Atom economy

What is atom economy?

Atom economy measures the proportion of reactant atoms that end up in the desired product: (Mr of desired product / sum of Mr of all products) × 100%. Unlike percentage yield (which accounts for reaction efficiency), atom economy is a theoretical maximum based on stoichiometry. High atom-economy reactions are greener — fewer waste atoms. Addition reactions typically have 100% atom economy; substitution reactions produce by-products and have lower atom economy.