Alkyl halides nucleophiles

These reactions follow first-order kinetics and proceed with racemisalion if the reaction site is an optically active centre. For alkyl halides nucleophilic substitution proceeds easily primary halides favour Sn2 mechanisms and tertiary halides favour S 1 mechanisms. Aryl halides undergo nucleophilic substitution with difficulty and sometimes involve aryne intermediates. 

First order Rate = k[alkyl halide] (Section 8 8) Second order Rate = k[alkyl halide][nucleophile] (Section 8 3)... 

CHAPTER 11 Reactions of Alkyl Halides Nucleophilic Substitutions and Eliminations... 

Chapter 11, Reactions of Alkyl Halides Nucleophilic Substitutions and Eliminations—A discussion of the El cB reaction has been added to Section 11.10, and a new Section 11.11 discusses biological elimination reactions. 

Alkyl Halide Nucleophile Catalyst (mole equiv- alent) Temp- erature CC) Time (min- utes) Yield of Sulfide" (%)... 

Lysine, 4-amino Alkyl halides Nucleophilic substitution... 

CHAPTER 6 Alkyl Halides Nucleophilic Substitution and Elimination... 

Another factor affecting the nucleophilicity of these ions is their solvation, particularly in protic solvents. A protic solvent is one that has acidic protons, usually in the form of O—H or N—H groups. These groups form hydrogen bonds to negatively charged nucleophiles. Protic solvents, especially alcohols, are convenient solvents for nucleophilic substitutions because the reagents (alkyl halides, nucleophiles, etc.) tend to be quite soluble. 

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