(379c) Oxidative Functionalization of Long-Chain Alkanes By Pulsed Plasma Discharges at Atmospheric Pressure

The functionalization of saturated hydrocarbons remains a challenge in synthetic chemistry due to the low reactivity of the C-H bonds. Herein, an eco-friendly route for the oxidation of long aliphatic alkanes using non-thermal, atmospheric plasma processing is presented. A pulsed dielectric barrier discharge (DBD) was employed in He/O₂ gas mixtures to functionalize long hydrocarbons. Secondary alcohols and ketones were identified as the main products at relatively high yields at intermediate times, and complex oxygenates at longer times. Lighter hydrocarbon products and decarboxylation were also observed under more aggressive conditions. The direct hydroxylation of alkyl radicals and disproportionation reactions appear as the main pathways toward forming alcohols and ketones. The results promise to functionalize long hydrocarbon molecules at ambient conditions using catalyst-free plasma discharges.