Regioselective Synthesis of <i>n</i> ‐Nonanal and Aldehyde‐Containing Polysiloxanes via Rh‐Catalyzed Hydroformylation Enhanced by A New Silicon‐Tethered Multidentate Phosphine Ligand

Abstract Catalytic synthesis of long‐chain alkyl aldehydes presents a significant challenge in homogeneous catalysis and organic synthesis due to the difficulty in regioselective control. Here we report a rhodium‐catalyzed high chemo‐ and regio‐selective hydroformylation of 1‐octene that would be highly useful intermediates in chemical industry. Notably, the easy made tetradentate P‐ligands L1 and L2 can effectively suppress hydrogenation and isomerization reaction of olefins and give the desired aldehydes in high yield and good regioselectivity. Control experiments reveal the tetradentate P‐ligands is important for controlling selectivity because the high regioselectivity is found to benefit from the presence of four phosphorus atoms manifesting in the formation of much more efficient coordination interactions to give relatively stable rhodium complexes.