Auto-Tandem Catalysis in Ionic Liquids: Synthesis of 2-Oxazolidinones by Palladium-Catalyzed Oxidative Carbonylation of Propargylic Amines in EmimEtSO4

Abstract

A convenient carbonylative approach to 2-oxazolidinone derivatives carried out using an Department of Chemistry, University of Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy; ionic liquid (1-ethyl-3-methylimidazolium nicola.ethyl sulfate, EmimEtSO4 ) as the solvent is presented. It is based on the sequential concatenation of two catalytic cycles, both catalyzed by the same metal species (auto-tandem catalysis): the first cycle corresponds to the oxidative monoaminocarbonylation of the triple bond of Received: propargylic 16 June 2016; amines Accepted: to give 5 July 2016; the Published: corresponding date 2-ynamide intermediates, while the second one involves the cyclocarbonylation of the latter to yield 2-(2-oxooxazolidin-5-ylidene)-acetamides. Abstract: A convenient carbonylative approach to 2-oxazolidinone derivatives carried out using an Reactions areionic carried liquid out (1-ethyl-3-methylimidazolium using a simple catalytic ethyl system sulfate, EmimEtSO4) consisting as ofthe PdI solvent2 in conjunction is presented. It is with an excess of KI, and thebased catalyst/solvent on the sequential system concatenation could of two be recycled catalytic cycles, several both catalyzed times without by the same appreciable metal species loss of activity (auto-tandem catalysis): the first cycle corresponds to the oxidative monoaminocarbonylation of the after extraction of the organic product with Et2 O.