Why we might be misusing process mass intensity (PMI) and a methodology to apply it effectively as a discovery level metric

Edward Monteith, Pieter Mampuys, Louise Summerton, James Hanley Clark, Bert Maes, Rob McElroy

Research output: Contribution to journalArticlepeer-review


Process mass intensity (PMI) is a key mass-based metric to evaluate the green credentials of an individual or sequence of reactions during process and chemical development. The increasing awareness to consider greenness as early as the initial discovery level, requires a set of parameters suitable to assess it at this stage of development, and guidelines to apply them correctly. This paper evaluates when and how PMI can be used in a correct manner. Different simulations for key reactions in the organic synthesis toolbox – i.e. amide bond formation and Mitsunobu reactions – illustrate that PMI can easily be misleading without due consideration of yield, concentration and molecular weight of reactants and product. A fair appraisal of the green potential of different methodologies therefore requires careful analysis of the examples and metrics data generated.
Original languageEnglish
Pages (from-to)123-135
Number of pages13
JournalGreen Chemistry
Issue number1
Early online date7 Nov 2019
Publication statusE-pub ahead of print - 7 Nov 2019

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© The Royal Society of Chemistry 2020. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

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