High-throughput screening of molecular catalysts using automated liquid handling, injection, and microdevices

A new concept for the high-throughput screening of multiphase reactions involving molecular catalysts is described. It combines pulse injections of catalysts and substrate and mixing in a microdevice. The novelty of the concept resides in dynamic sequential vs. batchwise operations. Some advantages over traditional batch parallel operations are lower inventory of sample (down to μg) coupled with accurate control of reaction time, larger range of operating conditions (pressure, temperature), simpler and fewer electromechanical moving parts and easy automation. Results on liquid-liquid (biphasic allylic alcohol isomerization), and gas-liquid (asymmetric hydrogenation) reactions indicates that the number of tests per day can easily reach 50 d - 1 with inventory of sample (Rh) per test as low as 5 μg.