Stille-Coupling Reaction

The palladium-catalyzed cross – coupling reaction between organohalo compounds or organo triflates or acid chlorides and organostannanes under mild conditions furnishes carbon – carbon single bond is called as Stille-Coupling Reaction.

1. In Stille-Coupling Reaction, the reactants are organohalo compounds or organo triflates or acid chlorides and organostannanes.

2. In Stille-Coupling Reaction, in the reactants organohalocompounds or organo triflates or acid chlorides the organic group may be acyl, allyl, aryl, vinyl, and benzyl.

3. The reactivity order of organo halo compounds (or) triflets towards activated alkenes is as follows,
R – I > R – OTF > R – Br >> R – Cl

4. In Stille-Coupling Reaction, in the reactants organo stanane, the organic group may be aryl, vinyl.

5. In Stille-Coupling Reaction the reactants organohalocompounds or organo triflates or acid chlorides are in electrophilic nature, while the organo stananes are in nucleophilic nature.

6. The Stille-Coupling reagent: The combination of catalytical amount of Palladium Pd (0) Pd (II), milder conditions is called as Stille-Coupling reagent.

7. In Stille-Coupling reaction, the solvents used are solvents like DMF (dimethyl formamide), THF, dtethylether, benzene & chloroform etc,

8. In Stille-Coupling reaction, the products are may be – stereo specific and regioselective aldehydes, esters, cyanides and alcohols.

9. In Stille-Coupling, stereochemistry is retained i.e. whatever the reactant stereochemistry is passed throughout the product stereochemistry (reactant stereochemistry and product stereochemistry is same).

10. The limitation of the stille coupling reaction is with toxicity of organo stanane reagents especially the low-molecular weighted alkyl tin compounds. To overcome this problem, the preparation and the reactions of organostannes must be carried out in a well-ventilated hood.