Oxo‐Rhenium(V) Complexes Containing Heterocyclic Ligands as Catalysts for the Reduction of Sulfoxides. Issue 9 (17th January 2014) - Sousa, Sara C. A.
Abstract: This work reports the catalytic activity of a large variety of oxo‐rhenium(V) complexes (1 mol‐%) containing the ligands 2‐(2‐hydroxy‐5‐methylphenyl)benzotriazole (Hhmpbta), 2‐(2‐hydroxyphenyl)benzothiazole (Hhpbt), 2‐(2‐hydroxyphenyl)benzoxazole (Hhpbo), and 2‐(2‐hydroxyphenyl)‐1 H ‐benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3 /[ReOBr2 (hmpbta)(PPh3 )] and pinacolborane/[ReOBr2 (hmpbta)(PPh3 )] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups. Abstract : Oxo‐rhenium complexes containing heterocyclic rings are efficient catalysts for the deoxygenation of aromatic and aliphatic sulfoxides using silanes and boranes as reducing agents.