Subject: Submission of Manuscript for Publication in Molecular Catalysis

Hydroformylation represents a pivotal transformation for the synthesis of aldehydes; however, conventional processes rely on hazardous syngas (CO/H₂) and expensive rhodium-based catalysts. Herein, we report a microwave-assisted palladium-catalysed hydroformylation protocol employing glyoxylic acid as an efficient syngas surrogate, enabling the in situ generation of reactive CO/H₂ equivalents under mild and safe conditions. A series of Schiff base ligands (LA–LD) and their corresponding Pd(II) complexes were synthesised and systematically evaluated. Among them, PdLA exhibited superior catalytic performance, affording up to 80% yield of heptanal and 76% yield of hexanal with excellent regioselectivity (L/B up to 95:5) within 20 min at 120 °C. Mechanistic investigations supported by NMR studies suggest the involvement of palladium–hydride and acyl intermediates. The present methodology eliminates the need for external gaseous reagents, reduces reaction time, and provides a sustainable and operationally simple alternative to conventional hydroformylation processes. This study highlights the potential of glyoxylic acid as a practical syngas surrogate in palladium-catalysed transformations.