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Chapter 6 Alkyl Halides: Nucleophilic Substitution

and Elimination

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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• Alkyl halide: It has a halogen atom bonded to one of the sp3 carbon atoms of an alkyl group. • Vinyl halide: It has a halogen atom bonded to one of the sp2 carbon atoms of an alkene. • Aryl halide: It has a halogen atom bonded to one of the carbon atoms of an aromatic ring

6.1 Introduction

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.2 Nomenclature of Alkyl Halides

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.3 Common Uses of Alkyl Halides 6.31 Solvents (CCl4) 6.32 Reagents 6.33 Anesthetics 6.34 Freons: Refrigerants and Foaming Agents 6.35 Pesticides

6.4 Physical Properties of Alkyl Halides

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.5 Preparation of Alkyl Halides 6.51 Free-Radical Halogenation

6.52 Allylic Bromination

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.6 Reactions of Alkyl Halides: Substitution and Elimination

Alkyl halides are easily converted to many other functional groups. The halogen atom can leave with its bonding pair of electrons to form a stable halide ion; we say that a halide is a good leaving group.

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.7 Second-Order Nucleophilic Substitution: The SN2 Reaction

6.71 Mechanism

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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• The reaction-energy diagram for the reaction of methyl iodide with hydroxide

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.8 First-Order Nucleophilic Substitution: The SN1 Reaction

6.81 The mechanism of the SN1

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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• Reaction-energy diagrams of the SN1 and SN2 reactions

6.9 First-Order Elimination: The E1 Reaction

An elimination involves the loss of two atoms or groups from the substrate, usually with formation of a pi bond. Elimination reactions frequently accompany and compete with substitutions.

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

11 Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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• Reaction-energy diagram of the E1 reaction

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition

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6.9 Second-Order Elimination: The E2 Reaction

• The concerted E2 reaction takes place in a single step. A strong base abstracts a proton on a carbon next to the leaving group, and the leaving group leaves. The product is an alkene

Reference: Organic Chemistry", L.G. Wade, Printice Hall, 8th Edition