;The work presented in this thesis has been divided into two chapters. In chapter one, isomerization of 2-alkenylbenzoic acid derivatives to give (E)-alkenes was achieved with palladium(0) nanoparticles. The scope of this reaction includes carboxylic acid, ester, and amides and tolerates various substituents on the benzene ring. This isomerization reaction was catalyzed by recyclable Pd(0) nanoparticles, prepared in situ from PdCl2 and characterized by X-ray powder diffraction and scanning electron microscopy analyses. 1H NMR studies and kinetic modeling supported a stepwise process. This new process was applied to synthesize a natural dihydroisocoumarin with good efficiency.
In chapter two deals with the phthalide compounds synthesised. Allylic oxidation of 2-allylbenzoic acids (1) to give 3-ethylidenephthalides (3) or 3-vinylphthalides (4) was achieved with 1,2-bis(phenylsulfinyl)ethane palladium(II) acetate (White catalyst), oxygen in DMSO under the basic condition or the acidic conditon. The reaction conditions were applied to various substituted 2-allylbenzoic acids. The mechanism of this reaction is also discussed.