Development of a RuHAP-Packed-Bed Reactor for Continuous Flow Aerobic Oxidation.

The aerobic oxidation of alcohols is valuable but often limited by toxic reagents, waste, and harsh conditions. Using a Ru3+-hydroxyapatite (RuHAP)-packed-bed reactor under low-pressure O2, we achieved efficient, reproducible oxidations with TONs of >18,000 after two catalyst regenerations. A two-step continuous flow process integrating oxidation and Knoevenagel condensation delivered products in excellent yields, demonstrating a scalable, safe, and sustainable method with high selectivity and mild conditions for fine chemical and pharmaceutical synthesis.