Metal nitrate driven nitro Hunsdiecker reaction with α,β-unsaturated carboxylic acids under solvent-free conditions

Hunsdiecker reactions with α,β-unsaturated carboxylic acids were conducted under solvent-free conditions in the presence of a few drops of HNO3 together with a variety of metal nitrates [Mg(NO3)2, Sr(NO3)2], Al(NO3)3, Ca(NO3)2, Ni(NO3)2, Cd(NO3)2, Zn(NO3)2, Hg(NO3)2, AgNO3, ZrO(NO3)2, UO2(NO3)2, Th(NO3)2] or ammonium nitrate. α,β-Unsaturated aromatic carboxylic acids underwent nitro decarboxylation to afford β-nitro styrenes in moderate to good yields, while α,β-unsaturated aliphatic carboxylic acids underwent decarboxylation to yield the corresponding nitro derivatives.