Learning without a Recipe: Double Functionalization of Phenylalanine

This activity proposes the functionalization of an amino acid at both its amino and carboxyl groups through a two-step synthesis. The activity constitutes a problem-solving exercise in which students are provided with a target molecule and a selection of initial reagents without any experimental procedure to follow. The task assigned to students is to first design the synthesis and then, step-by-step, perform the necessary reactions and purifications. In this guided process, students make decisions that, if correct, lead to the acquisition of the desired product. These decisions include the type of solvent and reagents to use, how to conduct workups and the product analysis. The process is semistructured with the implementation of guiding questions aimed at directing students’ reasoning toward that typical of an organic chemist. The problem-solving activity was tested with two classes of Italian upper secondary school students (aged 17–18). The procedure requires reagents and materials commonly found in all teaching laboratories and does not demand special safety precautions, even if students make technically incorrect choices. The activity was met with enthusiasm, allowing students to improve their comprehension of organic synthesis principles, thereby validating the effectiveness of the guided approach, since most of the students successfully completed the synthesis.