Halogenation as a Synthetic Technique

In this chapter, we have seen that radical chlorination and radical bromination are both thermodynamically favorable processes. Bromination is slower but is more selective than chlorination. Both reactions are used in synthesis. When the starting compound has only one kind of hydrogen (all hydrogen atoms are equivalent), chlorination can be accompUshed without having to worry about regiochemical outcomes  

When different types of hydrogen atoms are present in the compound, it is best to use bromination in order to control the regiochemical outcome and avoid a mixture of products  

In truth, even radical bromination has very Hmited utility in synthesis. Its greatest utihty is to serve as a method for introducing a functional group into an alkane. When the starting material is an alkane, there is very Htde that can be done other than radical halogenation. By introducing a functional group into the compound, the door is opened for a wide variety of reactions  

Chapter 12 is devoted entirely to synthesis techniques, and we will revisit the role of radical halogenation in designing syntheses. 

REVIEW OF REACTIONS SYNTHETICALLY USEFUL RADICAL REACTIONS 

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