Membrane Microreactors for the On‐Demand Generation, Separation, and Reaction of Gases

Abstract

The use of gases as reagents in organic synthesis can be very challenging, particularly at al aboratory scale. This Concept takes into account recent studies to make the case that gases can indeed be efficiently and safely formed from relativelyi nexpensive commercially available reagents for use in aw ide range of organic transformations. In particular,w ea rgue that the exploitation of continuous flow membrane reactorse nables the effective separation of the chemistry necessary for gas formation from the chemistry for gas consumption, with these two stages often containing incompatible chemistry. The approach outlined eliminates the need to store and transport excessive amountso fp otentially toxic, reactive or explosive gases.T he on-demand generation, separation and reaction of an umber of gases, including carbon monoxide, diazomethane, trifluoromethyl diazomethane, hydrogen cyanide, ammonia and formaldehyde, is discussed. Gas-Liquid Membrane Microreactors Over recent years, microreactors and continuous flow technologies have emergeda sa ne nabling tool for the safe handling of hazardousc hemistry. [8, 9] In particular, for accessing "forgotten" and "forbidden" chemistry which cannotb ea ccessed under conventional batch conditions.

Self-Oscillating Liquid Gating Membranes with Periodic Gas Transport

“…This pressure-driven and self-oscillating system that utilizes its gas/liquid/solid interface interaction to achieve periodic gas transport, without the need for any complex external regulations. In addition, periodic gas transport could play a promising role in the fields of microreactors [ 26 , 27 ], chemical reactions [ 28 ], soft robots [ 29 , 30 ], and fluid transports [ 31 , 32 , 33 ].…”

A simple, safe and robust system for hydrogenation “without high-pressure gases” under batch and flow conditions using a liquid organic hydrogen carrier

“…1,2 The in situ and on demand generation of toxic or dangerous gases from commercially accessible surrogates of low toxicity and easy-handling provides a suitable alternative for conventional gas processing laboratory operations without the need for extra precautions. [3][4][5][6] In the case of transformations involving hydrogen, the development of hydrogenation reactions "without gases" is highly attractive. We understand the term "without gases" as those systems that do not require large gas reservoirs cylinders and are able to generate high purity hydrogen under demand and consumed in situ.…”

A solar tracker integrated microreactor for real-time sunlight induced ketene formation and API synthesis

“…23 However, there is a significant challenge in scaled-up reactions involving diazomethane. [24][25][26] To address the above-mentioned challenges, we decided to exploit the continuous flow technology to prepare a safe diazo intermediate. We subsequently employed a solar panel tracker reactor to further homologate the α-amino acid to the corresponding β-amino acid, ester, amide, thiolate, etc.…”