Supported CuO–SnO 2 Nanocatalysts for In situ Oxidation and Aldol Condensation of Toluene With C2 and C3 Alcohols

ABSTRACT CuO–SnO 2 nanocomposites supported on structurally and chemically diverse porous matrices (zeolite HY, HZSM‐5, MgO, and MgAl‐LDH) were synthesized to unravel support‐dependent tandem oxidation–condensation catalysis. The catalysts, denoted as CuO–SnO 2 /Y, CuO–SnO 2 /ZSM‐5, CuO–SnO 2 /MgO, and CuO–SnO 2 /LDH were evaluated for the one‐pot in situ oxidation–condensation of toluene with C2 and C3 alcohols to generate β‐aryl enals and enones. The catalytic efficiency followed the order—CuO–SnO 2 /Y> CuO–SnO 2 /ZSM‐5> CuO–SnO 2 /LDH > CuO–SnO 2 /MgO, highlighting the role of support acidity and pore topology in the reaction. Using ethanol, parallel oxidation to acetaldehyde and acetone yielded cinnamaldehyde and benzylidene acetone. Whereas, isopropanol afforded benzylidene acetone with high selectivity. The reaction progress was monitored by in situ IR spectroscopy. The formation of the products was confirmed by GC–MS analysis. DFT calculations revealed low energy barriers for both CuO‐mediated ethanol oxidation and SnO 2 ‐facilitated toluene activation. The formation of acetaldehyde from ethanol was verified using the modified Hantzsch method. The combined experimental–computational insights established a clear structure–property–function relationship. This work demonstrates a green one‐pot strategy for producing β‐aryl enals and enones, highlighting the potential of CuO–SnO 2 /support catalysts for tandem oxidative synthesis of value‐added products.