Micro-total envelope system with silicon nanowire separator for safe carcinogenic chemistry

Abstract

Exploration and expansion of the chemistries involving toxic or carcinogenic reagents are severely limited by the health hazards their presence poses. Here, we present a micro-total envelope system (μ-TES) and an automated total process for the generation of the carcinogenic reagent, its purification and its utilization for a desired synthesis that is totally enveloped from being exposed to the carcinogen. A unique microseparator is developed on the basis of SiNWs structure to replace the usual exposure-prone distillation in separating the generated reagent. Chloromethyl methyl ether chemistry is explored as a carcinogenic model in demonstrating the efficiency of the μ-TES that is fully automated so that feeding the ingredients for the generation is all it takes to produce the desired product. Syntheses taking days can be accomplished safely in minutes with excellent yields, which bodes well for elevating the carcinogenic chemistry to new unexplored dimensions.

Integrated CO2 capture-fixation chemistry via interfacial ionic liquid catalyst in laminar gas/liquid flow

“…The superamphiphobic SiNWs on the bottom panel of the reactor was fabricated by Ag-assisted anisotropic etching of silicon wafer (100) according to the reported methods 21 22 , and the DBU-ILs were selectively positioned on the tips of cone-shaped bundles of SiNWs in the form of a thimble ( Supplementary Fig. 1 ).…”

“…Due to high boiling point (189 °C) of DMSO solvent, it was troublesome to work-up by evaporating the solvent for product isolation under vacuum. To make easy work-up procedure we have switched low volatile DMSO solvent to highly volatile dichloromethane (DCM, boiling point 40 °C) after the reaction 21 . In this work, therefore, liquid–liquid extraction of droplet microfluidics is adopted to isolate the synthesized 2-oxazolidones in DCM from the DMSO mixture, followed by separation of the DCM mixture using a phase microseparator embedded with hydrophobic PTFE membrane ( Supplementary Figs 32 and 33 ) 30 33 34 .…”

The Concept of Chemical Generators: On-Site On-Demand Production of Hazardous Reagents in Continuous Flow

“…In 2016, they introduced the so-called μ-TES (micrototal envelop system) format for the safe generation, separation/purification, consumption, and quenching of CMME ( Scheme 6 ). 22 Key to this strategy was the use of a membrane-free superamphiphobic SiNW (silicon nanowire) microseparator where separation occurs at the interface of the stable gas–liquid laminar flow. CMME was generated from hexanoyl chloride and dimethoxymethane by heating in a coil reactor.…”

Integration of Bromine and Cyanogen Bromide Generators for the Continuous‐Flow Synthesis of Cyclic Guanidines

“…[2] In an ideal scenario,t he complete operation, including generation of the reagent, its separation, and downstream consumption, is performed in af ully contained fashion to ensure zero exposure to the hazardous material throughout operation. [2,3] Several continuous generators of highly reactive and/or hazardous/toxic reagents following these principles have been reported in recent years. [2][3][4][5][6][7][8][9] As ignificant part of our current research is directed toward developing new methods and broadening the scope of the chemical generator concept.…”

“…[2,3] Several continuous generators of highly reactive and/or hazardous/toxic reagents following these principles have been reported in recent years. [2][3][4][5][6][7][8][9] As ignificant part of our current research is directed toward developing new methods and broadening the scope of the chemical generator concept. In this context, cyanogen bromide (BrCN) is an interesting target molecule:i ti sa n exceptionally versatile reagent in organic synthesis [10,11] that most frequently participates as an electrophilic cyanide source and reacts with N, O, S, C, and Pn ucleophiles to generate products such as cyanamides, [12] guanidines, [13] cyanates, [14] and nitriles, [15] (Scheme 1).…”