Vanadium (IV)oxo catalyzed One-Pot transformation of cinnamate to aromatic ester and its mechanistic aspects

Metal-catalyzed oxidative cleavage of unsaturated carbon–carbon bond is among the utmost valuable chemical transformations in synthetic organic chemistry. However, the direct transformation of cinnamate to benzoate remains an unsolved task in the series. Herein, we have developed an unprecedented one-pot strategy for the direct transformation of cinnamate esters to aromatic ester using V-catalyst [(L²)V^IVO](ClO₄) and green oxidant H₂O₂ in alcohol-reflux condition. The reaction on cinnamate proceeded via C[dbnd]C bond breaking to generate aldehyde intermediate, followed by oxidative esterification to yield two carbon less aromatic esters in 52–95% yields. Further, experimental and DFT studies confirmed the mechanism and in-situ aldehyde formation which consequently supported to the developed protocol.