Incorporating open-source software components (Python, OpenCV), a computer-vision system was used to control the interface level in a gravitybased inline liquid-liquid separation device. This was used in the continuous flow bromination of a series of enaminone substrates. The main byproduct of the reaction, succinimide, was efficiently extracted into the aqueous stream, providing clean products without the need for further purification.

Please cite this article as: O'Brien, M., Cooper, D.A., Dolan, J., Continuous flow iodination using an automated computer-vision controlled liquid-liquid extraction system., Tetrahedron Letters (2017), doi: http://dx.doi.org/ 10. 1016/j.tetlet.2017.01.029 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Graphical AbstractTo create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Continuous flow iodination using an automated computer-vision controlled liquid-liquid extraction systemMatthew O'Brien,* Dennis A. Cooper and Jonathan Dolan Leave this area blank for abstract info. Staffordshire, ST5 5BG, UK. Over the last decade or so, flow chemistry has emerged as an alternative model to more traditional batch approaches to synthesis.1 In addition to offering significant safety benefits when using hazardous reagents, intermediates or conditions, 2 flow chemistry often enables superior control over interfacial exchange parameters 3 leading to highly efficient and scaleinvariant chemical processes. A particularly attractive feature of flow chemistry is the ability to incorporate in-line purification techniques. The use of solid-supported scavengers 4 and phaseswitching reagents have enabled many noteworthy flow syntheses. 5 In-line liquid-liquid extraction is also emerging as an alternative approach. Whilst it has limitations (obviously relying on efficient extraction from one phase to another) it can also offer advantages. Firstly, solid-supported reagents are often much more expensive than the equivalent soluble form. 6 Secondly, unless some regeneration protocol is incorporated into the system, solid-supported reagents become depleted over time and at some point will need replacing, possibly requiring the system to be temporarily shut down. Liquid extractants, which can be pumped continuously into the system, do not suffer from this issue. The use of solid supports also causes significant scaledependent dispersive effects.7 Whilst there will also be unavoidable dispersive effects associated with liquid-liquid extraction processes these can, in principle, be rendered scaleinvariant. Semi-permeable hydrophobic membranes, particularly those based on expanded PTFE, 8 have been used to effect continuous flow separation of aqueous and organic flow streams. 9 An alternative approach, essentially a flow adaptation of the traditional separating funnel, relies on the vertical separation of immiscible liquids under gravity. If a flow stream containing a mixture of two immiscible liquids is fed into a separating vessel with ...

Please cite this article as: O'Brien, M., Cooper, D.A., Mhembere, P., The continuous-flow synthesis of carbazate hydrazones using a simplified computer-vision controlled liquid-liquid extraction system, Tetrahedron Letters (2016), doi: http://dx.doi.org/10.1016/j.tetlet. 2016.10.018 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Tetrahedron LettersThe continuous-flow synthesis of carbazate hydrazones using a simplified computervision controlled liquid-liquid extraction system. --- Corresponding author. e-mail: m.obrien@keele.ac.ukIn recent years, the emergence of continuous flow methodology has created new opportunities for chemical synthesis. 1 Compared with traditional batch processes, flow methods can often offer significant safety benefits, particularly for transformations involving hazardous conditions or reagents.2 Additionally, the small dimensional scales involved lead to the efficient and scaleinvariant interfacial transfer of energy and matter.3 A particularly attractive aspect of flow chemistry is the ability to incorporate inline purification stages. Solid-supported scavengers 4 and phaseswitching protocols have been extremely successful in this regard. 5 However, solid-supported chemicals can often be much more expensive than their solution phase counterparts. 6 In addition, they often give rise to significant and scale-dependent dispersion effects 7 and become depleted over time, thus requiring replacement or regeneration. This can be a time consuming operation which usually necessitates halting of the flow process. As liquids can be continuously pumped through the system, inline liquid-liquid phase separation does not suffer from this problem and, whilst dispersion cannot be eliminated, it can be controlled and rendered scale invariant.One general method of inline liquid-liquid separation used in continuous flow makes use of the selective wetting of certain materials, particularly expanded porous PTFE membranes, to separate aqueous and organic solutions. 8 We have been interested, however, in gravity-based separations of immiscible liquids based on their densities.9 This is essentially a continuous flow adaptation of the classical separating funnel. The basic concept is shown in Figure 1. A biphasic stream of immiscible liquids with differing densities will, when passed into a suitable vessel, separate vertically. The dense phase will exit the vessel through a lower exit and the light phase will exit the vessel through an upper exit. In Figure 1 the organic phase is the dense phase and the aqueous extractant is the light phase, although these roles could be switched if less dense o...

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ABSTRACT:Combining the desymmetrization of a prochiral bis-hydroxymethyl group with the epimerization of a chiral furanyl ether in a single transformation, high levels of double diastereoselectivity have been achieved in a synthesis of 2,4,5-trisubstituted tetrahydropyrans which proceeds under thermodynamic control.