Metal-Free Oxidative Coupling Reactions via σ-Iodonium Intermediates: The Efficient Synthesis of Bithiophenes Using Hypervalent Iodine Reagents

The direct oxidative biaryl coupling reaction is an attractive tool for environmentally benign green chemistry. A novel direct method for the synthesis of bithiophene using a hyper-valent iodine reagent has been developed. The reaction mechanism has also been investigated, casting light on the reaction intermediate and revealing the reactivity with iodonium salts.