Design and catalytic performance of a novel 2D copper MOF for green synthesis of tetrahydrobenzo[b]pyrans

This study explores the development and use of a novel 2D MOF as a heterogeneous catalyst in organic synthesis. The phosphonocarboxylic acid m -PO ₃ CH ₂ C ₆ H ₄ CO ₂ H ( L ) has been employed in the synthesis of a metal carboxyarylphosphonate. The 2D MOF [Cu(H ₂ O)( m -PO ₃ CH ₂ C ₆ H ₄ CO ₂ H)] _n ( 1 ) was synthesized in both crystal ( 1 ) and nanostructure ( 1′ ) forms, characterized by X-ray single crystallography, SEM, TGA, FT-IR, PXRD, EDX, Mapping, and nitrogen adsorption–desorption, and employed for the efficient green synthesis of tetrahydrobenzo[b]pyrans (THBPs). The crystal structure features alternating inorganic and organic layers. The organic layers have supramolecular dimers of carboxylic acid groups, two molecules bonded to two inorganic layers. THBP yield optimization conditions were determined with water/ethanol as solvents, using a catalyst loading of 0.06 g for 95% yields. The synthesized catalyst demonstrated high catalytic activity, broad applicability to various aldehyde substrates, and notable reusability, maintaining high yields for up to seven cycles after the reaction. Compared with previous catalytic systems, compound ( 1′ ) exhibited superior efficiency and recyclability. These findings highlight the potential of this novel 2D MOF for facilitating environmentally friendly and efficient organic syntheses.