Search results
Search for "semipermeable membrane" in Full Text gives 3 result(s) in Beilstein Journal of Organic Chemistry.
Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies
- Conrad Kuhwald,
- Sibel Türkhan and
- Andreas Kirschning
Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70
- diperoxide. The reaction mixture was then transferred to a continuous phase separator equipped with a semipermeable membrane, from where the organic phase was transferred to a stainless steel loop reactor. Here, the macrocyclic triperoxide 91 was subjected to pyrolysis at 270 °C. This was done by inductive
Graphical Abstract
Figure 1: Inductive heating, a powerful tool in industry and the Life Sciences.
Figure 2: Electric displacement field of a ferromagnetic and superparamagnetic material.
Figure 3: Temperature profiles of reactors heated conventionally and by RF heating (Figure 3 redrawn from [24]).
Scheme 1: Continuous flow synthesis of isopulegol (2) from citronellal (1).
Scheme 2: Dry (reaction 1) and steam (reaction 2) methane reforming.
Scheme 3: Calcination and RF heating.
Scheme 4: The continuously operated “Sabatier” process.
Scheme 5: Biofuel production from biomass using inductive heating for pyrolysis.
Scheme 6: Water electrolysis using an inductively heated electrolysis cell.
Scheme 7: Dimroth rearrangement (reaction 1) and three-component reaction (reaction 2) to propargyl amines 8 ...
Figure 4: A. Flow reactor filled with magnetic nanostructured particles (MagSilicaTM) and packed bed reactor ...
Scheme 8: Claisen rearrangement in flow: A. comparison between conventional heating (external oil bath), micr...
Scheme 9: Continuous flow reactions and comparison with batch reaction (oil bath). A. Pd-catalyzed transfer h...
Scheme 10: Continuous flow reactions and comparison with batch reaction (oil bath). A. pericyclic reactions an...
Scheme 11: Reactions under flow conditions using inductively heated fixed-bed materials serving as stoichiomet...
Scheme 12: Reactions under flow conditions using inductively heated fixed-bed materials serving as catalysts: ...
Scheme 13: Two step flow protocol for the preparation of 1,1'-diarylalkanes 77 from ketones and aldehydes 74, ...
Scheme 14: O-Alkylation, the last step in the multistep flow synthesis of Iloperidone (80) accompanied with a ...
Scheme 15: Continuous two-step flow process consisting of Grignard reaction followed by water elimination bein...
Scheme 16: Inductively heated continuous flow protocol for the synthesis of Iso E Super (88) [91,92].
Scheme 17: Three-step continuous flow synthesis of macrocycles 89 and 90 with musk-like olfactoric properties.
Properties of PTFE tape as a semipermeable membrane in fluorous reactions
- Brendon A. Parsons,
- Olivia Lin Smith,
- Myeong Chae and
- Veljko Dragojlovic
Beilstein J. Org. Chem. 2015, 11, 980–993, doi:10.3762/bjoc.11.110
- : perfluorinated solvents; phase screen; PTFE; semipermeable membrane; synthesis design; Introduction Fluorous reactions are a relatively new addition to the portfolio of synthetic methods [1][2][3][4][5]. In a fluorous triphasic reaction, introduced by Curran in 2001, a fluorous phase screen was used to
- may be warranted. Conclusion To better understand how PTFE tape functions as a semipermeable membrane, we examined its behavior and compared it to bulk PTFE. We included both simple diffusion processes and chemical reactions to examine the effects of solvents and reagents on the permeability of the
Graphical Abstract
Figure 1: PV-PTFE reaction design.
Figure 2: Solvent uptake in the delivery of bromine into dichloromethane (a) 0 min, (b) 0.50 min, (c) 0.83 mi...
Figure 3: Solvent column heights of bromine delivery into dichloromethane (○) and ethyl acetate. (♦).
Figure 4: Reproducibility of bromine delivery into a) dichloromethane and b) ethyl acetate. In each case thre...
Figure 5: Height of the solvent column in the course of the bromination of cyclohexene in (a) dichloromethane...
Figure 6: Height of the solvent column in the course of the bromination of cyclohexene in ethyl acetate (♦) a...
Figure 7: Solvent uptake when the delivery tube is inserted to a shallow depth. The solvent uptake stopped on...
Scheme 1: Iodolactonization of unsaturated diester 1 with iodine monochloride in dichlormethane.
Figure 8: (a) The delivery tube is immersed into the solution and there is a considerable solvent uptake. (b)...
Figure 9: Transport of dyed dimethyl phthalate in dichloromethane after (a) 0 h, (b) 1 h, (c) 2 h, (d) 3 h an...
Figure 10: Transport of dyed dimethyl phthalate in ethyl acetate after (a) 0 h, (b) 0.17 h, (c) 1 h, (d) 3 h, ...
Scheme 2: Chemiluminescence reaction of diaryl oxalate esters oxidized by hydrogen peroxide in the presence o...
