ABSTRACT
This chapter will discuss the concept of a nucleophile that reacts at an sp3 carbon atom to form a new molecule where another atom or group has replaced one in the molecule that is attacked. This type of reaction is called a substitution (see Chapter 6, Section 6.6, for a brief introduction). The Lewis base analogy of a two-electron donor is used to explain the reactivity of nucleophiles, but the target is the sp3 carbon of an alkyl halide, or related compounds. This reaction can occur in two fundamental ways: one by direct displacement and the other by ionization to a carbocation followed by attack of the nucleophile.
