Cp*Co(III)-Catalyzed C(8)-Nucleophilic Cascade Cyclization of Quinoline -Oxide with 1,6-Enyne.

The C(8)-selective nucleophilic cascade cyclization of quinoline -oxide with easily derived 1,6-enyne from phenol derivatives is demonstrated. A variety of quinoline -oxide and alkynes are discovered to be suitable for producing a library of quinoline -oxide tethered -hydrobenzofurans with high yields and excellent functional group tolerance. The utility of the protocol has been accomplished by post-synthetic modification of the cyclized product.