Pd-catalyzed norbomene-mediated

Scheme 30 Pd-catalyzed norbomene-mediated C2-alkylation of IH-indoles.

In this novel domino sequence, norbornene (or norbomadiene) acts as a promoter as well as a reaction partner. It enters and exits the catalytic cycle and is eventually incorporated in the product, and therefore the reaction requires an excess of this reagent. The standard Pd-catalyzed/norbomene-mediated ortho alkylation of the aryl iodide with the alkyne would form the arylpalladium species 146 (Scheme 3.36). Intramolecular carbopalladation onto the tethered alkyne unit gives vinylpalladiuml47. Intermolecularcarbopalladationwitha moleculeofnorbornene... 

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