Application of ReactArray Robotics and Design of Experiments Techniques in Optimisation of Supported Reagent Chemistry

DoE-Driven Development of an Organocatalytic Enantioselective Addition of Acetaldehyde to Nitrostyrenes in Water

The development of an enantioselective enamine‐catalysed addition of masked acetaldehyde to nitroalkenes via a rational approach helped to move away from the use of chloroform. The presented research allows the use of water as a reaction medium, therefore improving the industrial relevance of a protocol to access very important pharmaceutical intermediates. Critical to the success is the use of chemometrics‐assisted ‘Design of Experiments’ (DoE) optimisation during the development of the presented new synthetic approach, which allows to investigate the chemical space in a rational way.

Self-optimising processes and real-time-optimisation of organic syntheses in a microreactor system using Nelder–Mead and design of experiments

Comparing an enhanced simplex algorithm with model-free design of experiments, this work presents a flexible platform for multi-objective, real-time optimisation.

Applying Statistical Design of Experiments and Automation to the Rapid Optimization of Metal-Catalyzed Processes in Process Development

The application of automation in conjunction with DoE designs towards the rapid discovery and optimization of metal-catalyzed reactions used in the synthetic preparation of clinical drug candidates at Merck Process Research is demonstrated with three examples. A description of the software and hardware is provided, followed by three examples highlighting these applications. The first example highlights a DoE optimization of a platinum-catalyzed chemoselective hydrogenation of a nitroaromatic nitrile. In the second example, automated screening is employed to discover a highly efficient palladium catalyst that affects nitrostyrene cyclization under a carbon monoxide reducing atmosphere. In the last example, a rapid discovery and DoE optimization of a rhodium-catalyzed diastereoselective hydrogenation of an unsaturated ester is detailed.

The application of design of experiments (DoE) reaction optimisation and solvent selection in the development of new synthetic chemistry

This article outlines the benefits of using 'Design of Experiments' (DoE) optimisation during the development of new synthetic methodology. A particularly important factor in the development of new chemical reactions is the choice of solvent which can often drastically alter the efficiency and selectivity of a process. Whilst solvent optimisation is usually done in a non-systematic way based upon a chemist's intuition and previous laboratory experience, we illustrate how optimisation of the solvent for a reaction can be carried out by using a 'map of solvent space' in a DoE optimisation. A new solvent map has been developed specifically for optimisation of new chemical reactions using principle component analysis (PCA) incorporating 136 solvents with a wide range of properties. The new solvent map has been used to identify safer alternatives to toxic/hazardous solvents, and also in the optimisation of an S(N)Ar reaction.

Solid supported reagents in multi-step flow synthesis

The frequently overlooked benefits that considerably simplify and enrich our standard of living are most often hinged upon chemical synthesis. From the development of drugs in the ongoing fight against disease to the more aesthetic aspects of society with the preparation of perfumes and cosmetics, synthetic chemistry is the pivotally involved science. Furthermore, the quality and quantity of our food supply relies heavily upon synthesised products, as do almost all aspects of our modern society ranging from paints, pigments and dyestuffs to plastics, polymers and other man-made materials. However, the demands being made on chemists are changing at an unprecedented pace and synthesis, or molecular assembly, must continue to evolve in response to the new challenges and opportunities that arise. Responding to this need for improved productivity and efficiency chemists have started to explore new approaches to compound synthesis. Flow-based synthesis incorporating solid supported reagents and scavengers has emerged as a powerful way of manipulating chemical entities and is envisaged to become a core laboratory technology of the future.

A simple homemade reaction station for use in parallel solution-phase synthesis. Optimization of a regioselective one-step deprotective o-formylation reaction mediated by the Vilsmeier-Haack reagent POCl3.DMF

We report herein the fabrication of a simple and price-affordable portable reaction station for use in parallel solution-phase synthesis. This homemade device uses currently available laboratory components and equipment. Specifically designed to fit standard magnetic hotplates/stirrers, it can simultaneously hold up to 24 heated and magnetically stirred glass reactors of both 10 and 50 mL capacities. Glass reactors are connected by flexible 16-gauge metal needles to a central gas manifold equipped with an inlet/outlet for vacuum and inert gases. Reaction temperatures can be optimally varied from -78 ( composite function)C to 150 degrees C. Using a statistical screening DOE method, this parallel array reactor station has been successfully operated to optimize the one-step deprotective O-formylation of a sterically hindered bis-O-tert-butyldiphenylsilyl (O-TBDPS) aromatic diol. The latter transformation was mediated by the Vilsmeier-Haack reagent POCl3.DMF using a range of Lewis acid and metal salt promoters, including their binary combinations.

Application of statistical ‘design of experiments’ methods in drug discovery

The use of 'design of experiments' (DoE) is a revolutionary approach to optimisation and screening of experimental parameters. Simple experimental designs and statistical tools for data analysis can provide much information about the system under investigation after only a few experiments. Such information can be key in decision-making for further experiments and can enable the development of robust and reliable protocols for chemical synthesis, analytical methods or biological assays. Coupling of design of experiments with modern high-throughput automation systems has the potential to maximise the capabilities of these systems and give increased productivity for many drug discovery applications.

Process optimization using combinatorial design principles: parallel synthesis and design of experiment methods

The use of parallel synthesis techniques with statistical design of experiment (DoE) methods is a powerful combination for the optimization of chemical processes. Advances in parallel synthesis equipment and easy to use software for statistical DoE have fueled a growing acceptance of these techniques in the pharmaceutical industry. As drug candidate structures become more complex at the same time that development timelines are compressed, these enabling technologies promise to become more important in the future.