JultikaUniversity of Oulu repository

Abstract

Green chemistry provided a new focus point on future innovations in the chemical enterprise. The aim was to design intrinsically safer chemicals and processes for chemistry used in the production of myriad aspects of everyday life. Green chemistry is often defined by the 12 principles of green chemistry compiled in 1998 by Anastas and Warner. Still, quantifying “greenness” for chemistry remained complicated. There are multiple green chemistry metrics and evaluation tools available. However, with no standardised measurement baselines or agreed upon standard metrics to use, the definition of green chemistry remains vague.

Furthermore, modes of operation to gather all data required for a comprehensive greenness evaluation might not even exist yet. Historically, the research of environmental or health effect of chemicals was continuously slower than the invention of new chemicals. Now, with the need for new greener chemistry innovations, it would be important to have reliable methods for evaluating and comparing different options under consideration. Green chemistry needs to be defined and quantified in greater detail. However, this is not straightforward, as green chemistry might need to be a customised solution for every reaction and requires compromises between different environmental and health hazards.

This thesis presented selected green chemistry metrics that were considered useful for comparing organic synthesis routes in a small laboratory scale. These were atom economy, E-factor, Process Mass Intensity (PMI), Reaction Mass Efficiency (RME), Green Aspiration Level (GAL), EcoScale, Greenness Index and Life Cycle Assessment (LCA). A few of the reviewed metrics were applied in a case study comparing two reaction pathways: Suzuki-Miyaura coupling and palladium catalysed direct arylation. The case study included atom economy, RME, simple E-factor (sEF) and a partial EcoScale analysis. Simple E-factor seemed like the easiest, most promising addition to use for comparing reaction paths in the development phase of a new molecule. It would add waste formation into the considerations of yield and time efficiency of a reaction.