One-Step Synthesis of 3,4-Disubstituted 2-Oxazolidinones by Base-Catalyzed CO Fixation and Aza-Michael Addition.

2-Oxazolidinones are saturated heterocyclic compounds, which are highly attractive targets in modern drug design. Herein, we describe a new, single-step approach to 3,4-disubstituted 2-oxazolidinones by aza-Michael addition using CO as a carbonyl source and 1,1,3,3-tetramethylguanidine (TMG) as a catalyst. The modular reaction, which occurs between a γ-brominated Michael acceptor, CO and an arylamine, aliphatic amine or phenylhydrazine, is performed under mild conditions.

Pyridinethiol-Assisted Dissolution of Elemental Gold in Organic Solutions.

Dissolution of elemental gold in organic solutions is a contemporary approach to lower the environmental burden associated with gold recycling. Herein, we describe fundamental studies on a highly efficient method for the dissolution of elemental Au that is based on DMF solutions containing pyridine-4-thiol (4-PSH) as a reactive ligand and hydrogen peroxide as an oxidant. Dissolution of Au proceeds through several elementary steps: isomerization of 4-PSH to pyridine-4-thione (4-PS), coordination with Au , and then oxidation of the Au thione species to Au simultaneously with oxidation of free pyridine thione to elemental sulfur and further to sulfuric acid.

Iron-Catalysed Selective Aerobic Oxidation of Alcohols to Carbonyl and Carboxylic Compounds.

A method for aerobic alcohol oxidation catalysed by Fe(NO ) /2,2'-bipyridine/TEMPO has allowed highly selective conversion of primary alcohols into either aldehydes or carboxylic acids in one-step. The oxidation of primary alcohols proceeded selectively to aldehydes, as TEMPO was present in the reaction. Nevertheless, the aldehydes were further oxidized into carboxylic acids as the reaction time was extended.