Palladium‐Catalyzed Sc(OTf)₃/Cs₂CO₃‐Assisted C−O Cross‐Coupling of Vinylidenecyclopropane‐Diesters with Phenolic Compounds

Abstract

We herein describe a method in the synthesis of aryl ether derivatives from a cross‐coupling reaction of vinylidenecyclopropane‐diesters (VDCP‐diesters) with phenolic compounds that can be purchased directly from dealers for the formation of C−O bond under palladium catalysis and assisted by Sc(OTf)3/Cs2CO3. This developed transformation proceeds through a nucleophilic addition at the 2‐position of allenic moiety at 50 °C for 4.0 h and are compatible with substituents such as bromine, iodine and borate on the phenolic substrates via a zwitterionic π‐propargyl palladium species, affording the desired products in 29% to 95% isolated yields. A plausible reaction mechanism has been also proposed on the basis of control, deuterium labeling experiments and density functional theory (DFT) calculations.