Figure 11: When the diaryl oxalate was oxidized by aqueous peroxide solution, chemiluminescence was observed o...
Figure 12: Progression of PV-PTFE chemiluminescence with aqueous peroxide solution in the vial after (a) 10 mi...
Figure 13: Progression of PV-PTFE chemiluminescence with acetonitrile–aqueous peroxide solution in the vial af...
Figure 14: Diffusion of dimethyl phthalate assisted by tert-butanol through PTFE was visualized in a chemilumi...
Figure 15: Corrosion of aluminum resulting from bromine applied directly to metal.
Figure 16: Discoloration of aluminum from bromine applied to PTFE tape on metal.
Figure 17: After stirring bars were cut open, some iron bars were found to be corroded.
Figure 18: (a) Diffusion of bromine through a bulk PTFE from stirring bar into dichloromethane after 2 h. (b) ...
Figure 19: Diffusion of bromine through a PTFE tube.
Figure 20:
(a) The reaction of benzene and bromine in the absence of a stirring bar (![[Graphic 1]](/bjoc/content/inline/1860-5397-11-110-i3.png?max-width=637&scale=1.18182)
), in the presence of a n...
Camera-enabled techniques for organic synthesis
- Steven V. Ley,
- Richard J. Ingham,
- Matthew O’Brien and
- Duncan L. Browne
Beilstein J. Org. Chem. 2013, 9, 1051–1072, doi:10.3762/bjoc.9.118
- coloured solvent. By counting the relative proportion of red to white regions, the amount of gas in the solution could be quantified (Figure 21). The approach was then used to demonstrate that the same semipermeable membrane could be used in a second device to efficiently remove excess unreacted hydrogen
Graphical Abstract
Figure 1: The evolution of computer-based monitoring and control within the laboratory of the future. (a) In ...
Figure 2: A selection of the wide range of digital camera devices available, focusing on those that can be at...
Figure 3: (a) Network cameras (Linksys WVC54GC) in operation in the Innovative Technology Centre laboratory. ...
Figure 4: Remote transmission of video imagery and reaction monitoring data.
Figure 5: A camera can assist the chemist in a number of ways. Digital video recordings of reactions can be u...
Figure 6: Suzuki–Miyaura reaction performed within a microfluidic system. The product is observed by high-spe...
Figure 7: Friedel–Crafts reactions performed by using solid-acid catalysis at high pressures. A camera allowe...
Figure 8: (a) The video camera setup providing a view of the reaction within the microwave cavity; (b) a pall...
Figure 9: (a) Buchwald–Hartwig coupling within a microchannel reactor. (b) Camera view of aggregate deposits ...
Figure 10: The key diprotected piperazic acid precursor in the synthesis of chloptosin.
Figure 11: (a) Piperazic acid mixture, and (b) apparatus for enantiomeric upgrading by recorded crystallisatio...
Figure 12: (a) Crystallisation of a Mn(II) polyoxometalate. (b) A bespoke reactor produced using additive fabr...
Figure 13: Computer processing of digital imagery produces numerical data for later processing.
Figure 14: (a) The Morphologi G3 particle image analyser, which uses images captured with a camera microscope ...
Figure 15: Use of the Python Imaging Library to analyse the proportion of an image consisting of red pixels. A...
Figure 16: (a) Arduino [73,75], a flexible open-source platform for rapidly prototyping electronic applications. (b) ...
Figure 17: Patented device incorporating a standard 96-well plate illuminated by a white-light source. The pla...
Figure 18: Simple colour-change experiments to assess a new AF-2400 gas permeable flow reactor. The reactor co...
Figure 19: (a) Ozonolysis of a series of alkenes using ozone in a bottle-reactor; (b) Glaser–Hay coupling usin...
Figure 20: (a) Camera-assisted titration of ammonia using bromocresol green. NH3 is dissolved in the gas-flow ...
Figure 21: (a) Bubble-counting setup. As the output of the gas-flow reactor (hydrogen dissolved in dichloromet...
Figure 22: Usage of digital cameras to enable remote control of reactions.
Figure 23: In-line solvent switching apparatus. The reactor output is directed into a bottle positioned on a h...
Figure 24: Catch and Release apparatus. (1) The amide intermediate is sequestered onto the central sulfonic ac...
Figure 25: Clips from video footage showing the silica reagent changing appearance; the arrows indicate the ed...
Figure 26: Combination of computer vision and automation to enable machine-assisted synthetic processes.
Figure 27: A coloured float at the interface between heavy and light solvents allows a camera to recognise the...
Figure 28: Graphical demonstration of the image-recognition process. At the start of the experiment, the colou...
Figure 29: Application of the computer-vision-enabled liquid–liquid extractor. The product mixture of a hydraz...
Figure 30: Application of a computer-vision technique to measure the dispersion of a plug of material passing ...
Figure 31: Multiple extractors in series controlled by a single camera.
Figure 32: Two-step synthesis of branched aldehydes from aryl iodides using two reactive gases. A liquid–liqui...
