Direct Stereoselective β-Arylation of Enol Ethers by a Decarboxylative Heck-Type Reaction

Article abstract of DOI:10.1002/ejoc.201901877

Despite remarkable advances to promote regio- and stereoselective decarboxylative arylation of inactivated olefins with benzoic acid derivatives, methodologies involving hetero-substituted alkenes are still lacking. Herein, Pd^II-catalyzed decarboxylative Heck coupling of α-alkoxyacrylates with (hetero)aryl carboxylic acids for the stereocontrolled production of (Z)-β-heteroarylated vinyl ethers is reported. This methodology offers a rational and step-economical route to the synthesis of attractive β-arylated α-alkoxy α,β-unsaturated carboxylates family which emerged as a relevant class of building blocks with different applications. Mechanistically, whereas electron rich benzoic acids undergo a Pd^II-catalyzed decarboxylation, electron-deficient substrates proceed through silver(I)-mediated decarboxylation, explaining thus the formation of stereoisomers (E) and (Z) of β-arylated vinyl ethers in presence of these latter.