Palladium-Catalyzed Annulative Coupling of Spirovinylcyclopropyl Oxindoles with p-Quinone Methides

Abstract

Pd-catalyzed annulative coupling of spirovinylcyclopropyl oxindoles with p-quinone methides has been accomplished via cascade carbon–carbon bond formation to afford bis-spirooxindole scaffolds. The mild reaction conditions, diastereoselectivity, functional group diversity, post-synthetic transformations, and mechanistic studies using DFT calculations are the important practical features.

Palladium-catalyzed and ligand-controlled divergent cycloadditions of vinylidenecyclopropane-diesters with para-quinone methides enabled by zwitterionic π-propargyl palladium species

“…2 Several strategies for the efficient construction of spiro-cyclohexadienones have been reported in recent years. 3 The p -QM consists of a cyclohexadiene moiety that is in para -conjugation with a carbonyl group and an exo -methylene component, which serves as an important intercalated allylic Michael receptor. 1 c ,4 The ability of the para double bond to undergo nucleophilic addition with a wide range of nucleophilic reagents enables [2 + n ] spirocyclization products to be provided.…”