Synthesis of Seven-Membered Benzolactones by Nickel-Catalyzed C-H Coupling of Benzamides with Oxetanes.

A NiCl2 (PEt3 )2 -catalyzed regioselective C-H coupling of 8-aminoquinoline-derived benzamides with oxetanes has been developed. The reaction proceeds with concomitant removal of the 8-aminoquinoline auxiliary to directly form the corresponding seven-membered benzolactones, which frequently occur in natural products and bioactive molecules. Additionally, no stereochemical erosion is observed during the course of the reaction, and the use of enantioenriched and substituted oxetane thus provides a new avenue to the optically active benzolactone.