Metrics

Metrics can be used to guide reaction discovery to design an effective and inherently green methodology.  Highlighting potential issues as early as possible in discovery stage will allow problems to be addressed earlier in the development process.  In order to assess the greenness of a reaction or process, quantitative and qualitative metrics should be employed. There are a multitude of metrics available in the literature that can be used to measure, compare and assess methodologies and difficulty often arises when deciding which metrics to use.  Rather than viewing one step or substance in isolation, or focussing solely on mass based metrics, it is essential that a holistic viewpoint is taken, considering a full range of issues.  This is to ensure that a balance is struck and the best possible outcome for the methodology as a whole is found.  

Learning Objectives

By the end of this module you should:

• Understand the importance of adopting a holistic approach to assessing the greenness of a reaction and the limitations of focussing solely on mass based metrics;
• Understand how metrics can be used to work towards greener and more sustainable solutions by:
  • Identifying hot spots/areas of concern;
  • Identifying where reactions are performing well in terms of their greenness;
  • Facilitating benchmarking – obtaining a baseline against which to compare new methods;
• Be able to think critically about sustainability and environmental acceptability, by analysing advantages and disadvantages of synthetic routes.