Gold(I)-catalyzed double migration cascades toward (1E,3E)-dienes and naphthalenes

A novel gold(I)-catalyzed cascade cycloisomerization of a variety of propargylic esters leading to unsymmetrically substituted naphthalenes has been developed. This domino process involves an unprecedented tandem sequence of 1,3- and 1,2-migrations of two substantially different migrating groups. It is believed that this transformation proceeds via formation of 1,3-diene intermediate or its equivalent, which, upon carbocyclization and aromatization steps, transforms into the naphthalene skeleton. In addition, it was also demonstrated that a variety of 1,3-dienes can be accessed stereoselectively via the 1,3-migration-proton transfer cascade.