Addition Reactions with Electrophilic Sulfur and Selenium Reagents

Addition Reactions with Electrophilic Sulfur and Selenium Reagents 

Compounds having divalent sulfur and selenium atoms bound to more electronegative elements react with alkenes to give addition products. The mechanism is similar to that in halogenation and involves of bridged cationic intermediates. 

In many synthetic applications, the sulfur or selenium substituent is subsequently removed by elimination, as is discussed in Chapter 6. 

Selenylation can also be done under conditions in which another nucleophilic component of the reaction captures the selenium-bridged ion. For 

Electrophilic Additions to Carbon-Carbon Multiple Bonds 

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