Solvent-Assisted Catalysis: Water Promotes Ring Closure Formation of 2‑Oxazolidinone from Amino Acid Derived N‑Boc-Epoxide.

Oxazolidinones are important heterocyclic compounds with several therapeutic properties, especially antimicrobial activity, as seen in linezolid. Unexpectedly, a 2-oxazolidinone structurally similar to linezolid was obtained, prompting optimization of the reaction methodology and quantum calculations to rationalize the experimental observation. The reaction proceeded efficiently in refluxing water, in which computational analysis identified a remarkable and unprecedented stable reaction intermediate, enabling possible anchimeric assistance. Water significantly accelerates the process by lowering energy barriers and facilitating epoxide ring-opening through hydrogen bonding catalysis, as supported by density functional theory calculations.