A Mechanistic Insight on CuI-Catalyzed Synthesis of Oxazolidinones through a Four-Component Reaction

In this contribution, we describe a straightforward and efficient synthesis of oxazolidin-2-ones through a Cu(I)-catalyzed four-component coupling of amines, aldehydes, terminal alkynes, and CO2 via carboxylative cyclization of propargylamine intermediates. This strategy enables the selective synthesis of a variety of (Z)-5-alkylidene-oxazolidin-2-ones substituted in positions 3, 4 and 5 of the heterocyclic core with a variety of functional groups, well-tolerated in terms of scope. A mechanistic study was carried out monitoring the process in solution by different techniques (operando FTIR, multi-nuclear NMR), with the aim of identifying the intermediates, both organic compounds and Cu(I) coordination complexes, which showed the plausible multi-metallic nature of the catalytic intermediates (identified by X-ray diffraction analyses on monocrystal). image