Functional Groups by Nucleophilic Substitution at Saturated Carbon

Introduction of Functional Groups by Nucleophilic Substitution at Saturated Carbon 

Entry 10 illustrates the application of the Mitsunobu reaction to synthesis of a steroidal iodide and demonstrates that inversion occurs. Entry 11 shows the use of the isolated Ph3P-Br2 complex. The reaction in Entry 12 involves the preparation of a primary iodide using the Ph3P-I2-imidazole reagent combination. 

The mechanistic aspects of nucleophilic substitution reactions were treated in detail in Chapter 4 of Part A. That mechanistic understanding has contributed to the development of nucleophilic substitution reactions as important synthetic processes. Owing to its stereospecificity and avoidance of carbocation intermediates, the Sw2 mechanism is advantageous from a synthetic point of view. In this section we discuss 

The mechanistic aspects of nucleophilic substitution reactions were treated in detail in Chapter 5 of Part A. That mechanistic understanding has contributed to the development of nucleophilic substitution reactions as importantl synthetic processes. The S 2 mechanism, because of its predictable stereochemistry and avoidance of carbocation intermediates, is the most desirable substitution process from a synthetic point of view. This section will discuss the role of S 2 reactions in the preparation of several classes of compounds. First, however, the important role that solvent plays in 8 2 reactions will be reviewed. The knowledgeable manipulation of solvent and related medium effects has led to significant improvement of many synthetic procedures that proceed by the 8 2 mechanism. 

SECTION 3.2. INTRODUCTION OF FUNCTIONAL GROUPS BY NUCLEOPHILIC SUBSTITUTION AT SATURATED CARBON 

CHAPTER 3 FUNCTIONAL GROUP INTERCONVERSION BY NUCLEOPHILIC SUBSTITUTION 

The reaction can be used for making either chlorides or bromides by using the appropriate tetraalkylammonium salt as a halide source. 

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