54884-84-3Relevant academic research and scientific papers
Site-Selective Mono-Oxidation of 1,2-Bis(boronates)
Yan, Lu,Morken, James P.
supporting information, p. 3760 - 3763 (2019/05/24)
Site-selective oxidation of vicinal bis(boronates) is accomplished through the use of trimethylamine N-oxide in 1-butanol solvent. The reaction occurs with good efficiency and selectivity across a range of substrates, providing 2-hydro-1-boronic esters which are shown to be versatile intermediates in the synthesis of chiral building blocks.
Direct, high-yielding, one-step synthesis of vic-diols from aryl alkynes
Ramachandran, P. Veeraraghavan,Drolet, Michael P.
supporting information, p. 967 - 970 (2018/02/14)
An unprecedented, high yielding, direct, one-step synthesis of vic-diols from alkynes has been developed via metal-free, open-to-air dihydroboration with ammonia borane. The electronics of the alkyne and the reaction stoichiometry are critical for obtaining optimal yields of the 1,2-diol.
Synthesis of heterodinuclear hemisalen complexes on a hexaarylbenzene scaffold and their application for the cross-pinacol coupling reaction
Miyasaka, Akihiro,Amaya, Toru,Hirao, Toshikazu
, p. 1615 - 1621 (2014/03/21)
Intermolecular cross-pinacol coupling reaction between aliphatic and aromatic aldehydes by using heterodinuclear hemisalen complexes 1cis with vanadium(V) and titanium(IV) on a hexaarylbenzene scaffold is reported. Our ligand design is based on the individual activation of two aldehydes by vanadium and titanium, which are positioned with a suitable space on the rigid scaffold. Ligands such as 1cis were synthesized by Diels-Alder addition and decarbonylation reaction, followed by condensation of dialdehyde 3cis with various aminophenols. The influence of the substituents on the ligands on the pinacol coupling reaction was investigated. As a result, the reductive coupling reaction between aliphatic and aromatic aldehydes by using a catalytic amount of 1cis in the presence of Me3SiCl and Zn provided the corresponding cross-coupled 1,2-diol in good yields with high cross-selectivity. Working together: Dihemisalen ligands on a hexaaryl benzene scaffold were designed and the heterodinuclear complexes 1cis with vanadium(V) and titanium(IV) were synthesized from the corresponding disalicylaldehyde compound (see scheme). By using the heterodinuclear catalysts, the selective intermolecular cross-pinacol coupling reaction between aliphatic and aromatic aldehydes is demonstrated. Copyright
Magnetically recoverable osmium catalysts with osmium-diolate esters for dihydroxylation of olefins
Fujita, Ken-Ichi,Umeki, Satoshi,Yasuda, Hiroyuki
, p. 947 - 950 (2013/07/19)
We prepared magnetically recoverable osmium catalysts with stable osmium-diolate esters and applied them to the dihydroxylation of olefins. By employing 2 mol% of the magnetic osmium catalyst, the dihydroxylation reaction proceeded smoothly to provide the corresponding vicinal diol with a low level of osmium leaching. After completion of the dihydroxylation, the osmium catalyst was readily recovered by use of an external magnet and was recycled up to five times. Georg Thieme Verlag Stuttgart . New York.
Homogeneous dihydroxylation of olefins catalyzed by OsO4 2- immobilized on a dendritic backbone with a tertiary nitrogen at its core position
Fujita, Ken-Ichi,Inoue, Kensuke,Tsuchimoto, Teruhisa,Yasuda, Hiroyuki
, p. 1594 - 1598 (2013/02/23)
OsO42- immobilized on a poly(benzyl ether) dendrimer with a tertiary nitrogen at its core position efficiently catalyzed the homogeneous dihydroxylation of olefins with a low level of osmium leaching. The dendritic osmium catalyst could be applied to the wide range of olefins. Furthermore, the dendritic osmium catalyst was recovered by reprecipitation and then reused up to five times.
Magnetically recoverable osmium catalysts for dihydroxylation of olefins
Fujita, Ken-Ichi,Umeki, Satoshi,Yamazaki, Manabu,Ainoya, Taku,Tsuchimoto, Teruhisa,Yasuda, Hiroyuki
experimental part, p. 3137 - 3140 (2011/06/28)
We prepared magnetically recoverable osmium catalysts by use of magnetite, quaternary ammonium salts, and potassium osmate(VI), and applied them to the dihydroxylation of olefins. By employing 2 mol% of the magnetic osmium catalyst, the dihydroxylation reaction proceeded smoothly to provide the corresponding vicinal diol in a good chemical yield. The osmium catalyst was readily recovered by use of an external magnet, and was reused repeatedly.
