Αποτελέσματα Αναζήτησης
Nucleophilic Substitution Reactions. SN1 and SN2. A nucleophile, a species with an unshared electron pair (lone-pair electrons), reacts with an alkyl halide (substrate) by replacing the halogen substituent (leaving group).
Chapter 6 Nucleophilic Substitution. In this chapter we re-examine nucleophilic substitution reactions in more detail, paying particular attention to stereochemistry and other details of the reaction mechanism. We will look at what makes a good nucleophile and we will examine solvent effects on substitution reactions.
An aromatic nucleophilic substitution in organic chemistry may simply be defined as a chemical reaction where the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. The aromatic nucleophilic substitution can primarily occur via three different routes as given below.
SN2 (Substitution Nucleophilic Bimolecular) Mechanism. In SN2 reactions, the "SN" stands for "nucleophilic substitution", and "2" means that the rate-determining step is bimolecular. In other words, a stronger nucleophile displaces a weaker one via the formation of a transition state.
In a substitution reaction, one atom (or group of atoms) is replaced by another atom (or group of atoms). The atom or group that is lost is called the leaving group and the atom or group that is added is a nucleophile.
Nucleophilic substitution reactions are ionic reactions that break and make chemical bonds by transfers of pairs of electrons. We illustrate this using a general representation of a nucleophilic
6 Αυγ 2007 · NUCLEOPHILIC SUBSTITUTIONS. OBJECTIVES. Describe two pathways (mechanisms) to account for substitution at sp3 carbons bearing an electronegative atom (leaving group) Discuss the effect of starting material (substrate), leaving group, reagent (a nucleophile) and reaction conditions on the course of a reaction.
