Biomimetic iron(iii) complexes of facially and meridionally coordinating tridentate 3N ligands: tuning of regioselective extradiol dioxygenase activity in organized assemblies
lower amount (18.3%) of the intradiol cleavage products (E/I, 3 : 1). Remarkably, in aqueous SDS micellar media, it shows exclusive extradiol cleavage products (79.4%) while all the other complexes show very low selectivity (E/I: 1, 0.03 : 1; 2, 79.4 : 0, 3, 0.06 : 1, 4, 0.06 : 1), suggesting the suitability of SDS medium for 2 to elicit exclusive extradiol cleavage. The TX-100 micellar medium also provides
pH-metric titration studies in methanol disclose that the ligand in [Fe(HL)(DBC)]+ is protonated. The [Fe(L)(DBC)] adducts of iron(III) complexes of bis(pyridyl)-based ligands (1,2) afford higher amounts of intradiol-cleavage products, whereas those of mono/bis(imidazole)-based ligands (4,5) yield mainly the auto-oxidation product benzoquinone. It is remarkable that the adducts [Fe(HL)(DBC)]+/[Fe(HL3)(DBC)X]
Rhodium(I)-Catalyzed Decarbonylative Aerobic Oxidation of Cyclic α-Diketones: A Regioselective Single Carbon Extrusion Strategy
作者:Gangadhararao Golime、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.7b03837
日期:2018.2.16
rhodium-catalyzed decarbonylative aerobic oxidation of cyclic α-diketones has been developed for the first time, where the regioselective formations of α-pyrones and isocoumarins have been achieved. The current decarbonylative aerobic oxidation pathway proceeds via the C–C bond cleavage followed by a C–O bond formation, representing a biomimetic oxidation approach to unsaturated six-membered cyclic
Catalytic and regiospecific extradiol cleavage of catechol by a biomimetic iron complex
作者:Sayanti Chatterjee、Debobrata Sheet、Tapan Kanti Paine
DOI:10.1039/c3cc44124e
日期:——
ligand reacts with dioxygen in the presence of ammonium acetate-acetic acid buffer to cleave the aromatic C-C bond of 3,5-di-tert-butylcatechol regiospecifically resulting in the formation of an extradiol product with multiple turnovers.
Effective oxygenation of 3,5-di-t-butylpyrocatechol catalysed by vanadium(III or IV) complexes
作者:Yoshitaka Tatsuno、Masanobu Tatsuda、Sei Otsuka
DOI:10.1039/c39820001100
日期:——
Oxygenation of 3,5-di-t-butylpyrocatechol (1) to the corresponding muconic acid anhydride (2) and 2-pyrone (3) is efficiently catalysed by vanadium(III or IV) complexes.