Efficient 1,3‐Oxazolidin‐2‐one Synthesis through Heterogeneous Pd^II‐Catalyzed Intramolecular Hydroamination of Propargylic Carbamates

Abstract

Herein, we present an operationally simple protocol for the cycloisomerization of propargylic carbamates in which a heterogeneous catalyst consisting of Pd species immobilized on amino‐functionalized siliceous mesocellular foam (PdII‐AmP‐MCF) is used. This Pd nanocatalyst displayed high efficiency at low catalyst loading and reaction temperatures, which allowed for the efficient and mild synthesis of a wide range of 1,3‐oxazolidin‐2‐one derivatives and related compounds. Moreover, it proved possible to re‐use the Pd nanocatalyst for several reactions, although a gradual decrease in activity was observed in the subsequent cycles.

Copper(II)‐Catalyzed Aminohalogenation of Alkynyl Carbamates

“…After 24 hours the solvent was removed under reduced pressure. The characterization of products 1 a , b , e , h , j , [15] and 1 c , i [16] are consistent with those reported in the literature.…”

Lanthanide Mimicking by Magnesium for Oxazolidinone Synthesis

“…These methods predominantly employ transition metal-based catalysts like Ir, Pd, or coinage metals, lanthanides. [7][8][9][10][11][12][13] The interest in developing environmentally friendly and safer synthesis methods for industrial processes is steadily increasing. The abundant presence of magnesium in the Earth's crust has led to a surge in research on its application in catalytic processes, with notable contributions from research groups such as Harder, Hill,Parkin,Okuda,Rueping,Milstein,Sadow,Schäfer,Pucheault,Nembenna,Venugopal, Despite the growing use of magnesium complexes in catalysis over the past decade, their utilization has primarily been limited to hydrofunctionalization reactions involving unsaturated bonds like aldehydes, ketones, alkenes, alkynes, carbodiimides, and isocyanates.…”

“…Additional methods, such as amide activation, cyclization of 2‐vinyl aziridines, intermolecular aminohydroxylation, and carbonylation of propargylic amines, have been reported. These methods predominantly employ transition metal‐based catalysts like Ir, Pd, or coinage metals, lanthanides [7–13] …”

Rare-Earth-Metal-Complex-Catalyzed Hydroalkoxylation and Tandem Hydroalkoxylation/Cyclohydroamination of Isocyanates: Synthesis of Carbamates and Oxazolidinones

“…In 2015, Liu and co-workers reported ruthenium-complex-catalyzed domino reactions between propargylic alcohols and tosyl isocyanates to produce oxazolidinone derivatives . Very recently, a heterogeneous catalytic version consisting of a Pd species (Pd II -AmP-MCF) and NaOAc (0.1 equiv) was employed in the intramolecular cyclohydroamination of propargylic carbamates . It should be noted that lanthanide catalysts have never been used in this reaction.…”