Guanidinium-based phosphotungstates and ionic liquids as catalysts and solvents for the epoxidation of olefins with hydrogen peroxide
Gharnati, Loubna,Walter, Olaf,Arnold, Ulrich,Doering, Manfred
experimental part, p. 2756 - 2762 (2011/08/02)
Several penta- and hexaalkylated guanidinium-based ionic liquids (GILs) were tested as solvents for the epoxidation of cyclooctene using the Venturello catalyst, [(C8H17)3N(CH3)] 3[PO4{WO(O2)2}4], and hydrogen peroxide as the oxidant. Epoxide yields were obtained in a broad range between 13 and 79 % depending on both the anion and the substituents on the guanidinium moiety. Recycling experiments showed that the catalyst can be used at least three times. Furthermore, new guanidinium phosphotungstates with the PW12O403- anion were synthesized and characterized. Their catalytic performance was evaluated, and GILs as well as acetonitrile were employed as the solvent. Results were compared to those obtained with the comparable ammonium-based catalysts [NR4] 3[PW12O40] (R = C4H9, C6H13) and the analogous imidazolium-based catalyst [BMIM]3[PW12O40] containing the 1-butyl-3-methylimidazolium cation. Employing different GILs as solvents, similar results were obtained for the guanidinium and imidazolium catalysts but significantly lower epoxide yields were obtained using the ammonium catalysts. On using acetonitrile as the solvent, guanidinium-based catalysts exhibited a better performance than the imidazolium catalyst in the case of linear and branched olefins and vice versa in the case of cyclic olefins. Several guanidinium phosphotungstates and guanidinium-based ionic liquids have been synthesized and characterized. Their catalytic performance in epoxidation reactions with hydrogen peroxide was evaluated and compared to similar ammonium and imidazolium compounds. The reaction systems can be recycled and used in at least three consecutive reactions. Copyright
A recyclable dendritic osmium catalyst for homogeneous dihydroxylation of olefins
Fujita, Ken-Ichi,Yamazaki, Manabu,Ainoya, Taku,Tsuchimoto, Teruhisa,Yasuda, Hiroyuki
experimental part, p. 8536 - 8543 (2010/11/18)
A series of osmate (OsO42-) core dendrimers was prepared by an ion-exchange technique through the mixing of K 2OsO4 and a bis(quaternary ammonium bromide) core dendrimer, which consisted of poly(benzyl ether) dendron. By employing an osmate core dendrimer as a homogeneous catalyst, dihydroxylation reactions of olefins proceeded rapidly, and the dendritic osmium catalyst was recovered by reprecipitation and then reused. Furthermore, a dendritic effect on the recyclability of a catalyst was observed. In the case of asymmetric dihydroxylation reactions, the corresponding diol was obtained in a high chemical yield with a fair enantiomeric excess (ee). In this case, not only the dendritic osmium catalyst but also the chiral ligand could be recovered by reprecipitation and reused efficiently up to five times.
Osmium-catalyzed asymmetric dihydroxylation by carbon dioxide-activated hydrogen peroxide and N-methylmorpholine
Balagam, Bharathi,Mitra, Ranjan,Richardson, David E.
, p. 1071 - 1075 (2008/09/18)
An improved process has been developed for the osmium-catalyzed dihydroxylation of olefins via in situ formation of NMO from NMM using CO2 catalysis and H2O2. All olefins examined were selectively cis-dihydroxylated to their corresponding diols in good to excellent yields, and by the use of chiral ligands, high enantiomeric excesses were obtained.
Dihydroxylation of olefins catalyzed by polystyrene-sg-imidazolium resin-supported osmium complex
Jun, Bong-Hyun,Kim, Jong-Ho,Park, Juyoung,Kang, Homan,Lee, Sang-Hyeup,Lee, Yoon-Sik
experimental part, p. 2313 - 2316 (2009/05/07)
Osmium tetroxide was immobilized onto an imidazolium-based polymer, poly(1-methylimidazoliummethyl styrene)-surface grafted-PS (PS-sg-IM) resin. In order to characterize the polymer-imidazolium-supported osmium-complex catalysts, Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray microanalysis (EDX), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) experiments were carried out, and we verified that the formation of the osmium complex occurred only on the surface of the polymer support. This polymer catalysts was used in the dihydroxylation of various olefins, revealed excellent catalytic activity, and could be reused up to three times. Georg Thieme Verlag Stuttgart.
