Stereospecific preparation of ethyl (E) and (Z)-3-aryl-3-phenylpropenoates by Heck reaction

Article abstract of DOI:10.1016/0040-4039(96)01608-5

Ethyl cinnamate reacts with several para-substituted aryl iodides under Jeffery-Larock conditions (Pd(OAc)₂, NaHCO₃, n-Bu₄NBr, DMF, Δ) to give ethyl (E)-3-aryl-3-phenylpropenoates as major compounds. The reaction of para-substituted ethyl cinnamates with iodobenzene under analogous conditions affords the corresponding Z isomers. The initially stereodefined alkene formed under Heck conditions undergoes a slow isomerization.