Lewis Acid-Driven Meyer-Schuster-Type Rearrangement of Yne-Dienone

摘要

Developed herein is a Cu(II)-catalyzed Meyer-Schuster-type rearrangement of alkyne-tethered cyclohexadienone for the construction of m-enone-substituted phenols. The reaction involves an uncommon 5-exo-trig 1,6-enyne cyclization of alkyne-tethered-cyclohexadienone, aromatization-triggered C-O bond cleavage, and an electrocyclic 4 pi-ring-opening of oxetene intermediate. This atom-efficient transformation provides access to a wide range of synthetically important alpha-(m-substituted phenol)-alpha,beta-unsaturated ketones, featuring a broad scope with labile functional group tolerance. The gram-scale demonstration makes this transformation synthetically viable. The synthetic application of alpha,beta-unsaturated ketones is also showcased.