Chemistry

Chapter 8 ? 2010, Prentice Hall Organic Chemistry, 7th Edition L. G. Wade, Jr. Reactions of Alkenes Chapter 8 * Bonding in Alkenes Electrons in pi bond are loosely held. The double bond acts as a nucleophile attacking electrophilic species. Carbocations are intermediates in the reactions. These reactions are called electrophilic additions. Chapter 8 Chapter 8 * Electrophilic Addition Step 1: Pi electrons attack the electrophile. Step 2: Nucleophile attacks the carbocation. Chapter 8 Chapter 8 * Types of Additions Chapter 8 Chapter 8 * Addition of HX to Alkenes Step 1 is the protonation of the double bond. The protonation step forms the most stable carbocation possible. In step 2, the nucleophile attacks the carbocation, forming an alkyl halide.

Chapter 6 Organic Chemistry, 7th Edition L. G. Wade, Jr. Alkyl Halides: Nucleophilic Substitution and Elimination ?2010, Prentice Hall Chapter 6 * Classes of Halides Alkyl halides: Halogen, X, is directly bonded to sp3 carbon. Vinyl halides: X is bonded to sp2 carbon of alkene. Aryl halides: X is bonded to sp2 carbon on benzene ring. C C H H H C l vinyl halide C H H H C H H B r alkyl halide I aryl halide Chapter 6 Chapter 6 * Polarity and Reactivity Halogens are more electronegative than C. Carbon?halogen bond is polar, so carbon has partial positive charge. Carbon can be attacked by a nucleophile. Halogen can leave with the electron pair. Chapter 6 Chapter 6 * IUPAC Nomenclature Name as haloalkane.