Femtosecond laser-engineered 3D microfluidic chips: Synthesis system sprouting highly efficient multiphase organic reactions

Recent developments in the utilization of microfluidic chips (MFCs) have shown their potential utility in multiphase organic synthesis by enabling efficient organic reactions in flow chemistry. However, MFCs technology has been wandering in the laboratory of small dose synthetic routes, which is limited to the level of tiny fluid flux. To address this issue, we herein report the first case of the chips with high-throughput 3D channels produced by femtosecond laser being used to create a time-saving, cost-effective and risk-free approach suitable for large-scale flow synthesis. Several multiphase reactions have been successfully prepared on demand in our designed flow synthesis system containing 3D MFCs: 1) benzyl alcohol was converted to benzaldehyde in 3 min with a yield of 97.50% by liquid-liquid two-phase transfer catalytic oxidation; 2) organozinc reagents and alpha-cyano carbonyl carbon compounds were synthesized by solid-liquid two-phase metal insertion reaction in 7 min, and the yield was up to 100%; 3) benzoic acid was synthesized by gas-liquid two-phase carboxylation reaction in 2.8 s with a yield of 96%. Significant gains in production rate result from the effective scaling of flow reactors from microliters per hour in MFCs to intermediate milliliters per minute without affecting mass transport performance. Meanwhile, our 3D MFCs show excellent mass and heat transfer efficiency in large-scale industrial units, breaking through the bottleneck in this field. As a result, it is possible to imagine the creation of a new, stream-lined flow synthetic technique via MFCs for green multiphase organic synthesis.(c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Recent advancements in microfluidic chips (MFCs) have shown potential for efficient organic reactions in flow chemistry. However, current MFCs are limited to small-scale synthesis. In this study, we introduce high-throughput 3D MFCs created by femtosecond laser, enabling large-scale flow synthesis with enhanced production rate and mass transport performance. Multiple multiphase reactions were successfully conducted in our 3D MFCs, demonstrating their excellent mass and heat transfer efficiency. This breakthrough paves the way for a streamlined and green approach to multiphase organic synthesis.