Atom economy

Atom economy, or avoiding waste by incorporating as much of the starting materials into the desired products as possible...

...a concept introduced by Barry Trost of Stanford University, is a ratio that lets us know what percentage of the reactants' atoms make their way into the desired product.

Through my findings on the this subject online I understood how atom economy adds a special perspective to what chemists have traditionally considered a successful chemical reaction to be. This success was measured strictly by the percentage yield, with no attention to the wasted product (unincorporated and undesired) that doesn't even make its way into the usable yielded product.

This is fabulous that B. Trost has instigated an awareness of efficiency in the lab--calling attention to the waste (sometimes toxic) that has been mistakenly considered a part of the percentage yield for years. This gives me hope that there is a new consciousness forming among chemists.

I thought the following list in the article/lesson plan "Waste and Tinker Toys was helpful in further exploring what questions need to be asked in the labs:
* The nature of waste produced: Is the waste toxic or environmentally harmful?
* The amount of energy needed to make the reaction proceed: Does the reaction require excessive amounts of energy?
* The use of auxiliary reagents: Does the syntheses require solvents or the use of significant amounts of materials to extract or purify the product?
* The percent yield of the reaction: Is a high yield of the product obtained, or is most of the desired product lost as waste?
* The selectivity of the reaction: Is the desired product produced in considerable preference to unwanted side products?