Synthesis of Leaf Alcohol Using Lindlar Catalyst: From Batch to Continuous‐Flow

Abstract Leaf alcohol is typically produced through batch selective semi‐hydrogenation of 3‐hexyn‐1‐ol using Lindlar catalyst. Although several catalysts have been described for this transformation, they are manufactured on a gram scale, posing challenges for industrialization. We decided to implement this process in flow. We show that, in the absence of quinoline, precise control of the reaction's progress is crucial for achieving high selectivity. To reduce the pressure drop, the catalyst was pelletized using CaCO 3 as a binder. At 40 °C and under 1 bar of H 2 , total conversion was obtained in less than 1 min. However, selectivity at high conversion is lower due to mass transfer limitations and a broad contact time distribution. Selectivity can be enhanced by increasing the liquid flow rate, whereas high conversion can be attained by operating in a recirculating flow mode. Under this configuration, high selectivity at high conversion can be achieved in flow using a commercial Lindlar catalyst.