Highly Efficient β-Functionalized Oxidomolybdenum(V) Corroles for Catalytic Oxidative Bromination of Phenols at Room Temperature

Two new β-functionalized oxidomolybdenum(V) corroles, oxido[3-formyl-5,10,15-triphenylcorrolato]molybdenum(V) ( Mo-1 ) and oxido[3-dicyanovinyl-5,10,15-triphenylcorrolato]molybdenum(V) ( Mo-2 ) were synthesized and characterized by various spectroscopic techniques and electrochemical studies. Mo-2 manifests splitted B bands due to x and y polarizations and highly red shifted longest B and Q bands due to the electron-deficient nature of the dicyanovinyl group. EPR data showed that these complexes exhibit an axial compression with d_xy¹ configuration. DFT studies revealed that HOMO and LUMO orbitals are stabilized in Mo-2 relative to Mo-1 . Mo-1 exhibits two successive reversible reductions and two oxidation potentials in cyclic voltammetry. Surprisingly, Mo-2 exhibits three successive reversible reductions and two oxidations; the one extra reduction could possibly be due to the reduction of the dicyanovinyl moiety. The catalytic activities of Mo-1 and Mo-2 for the oxidative bromination of various phenols using H₂O₂-KBr-HClO₄ mixture in water have been explored and exhibited excellent activity at a very low catalyst loading of 0.0030 and 0.0028 mol%, respectively. Both synthesized β-functionalized Mo(V) corroles manifest much higher conversion and TOF (59801–71174 h⁻¹) for oxidative bromination of phenols relative to earlier reported meso-functionalized Mo(V) corroles (20781–61646 h⁻¹). Hence, Mo-1 and Mo-2 mimic vanadium bromoperoxidase (VBPO) and act as functional models for these catalytic applications. These catalysts were reused upto 3 cycles and showed conversion rate upto 82 % indicating their excellent thermal and chemical stabilities.     

An improved and robust scale-up process aided with identification and control of critical process impurities in darunavir ethanolate

Research on Chemical Intermediates - A robust and safe industrial process, including five isolations and drying steps for widely prescribed anti-HIV (protease inhibitor) drug darunavir ethanolate...     

Synthesis and antimicrobialactivity of 2‐alkylcarbamato‐2,3‐dihydro‐5‐propylthio‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides

Novel 2‐alkylcarbamato/thiocarbama‐to‐2,3‐dihydro‐5‐propylthio‐1H‐1,3,2‐benzodiazaphos‐phole 2‐oxides ( 4a–J ) were synthesized by cyclization of 4‐propylthio‐1,2‐phenylenediamine ( 3 ) with the corresponding dichlorophosphoryl carbamates/thiocarbamates ( 2a–J ) that were obtained by the addition of alcohols/thiols to isocyanatophosphoryl dichloride ( 1 ). The structures of the title compounds were confirmed by the ¹H, ¹³C, ³¹P NMR, and mass spectral studies. Some of these products were found to possess significant antimicrobial activity. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:336–340, 2000