Electro-mechanochemical approach towards the chloro sulfoximidations of allenes under solvent-free conditions in a ball mill

An electro-mechanochemical protocol for the synthesis of vinylic sulfoximines has been developed. Utilising mechanochemically strained BaTiO3 nanoparticles, the catalytic active system is generated in situ by the reduction of copper(II) chloride. Various combinations of electron-donating and -withdrawing groups are tolerated, and the approach leads to products with difunctionalised double bonds in good to excellent yields. Attempts to add a sulfoximidoyl chloride to an alkyne proved difficult. Additions of a sulfonyl iodide to allenes and alkynes proceeded smoothly in the presence of silica gel without the need for activation by a piezoelectric material.