon Tuesday 19 June 2012 Afternoon A2 GCE CEMISTRY A F324 Rings, Polymers and Analysis *F314730612* Candidates answer on the Question Paper. CR supplied materials: Data Sheet for Chemistry A (inserted) ther

More information

Principles Of Drug Action 1, Spring 2005, Halogenated Hydrocarbons HALOGENATED HYDROCARBON STRUCTURE AND CHEMISTRY.

Principles Of Drug Action 1, Spring 2005, Halogenated Hydrocarbons HALOGENATED HYDROCARBON STRUCTURE AND CHEMISTRY. Principles f Drug Action 1, Spring 2005, alogenated ydrocarbons ALGENATED YDRCARBN STRUCTURE AND CEMISTRY I. Introduction Jack DeRuiter alogenated hydrocarbons are organic compounds consisting of C-C,

More information

Q.1 Carbonyl compounds are formed by oxidation of alcohols;

Q.1 Carbonyl compounds are formed by oxidation of alcohols; arbonyl compounds 814 1 ARBYL MPUDS - Aldehydes and Ketones Q.1 arbonyl compounds are formed by oxidation of alcohols; a) Which type of alcohol is oxidised to an aldehyde? b) Which type of alcohol is oxidised

More information

Worksheet Addition reactions

Worksheet Addition reactions Worksheet Addition reactions The presence of electrons in alkenes allows addition reactions to take place. In general: In each case, the bond is broken and the e - are used to form a new bond in the product

More information

2.7 Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition

2.7 Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition. Acids and Bases: The Brønsted-Lowry Definition 2.7 Acids and Bases: The Brønsted-Lowry Definition Two frequently used definitions of acidity The Brønsted-Lowry definition Lewis definition Brønsted-Lowry acid A substance that donates a hydrogen ion

More information

Homework Chapter 21 Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions mandatory problems are highlighted (up to page 16)

Homework Chapter 21 Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions mandatory problems are highlighted (up to page 16) Homework Chapter 21 Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions mandatory problems are highlighted (up to page 16) SHORT ANSWER IUPAC Naming Instructions: Provide proper IUPAC

More information

methyl RX example primary RX example secondary RX example secondary RX example tertiary RX example

methyl RX example primary RX example secondary RX example secondary RX example tertiary RX example ucleophilic Substitution & Elimination hemistry 1 eginning patterns to knowfor S and E eactions - horizontal and vertical templates for practice Example 1 - two possible perspectives (deuterium and tritium

More information

IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests

IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests IDENTIFICATION OF AN UNKNOWN ORGANIC COMPOUND Classification Tests In this experiment you will attempt to identify an organic unknown from a selected group of compounds from the class of alcohols, aldehydes,

More information

INTERMOLECULAR FORCES

INTERMOLECULAR FORCES INTERMOLECULAR FORCES Intermolecular forces- forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together. Intramolecular - forces of chemical bonds within a molecule

More information

Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds

Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds Chemical Tests for Alkanes, Alkenes, and Aromatic Compounds Introduction There are four types of hydrocarbons: alkanes, alkenes, alkynes, and aromatic compounds, each type with different chemical properties.

More information

Carbonyl Chemistry (12 Lectures)

Carbonyl Chemistry (12 Lectures) arbonyl hemistry (12 Lectures) Aim of ourse Professor Donna G. Blackmond d.blackmond@imperial.ac.uk tel. 41193 oom 639 1 To build upon elements of Dr E.. Smith s and Dr. D.. Braddocks s course. To introduce

More information

Chemistry of the Functional Group

Chemistry of the Functional Group Name Lab Day Chemistry of the Functional Group Introduction: rganic molecules comprised only of carbon and hydrogen would be relatively unreactive and biologically unimportant. Inclusion of atoms of other

More information

CARBONYL COMPOUNDS - Aldehydes and Ketones

CARBONYL COMPOUNDS - Aldehydes and Ketones arbonyl compounds F324 1 ARBYL MPUDS - Aldehydes and Ketones Structure carbonyl groups consists of a carbon-oxygen double bond the bond is polar due to the difference in electronegativity aldehydes / ketones

More information

Addition Reactions of Carbon-Carbon Pi Bonds - Part 1

Addition Reactions of Carbon-Carbon Pi Bonds - Part 1 Addition eactions of arbon-arbon Pi Bonds - Part 1 3 δ+ 2 δ 3 3 3 + 2 3 2 3 What Is an Addition eaction? Addition reaction: Atoms or groups are added to opposite ends of a pi bond. X Y Why should I study

More information

CH101 Course Outline with Learning Outcomes

CH101 Course Outline with Learning Outcomes CH101 Course Outline with Learning Outcomes Staff: Dr. Fawaz Aldabbagh, Dr. David Cheung, Dr. Paul Kavanagh, Dr. Luca Ronconi (Coordinator) Module overview and general aims This Module lays a broad foundation

More information

Conjugation is broken completely by the introduction of saturated (sp3) carbon:

Conjugation is broken completely by the introduction of saturated (sp3) carbon: Chapter 16 Conjugation, resonance, and dienes Conjugation relies on the partial overlap of p-orbitals on adjacent double or triple bonds. A common conjugated system involves 1,3-dienes, such as 1,3-butadiene.

More information

Chapter 10 Introduction to Organic Chemistry: Alkanes. Organic Chemistry. 10.1 Organic Compounds. Organic vs. Inorganic.

Chapter 10 Introduction to Organic Chemistry: Alkanes. Organic Chemistry. 10.1 Organic Compounds. Organic vs. Inorganic. Chapter 10 Introduction to Organic Chemistry: Alkanes 10.1 Organic Compounds Organic Chemistry An organic compound is a compound made from carbon atoms. has one or more C atoms. has many H atoms. may also

More information

Suggested solutions for Chapter 3

Suggested solutions for Chapter 3 s for Chapter PRBLEM Assuming that the molecular ion is the base peak (00% abundance) what peaks would appear in the mass spectrum of each of these molecules: (a) C5Br (b) C60 (c) C64Br In cases (a) and

More information

Lecture 16 November 10, 2011. Metal-catalyzed cross-coupling reactions:

Lecture 16 November 10, 2011. Metal-catalyzed cross-coupling reactions: Metal-catalyzed cross-coupling reactions: Lecture 16 November 10, 2011 Let s move on now to talk about other metal-catalyzed cross-coupling reactions. All of these reactions involve the formation of a

More information

SN2 Ionic Substitution Reactions

SN2 Ionic Substitution Reactions SN2 Ionic Substitution Reactions Chem 14D Winter 2005 SN2 Ionic Substitution Reactions Substitution can occur in organic compounds that have an electronegative atom or group bonded to an sp 3 hybridized

More information

Chapter 11 Homework and practice questions Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations

Chapter 11 Homework and practice questions Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations Chapter 11 Homework and practice questions Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations SHORT ANSWER Exhibit 11-1 Circle your response in each set below. 1. Circle the least

More information

Chapter 11. Free Radical Reactions

Chapter 11. Free Radical Reactions hapter 11 Free Radical Reactions A free radical is a species containing one or more unpaired electrons Free radicals are electron-deficient species, but they are usually uncharged, so their chemistry is

More information