DOI
https://doi.org/10.1021/acs.jchemed.9b00310

Summary
In this paper a discovery-based nucleophilic aromatic substitution experiment that introduces chemistry students to micellar catalysis, green chemistry, and systems thinking is reported.
The experiment was performed by approximately 560 students in 30 different 4 h lab sections in first-quarter organic chemistry laboratory class.
The students, working in groups of two, set up three reactions. Two reactions included TPGS-750-M (a catalyst facilitates organic transformations in aqueous media) and varied only by the identity of the leaving group (fluoro vs bromo). A third reaction, used as a control reaction, did not include TPGS750-M.
A discovery-based approach, rather than an expository approach, was used to instruct the students. It was not assumed that the students were already familiar with SNAr chemistry. Instead, the chemistry was presented on the basis of mechanistic similarities to the reaction of nucleophiles with carboxylic acid derivatives.
Students’ feedback showed that the experiment helped them understand the effects leaving groups have in SNAr reactions and the importance of green chemistry. In their lab reports, they analyzed the mechanism and determined that the first step must be the rate limiting step and that the electronegativity of the fluorine stabilizes the Meisenheimer complex. Their comprehension of the principles involved was also demonstrated through an in-class quiz after the experiment and through the final exam.
In conclusion, the experiment described achieves multiple goals, including (1) using discovery-based methods to instruct students on leaving group effects in nucleophilic aromatic substitution reactions, (2) educating students on the importance of systems thinking and green chemistry, and (3) introducing students to the modern field of surfactant chemistry and micellar catalysis.

Relevance for Complex Systems Knowledge
The paper proposes an approach to reimagine higher education and deals with system thinking and green chemistry. The proposed experiment is appropriate for use in a second-year organic chemistry laboratory course and is useful to introduce students to how a systems thinking approach can allow them to focus not only on how high the yield is for a reaction but how a reaction fits into the larger picture of trying to care for the environment and how the choices made in determining how to perform a reaction can impact that larger picture.

Point of Strength
The point of strength of this paper is the design of a discovery-based nucleophilic aromatic substitution reaction that is performed in water using surfactants instead of organic solvents that are traditionally used in organic laboratory experiments.