Biocatalysis and green chemistry

The concepts of sustainable development and green chemistry are introduced and defined. Green chemistry metrics, notably E factors and atom economy (AE), together with environmental impact and sustainability metrics, such as the environmental quotient (EQ) and life cycle assessment (LCA), are discussed. The roles of solvents and catalytic versus classical chemical processes in determining the waste generated in chemical processes are delineated. The many attractive features of biocatalysis in the context of green chemistry are discussed: mild reaction conditions, employing a catalyst that is biodegradable and derived from renewable resources, and affording products of higher purity with better economics compared to conventional processes. This is illustrated by reference to four industrial examples: the synthesis of an intermediate for the cholesterol‐lowering agent, atorvastatin; the synthesis of two active pharmaceutical ingredients, pregabalin and sitagliptin; and, the synthesis of the perfumery ingredient, ambrafuran.