Various Strategic Approaches

Each chemical fragment generated by the synthetic tree must possess chemical properties that are predictable and allow selective combination in only one of many possible modes. 

The next goal is to reduce molecular complexity. This is done by meeting the following goals 2 

Reduction of molecular size by disconnection of chains or appendages. 

Modification or removal of sites of unusually high chemical reactivity of instability. 

There are also certain transformations that are important adjuncts to these goals but do not simplify the molecule. Examples of these transformations are  

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These service value chain approaches involve combinations of external supply chains, internal value integrators, and various strategic approaches. This complexaggregated structure is thus better termed a service value network. 

In materials chemistry, nanoparticles of noble metals are an original family of compounds. Well-defined in terms of their size, structure and composition, zero-valent transition-metal colloids provide considerable current interest in a variety of applications. Here, the main interest is their application in catalysis. Zerovalent nanocatalysts can be generated in various media (aqueous, organic, or mixture) from two strategic approaches according to the nature of the precursor, namely (i) mild chemical reduction of transition-metal salt solutions and (ii) metal atom... 

It is instructive to follow the evolution of the strategic principles with an example of the total synthesis of estrone 128 (Scheme 3.33), as it can be regarded historically as one of the trial cases used to evaluate the effectiveness of various synthetic approaches.The first total synthesis of estrone, reported in 1948 by Anner and Mischner, involved 18 steps with an overall yield of 0.1 % (based on the starting material, m-bromoanisole). In 1958, Johnson s group accomplished the synthesis in 10 steps with a 4.2% yield based on 2-methoxytetralone 129. Finally, in 1965, Torgov and co-workers carried out a six-step synthesis, also based on 129, but in 25% yield. 

Figure 1.1 The strategic goal of sustainable development relies on practical approaches such as green chemistry, industrial ecology, and green engineering. These approaches use various operational tools (e.g., catalysis), and monitoring tools (e.g., life-cycle...

This chapter considers the specific physicochemical considerations of various chromatographic modes and provides strategic considerations in HPLC separations as well as heuristic approaches and productivity considerations in scale-up operations. 

The Natural Step Framework and approach are elaborated from the constraints determined by basic principles of sustainability. Backcasting from basic principles of sustainability is a framework that covers relevant aspects of how to plan ahead in a complex system, such as for societies within the biosphere. The approach brings a sustainability perspective to analyses of current practices and materials, suggested solutions and visions, and the strategic evaluation of various solutions and paths to arrive at sustainability. And it brings this new perspective in with opportunities for improved economic outcomes. 

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