Pd-catalyzed C-arylation of unsaturated compounds with pentavalent triarylantimony dicarboxylates

Triarylantimony(V) derivatives Ar3SbX2 (X=Hal or acyloxy) were prepared by reaction of Ar3Sb with equimolar amounts of a peroxide ROOH (R=t-Bu, H) in the presence of an acid or an anhydride in good to excellent yields. Ar3Sb(O2CR)2 are mild and efficient C-arylation reagents of unsaturated compounds (methyl acrylate, styrene, 2-phenylpropene and acrylonitrile) under palladium catalysis at 50 °C, with PdCl2 being the most effective catalyst. Ar3SbHal2 do not react under these conditions.