On the use of "green" metrics in the undergraduate organic chemistry lecture and lab to assess the mass efficiency of organic reactions

A general analysis of reaction mass efficiency and raw material cost has been developed using an Excel spreadsheet format that can be applied to any chemical transformation. Reaction mass efficiency is a quantity that can be factored into four independent factors: reaction yield, atom economy, inverse of stoichiometric factor accounting for the use of excess reagents, and materials recovery parameter accounting for the use of reaction solvents, catalysts, and other materials used in post-reaction operations such as workup and purification procedures. Results are depicted in the style of a tax form and as a radial pentagon that allow the easy visual inspection of which variables contribute to the attenuation of reaction mass efficiency for a given reaction. The effect of various recovery scenarios may also be analyzed. These new methods may be easily incorporated into standard laboratory exercises and lab report write-ups in undergraduate organic labs to assess the greenness" of student experiments."