4476-77-1Relevant articles and documents
A new organo-ruthenium substituted tungstotellurate: Synthesis, structural characterization and catalytic properties
Zheng, Da-Ming,Wang, Rui-Qiang,Du, Yu,Hou, Guang-Feng,Wu, Li-Xin,Bi, Li-Hua
, p. 8829 - 8836 (2016/10/11)
Reaction of [RuC6H6Cl2]2 with TeO2 and Na2WO4·2H2O in aqueous solution (pH 4.7) yielded a novel organo-ruthenium supported tungstotellurate polyanion, [Te2W20O70(RuC6H6)2]8- (Ru-1), which is composed of two [RuC6H6]2+ units linked to a [Te2W20O70]12- fragment through Ru-O(W) bonds resulting in an assembly with idealized C2h symmetry. Furthermore, the polyanion Ru-1 was anchored on 3-aminopropyltriethoxysilane (apts)-modified SBA-15 to prepare new catalysts (SBA-15-apts-Ru-1) containing different amounts of Ru-1, which were characterized using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2-adsorption measurement and Fourier transform infrared reflectance (FT-IR) spectroscopy. Finally, the catalytic activity of SBA-15-apts-Ru-1 was evaluated for the aerobic oxidation of n-tetradecane using air as the oxidant in the absence of any additives or solvents. In addition, the optimum catalytic reaction conditions were also determined.
Enantioselective addition of organozinc reagents to aldehydes catalyzed by 3,3′-bis(diphenylphosphinoyl)-BINOL
Hatano, Manabu,Miyamoto, Takashi,Ishihara, Kazuaki
, p. 1561 - 1568 (2007/10/03)
The enantioselective addition of organozinc reagents to aromatic and aliphatic aldehydes 1 gives secondary alcohols 2 with excellent enantioselectivities in high yields through the catalytic use of (R)-3,3′-bis(diphenylphosphinoyl)-BINOL (3) or (R)-3,3′- bis(diphenylthiophosphinoyl)-BINOL (4) without Ti(IV) complexes. The coordination of the O or S atom of a (thio)phosphinoyl group bearing a BINOL backbone to organozinc reagents can efficiently increase the nucleophilicity of the organozinc reagents.
Shape Selective Alkane Hydroxylation by Metalloporphyrin Catalysts
Cook, Bruce R.,Reinert, Thomas J.,Suslick, Kenneth S.
, p. 7281 - 7286 (2007/10/02)
A series of manganese and iron porphyrins with sterically protected pockets are shown to be shape selective alkane hydroxylation catalysts.With iodosobenzene as oxidant, good regioselectivity is observed for hydroxylation of alkanes at the least hindered methyl group by using the very sterically hindered (5,10,15,20-tetrakis(2',4',6'-triphenylphenyl)porphyrinato)manganese(III) acetate (MnTTPPP(OAc)) as catalyst; The moderately hindered (5,10,15,20-tetrakis(2',4',6'-trimethoxyphenyl)porphyrinato)manganese(III) acetate shows little selectivity toward terminal CH3 hydroxylation but does show enhancement for the adjacent, ω - 1, CH2 site.Primary selectivity is dependent on the size and shape of the alkane substrate, with more bulky substituents giving greater primary selectivity.Substituting pentafluoroiodosobenzene or m-chloroperbenzoic acid as oxidants yields similar selectivity, thus conclusively demonstrating metal based oxidation via a common intermediate for these three systems.In contrast, tert-butyl hydroperoxide or 2,2,2-trifluoroethanol solubilized pentafluoroiodosobenzene show no primary carbon selectivity, and reaction product ratios are independent of the metalloporphyrin catalyst; this demonstrates that the site of oxidation with these oxidants is not metal based.The iron porphyrin derivatives also show good primary selectivity, although to a lesser degree than with the Mn derivatives, proving that these oxidations too are metal based.The regioselectivities for alkane hydroxilation shown by TTPPP derivatives are comparable to or better than those found for some isozymes of cytochrome P-450 which are responsible for primary alcohol biosynthesis from steroids, fatty acids, and alkanes.
