Optimizing an Organocatalyzed Process in an Undergraduate Laboratory: A Solvent Screening

In this undergraduate organic laboratory study, extensive solvent screening was meticulously designed for the optimization of the l-proline-organocatalyzed intermolecular aldol reaction involving acetone and p-nitrobenzaldehyde. The experimental procedure entailed selecting specific solvents, analyzing the reaction crude through NMR spectroscopy, and subsequently, purifying the aldol adducts to measure their enantiomeric ratios via HPLC provided with the chiral column. Remarkably, this comprehensive investigation was efficiently conducted within two concise 2-h laboratory sessions, together with a 1-h seminar session, rendering it highly suitable for both Bachelor’s and Master’s degree programs. Conducted at room temperature, the experiments unveiled significant variations in both yields and enantiomeric excess of the aldol products and the byproducts proportions, depending on the solvent of choice. This experiential learning opportunity empowers students to gain practical insights into organocatalyzed transformations, purification techniques, and chromatographic analysis, enhancing their proficiency as organic chemists.