Recycling studies. One of the most employed benchmarks for promptly evaluating a reaction's environmental viability is Sheldon's time-honored E Factor. However, alternative metrics including process mass intensity (PMI), notably, life cycle assessment (LCA) are increasingly gaining prominence. Recycling of aqueous reaction mixtures can have a significant impact on each of these parameters. Thus, following an initial reaction between naphthalen-1-yl sulfurofluoridate (1a) and 4aminoacetophenone (1b) (Scheme 10), the desired product 1 can be readily isolated using an in-flask extraction with minimal amounts of recyclable EtOAc (see SI, section 7). Subsequently, re-use of the aqueous phase remaining in the original reaction vessel for two additional cycles led to excellent yields of aminated product 1. Only additional catalyst, ligand, base, and starting materials need to be added, preferably under inert atmosphere, after each coup- ling. Overall, these three reactions required a total investment of only 0.25 mol % Pd per amination. After the 3 rd reaction (2 nd recycle), salt buildup increased viscosity to the point where additional usage of the aqueous reaction mixture was precluded. E Factors associated with this recycling were 2.5 (when recyclable EtOAc is not considered waste; see SI section 7) and 17 (when EtOAc is not recycled). These values compare very favorably with typical E Factors associated with the pharmaceutical industry that vary, according to Sheldon, 47 between 25 and 100, without inclusion of water in the calculation.