Palladium-Free, Highly Efficient Mesoporous Tin Silicates Catalytic Acyl Sonogashira Coupling Reaction

Three-dimensional mesoporous tin silicates (PS-2) with different Si/Sn mole ratios are synthesized by direct hydrothermal treatment via a soft-templating technique under acidic conditions. The first example of PS-2 catalysts composed of tunable textural properties and designed to overcome the problems associated with stoichiometric acetylenic Grignard reagents and large amounts of uneconomical Pd catalysts indeed shows that a new synthetic approach toward direct acyl Sonogashira coupling reaction through C–C coupling has been developed under palladium metal- and ligand-free conditions. Both aromatic and aliphatic alkynes could react with acid halides to produce ynones and its derivatives under solvent-free conditions.