Steps towards an efficient and sustainable catalytic process
It is reported that over 90% of chemicals are generated with the help of a catalyst and there is no doubt that metal catalysed reactions are integral to modern chemistry, especially in the role of developing sustainable technologies. However, meeting all the criteria of an efficient process; high conversion, low waste, catalytic rather than stoichiometric reagents and recyclable solvents and catalysts, is challenging and time-consuming. The steps described below can be used as a general guide to developing a catalytic process. While it has been written with transition-metal catalysis in mind, particularly the last 2 steps, the use of advanced experimental design is key to investigating all possible opportunities for the process, within manageable experiment numbers.
By now chemists are well aware of the considerable benefits of catalysts which include: reduced energy barriers, milder reaction conditions, the delivery of increasingly elaborate compounds, accessing previously inaccessible disconnections and the development of routes that otherwise wouldn’t work. The use of a catalyst may reduce process costs due to a reduction in operating temperatures and pressures and even cutting the plant time by enabling faster reactions as well as reducing the number of steps to make the product. While the use of a catalyst is included as one of the principles of green chemistry and can be thought of as sustainable, many of the most useful catalysts employed in the chemical industry are non-renewable precious metals which are expensive and require energy-intensive and highly wasteful mining techniques to produce. There may also be hesitation in implementing a catalytic process due to the complicated nature of its discovery and development and perhaps the perceived difficulty in removing the spent catalyst, particularly when a metal is involved. We can all agree that a catalytic 3-step process sounds more at ...