Process synthesis methodology chapter

Initial work on the design of structured products has been presented by, for example, Meeuse et al. 2000, Wibowo and Ng, 2001, 2002. In this chapter a real life example of a process redesign project where process synthesis techniques were applied to a structured food product, is presented. First, we position this work in the framework of integrated product and process design. Then we describe how we translated existing process synthesis techniques into a useful methodology for structured products. Then the actual case study is presented. Finally some perspectives are given. 

The example presented in section 6.4 of this chapter showed that process synthesis can be applied to structured food products. Moreover this application is of true value since significant cost savings could be achieved. However, a complete methodology is not yet available. One of the main outstanding questions is how to perform the identified (necessary) tasks in an optimal sequence to obtain the desired product Besides this the success of application depends critically on the availability of domain knowledge about all relevant aspects of the process. Several factors relevant for food processing were not considered in this example ... 

Many of the examples mentioned have been directly concerned with, or have a consequential importance, to the area of parallel high throughput chemical processing. Any methodology that offers the ability to accelerate the synthesis of large chemical libraries or to access new chemical entities in a clean fashion needs careful consideration. It is certainly true that we have only just begun to comprehend and contemplate the possibilities that the combination of these two powerful technologies could offer. It is therefore hoped that this short chapter will in some way stimulate you, the reader, to have a new outlook on these synthetic methods. 

Although providing only comparative and not absolute values, the methodology of eco-efficiency is very useful for an evaluation of process alternatives. In Chapter 1 (Section 1.6.1), Table 1.10 summarizes the results of a study by EuropaBio to evaluate the contribution of biotechnologies to sustainability. One of the dted examples is the synthesis of vitamin B2, an essential nutrient found in meat, dairy foods, plant foods and corn products and which is required by the body to break down food components, maintain tissue and absorb other nutrients. Using the eco-efficiency and, particularly, the portfolio plot it is possible to further demonstrate the benefits... 

In this Chapter, for the purpose of the prevention of the environmental pollution and the simplification of surface grafting process, the radical graft polymerization of vinyl monomers onto silica nanoparticle and carbon black surfaces by "grafting onto" and "grafting from" process in an ionic liquid will be reviewed. In addition, the grafting of hyperbranched poly(amidoamine) (PAMAM) onto silica nanoparticle surface by dendrimer synthesis methodology in an ionic liquid will be discussed. 

Real-time synthesis of operating procedures. Most of the ideas and methodologies, presented in this chapter, are applicable to the a priori, off-line, synthesis of operating procedures. There is a need though to address similar problems during the operation of a chemical plant. Typical examples are the synthesis of operational response (i.e., operating procedure) to process upsets, real-time recovery from a fallback position, and supervisory control for constrained optimum operation. 

The reactions presented in this chapter show clearly that enzyme-triggered domino reactions offer a great potential in asymmetric synthesis. It remains to be seen, whether this methodology becomes a general tool, since the design of such enzyme-induced domino processes is not trivial. Nonetheless, this emerging field obviously has great potential. 

Abstract In this chapter different types of domino-processes are described which consist of the combination of cationic, anionic, radical, pericyclic and transition metal-catalyzed as well other reactions. The methodology is used for the highly effective synthesis of carbocycles and heterocycles as well as of natural products and other interesting materials. It is also employed as an efficient tool in combinatorial chemistry. 

Continuing with the approach of this chapter from previous years metal-mediated reactions, cycloadditions, radical processes and asymmetric applications will be highlighted. Syntheses using traditional approaches will not be covered, unless improvements are reported. Due to the volume of publications concerning pyridines and associated heterocycles many subject areas could not be covered. Combinatorial or solid-phase synthesis will not represented since the area is rather specialized and many of the processes utilize existing methodology. The synthesis and reactions of polyaza-fused systems of the pyridine class will also not be included in this review. 

It should be mentioned that the great majority of dynamic kinetic resolutions reported so far are carried out in organic solvents, whereas all cyclic deracemizations are conducted in aqueous media. Therefore, formally, this latter methodology would not fit the scope of this book, which is focused on the synthetic uses of enzymes in non-aqueous media. However, to fully present and discuss the applications and potentials of chemoenzymatic deracemization processes for the synthesis of enantiopure compounds, chemoenzymatic cyclic de-racemizations will also be briefly treated in this chapter, as well as a small number of other examples of enzymatic DKR performed in water. 

Although nature has been the primary source of the proteinogenic amino acids through extraction processes, many of the unnatural analogues have to be synthesized. Modem asymmetric synthetic methodology is now in the position to provide cheap, pure, chiral materials at scale. Some of the unnatural amino acids are now made at scale and have been used to extend the chiral pool. To avoid duplicating sections of this book, this chapter discusses the problems associated with the synthesis of unnatural amino acids at various scales. This illustrates that a single, cheap method need not fulfill all of the criteria to provide a chiral pool material to a potential customer, and a number of approaches are required. 

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