Synthesis of some new Rhodium complexes containing diaryl chalcogenide ligands and their uses as catalysts in hydrosilylation of alkenes

Diaryl Chalcogenides (i.e. Ar2E where Ar = 4-CH3C6H4, 4-BrC6H4, E= S, Se and Te) were reacted with [RhCl(CO)2]2 and rhodium(III) chloride trihydrate to give compounds of type [RhCl(CO)2(Ar2E)] and [RhCl3(Ar2E)3], respectively. All compounds were characterized by IR, NMR, and mass spectroscopic data. Attempts to prepare hydroxyapatite (HAp) supported rhodium catalyst by using different methods were unsuccessful. Complexes [RhCl(CO)2((4-R-C6H4)2S)], [RhCl(CO)2((4-R-C6H4)2Se)] and [RhCl(CO)2((4-R-C6H4)2Te), where R= CH3 or Br], were evaluated as catalysts for hydrosilylation of allyl phenyl ether and 1-decene. They showed good catalytic activities for hydrosilylation of alkenes with triethoxysilane.

Microwave-Assisted, One-Pot Synthesis of Doxycycline under Heterogeneous Catalysis in Water

The selective synthesis of active pharmaceutical molecules is a challenging issue, particularly when attempting to make the reactions even more sustainable. The present work focuses on the microwave-assisted hydrogenolysis of oxytetracycline to selectively produce α-doxycycline. Although the combination of microwave irradiation and a heterogeneous rhodium catalyst provided good conversions, the selective synthesis of active α-doxycycline was only achieved when an oxytetracycline-cyclodextrin complex was used as the starting material, giving the desired product at 34.0% yield in a one-step reaction under very mild conditions.

Asymmetric Hydrogenation for the Synthesis of 2-Substituted Chiral Morpholines

Asymmetric hydrogenation of unsaturated morpholines has been developed by using a bisphosphine-rhodium catalyst bearing a large bite angle. With this approach, a variety of 2-substituted chiral morpholines could be obtained...

Ruthenium-Catalyzed Room-Temperature Coupling of α-Keto Sulfoxonium Ylides and Cyclopropanols for δ-Diketone Synthesis

Previous transition metal-catalyzed synthesis of δ-diketones is plagued by high cost of rhodium catalyst and harsh reaction conditions. Herein a low-cost, room temperature ruthenium catalytic method is developed based on...