81189-45-9Relevant academic research and scientific papers
Enhanced metal loading in SBA-15-type catalysts facilitated by salt addition: Synthesis, characterization and catalytic epoxide alcoholysis activity of molybdenum incorporated porous silica
Budhi, Sridhar,Peeraphatdit, Chorthip,Pylypenko, Svitlana,Nguyen, Vy H.T.,Smith, Emily A.,Trewyn, Brian G.
, p. 469 - 476 (2014/03/21)
We report a novel method to increase the metal loading in SBA-15 silica matrix via direct synthesis. It was demonstrated through the synthesis and characterization of a series of molybdenum containing SBA-15 mesoporous silica catalysts prepared with and without diammonium hydrogen phosphate (DHP) as an additive. Catalysts prepared with DHP show a 2-3 times increase in incorporation of molybdenum in the silica matrix and pore size enlargement. The synthesized catalysts were characterized using nitrogen sorption, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES). The catalytic activity of catalysts prepared with DHP for alcoholysis of epoxides was superior than the catalyst prepared without DHP. Alcoholysis of epoxides was demonstrated for a range of alcohols and epoxides under ambient conditions in as little as 30 min with high selectivity.
Monoallylation of 1,2-diols by Pd/Sn bimetallic catalysis
Kuriyama, Masami,Takeichi, Tsubasa,Ito, Masaaki,Yamasaki, Noritsugu,Yamamura, Ryota,Demizu, Yosuke,Onomura, Osamu
supporting information; experimental part, p. 2477 - 2480 (2012/04/04)
Efficient and mild: The selective monoallylation of 1,2-diols was successfully developed with Pd/Sn bimetallic catalysis in good to excellent yields. This process was carried out with high substrate tolerance under mild conditions (see scheme). The catalyst system achieved the quite high chemoselectivity even in the presence of a 1:1 mixture of the 1,2-diol and mono-ol. Copyright
Alcoholysis of Epoxides Catalyzed by Tetracyanoethylene and Dicyanoketene Acetals
Masaki, Yukio,Miura, Tsuyoshi,Ochiai, Masahito
, p. 195 - 205 (2007/10/03)
A typical π-acid tetracyanoethylene and capto-dative olefin dicyanoketene acetals were found to catalyze stereospecific alcoholysis of epoxides at the ambient temperature to 50°C in good yields. Mildness and significant chemoselectivity of the catalysts were demonstrated by intactness of tetrahydropyranyl ether and ethylene acetal groups. A novel regioselectivity associated with anchimeric assistance of the ethereal group on the side chain was observed in the ring opening reaction of the 1,2-disubstituted epoxides.
Catalytic activities of dicyanoketene acetals in alcoholysis of epoxides
Miura,Masaki
, p. 523 - 525 (2007/10/02)
The catalytic activity of various types of capto-dative ethylenes has been investigated on alcoholysis of epoxides, and dicyanoketene dimethyl acetal (DCKDMA) and dicyanoketene ethylene acetal (DCKEA) are found to be efficient and mild catalysts.
Intramolecular Free Radical Cyclisations onto Enol Ethers. A General Synthesis of α-Alkyl-β-oxy- and α-Methylene-β-oxy-γ-butyrolactones
Begley, Michael J.,Landlow, Mark,Pattenden, Gerald
, p. 1095 - 1106 (2007/10/02)
Radical cyclisation of the enol ether bromoacetals (26), (28a-c), (29), and (37) in the presence of tributylstannane, produces precursors to the β-oxy-γ-butyrolactones (33), (34a-c), (35), and the α-methylene-β-oxy-γ-butyrolactone (39) in high overall yields.By contrast, treatment of (26) and (28a-b) with the cobalt(I) reagent derived from bis(dimethylglyoximato)(pyridine)cobalt(III) chloride (40), followed by oxidation of the intermediates (43) leads to the corresponding unsaturated β-oxy-γ-butyrolactones (42).
INTRAMOLECULAR FREE RADICAL CYCLISATIONS ONTO VINYL ETHERS. A METHOD FOR THE SYNTHESIS OF β-OXY-γ-BUTYROLACTONES
Ladlow, Mark,Pattenden, Gerald
, p. 4317 - 4320 (2007/10/02)
Radical cyclisation of the vinyl ether bromides (2) and (7) in the presence of tri-n-butylstannane produces precursors to the β-oxy-γ-butyrolactones (6) and (9) in high yields (>80percent).By contrast, treatment of (2) and (7) with bis-(dimethylglyoximato)(pyridine)cobalt(I) chloride followed by oxidation of the intermediates (5) and (11) led to the corresponding unsaturated β-oxy-γ-butyrolactones (4) and (12) respectively.
The Reaction of Bis(dimethylglyoximato)(pyridine)cobalt(I), Cobaloxime(I), with 2-(Allyloxy)ethyl Halides and the Photolysis of the Resulting Organo-cobaloximes
Okabe, Masami,Tada, Masaru
, p. 1498 - 1503 (2007/10/02)
The reactions of 2-(allyloxy)ethyl halides with cobaloxime(I) gave (tetrahydro-3-furanyl)methylcobaloximes via an electron transfer from cobaloxime(I) to the halides to give radical anions.The rupture of a halide ion to give an organic radical and the ring closure to give a (tetrahydro-3-furanyl)methyl radical are followed by the radical coupling between the organic radical and the cobaloxime(II).The structures of the organocobaloximes were determined by the analyses of the photolysis products under aerobic or anaerobic conditions.
