Alkenyl halides reaction patterns

Reaction Patterns of Aryl, Alkenyl and Benzyl Halides and Pseudohalides... 

Reaction patterns of aryl, alkenyl and benzyl halides and pseudohalides... 

The outcome of the reaction of alkenyliodonium salts with halide salts depends on the substitution pattern of the iodonium substrate. Thus, treatment of ( )-alkenyliodonium salts with tetra(n-butyl)ammonium halides (X = Cl, Br or I) afforded exclusively the corresponding (Z)-alkenyl halides, the product of inversion of configuration.The mechanism of these reactions with configuration inversion still remains a matter of debate, an SN2-type transition being postulated. When the same reaction was performed with a combination of cuprous halides and potassium halides at room temperature in the dark, complete retention of stereochemistry was observed. 

Arylmetals can be coupled with alkenyl and alkynyl halides. In these cases, the reverse polarity affinity patterns, i.e., the alkenyl-aryl and alkynyl-aryl coupling reactions... 

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