The Principles Of Green Chemistry – Eighth Principle: Reduce Derivatives

The Eighth Principle of Green Chemistry advocates for minimizing or avoiding unnecessary derivatization, such as using temporary blocking groups, due to the additional reagents and waste generation these steps require. A 'green' chemist should strive to design synthetic routes that eliminate or minimize these techniques.

While protecting groups are sometimes employed to modify a specific molecular function without deconstructing the entire molecule, their later removal demands more reagents, always results in some yield loss, and increases overall waste. By leveraging modern technologies, like selective catalytic reactions or enzymes, more direct synthetic pathways can be established, reducing the overall number of steps and improving process mass intensity (PMI).

A compelling industrial example is the synthesis of semi-synthetic antibiotics like ampicillin. The older method required a silyl protecting group and harsh, low-temperature reaction conditions. This has largely been replaced by a much cleaner, enzymatic process using pen-acylase in water at near-room temperature, eliminating the need for the protecting group entirely. Learn how adopting these strategies can enhance your synthetic processes.