102285-85-8Relevant articles and documents
A new halogen-exchange reaction between Sn-F and Li-X: Selective 1,2- and 1,4-reductions of α,β-unsaturated ketones and effects of halogen substituents on the regioselectivity of organotin hydrides
Moriuchi-Kawakami, Takayo,Matsuda, Haruo,Shibata, Ikuya,Miyatake, Masato,Suwa, Toshihiro,Baba, Akio
, p. 465 - 470 (1999)
We have found that halogen-exchange occurs effectively between Sn-F and Li-X (X = I, Br, Cl) in tin hydride reagents. This fact induced a complete change in the regiochemistry in the reductions of α,β-unsaturated ketones 1 with Bu2SnH2-Bu2SnF2 (Reagent A): the use of Reagent A in combination with HMPA performed 1,2-reductions, while the addition of LiI to Reagent A achieved 1,4-reductions. It was demonstrated that the regioselectivity of organotin hydrides greatly depends on the properties of the halogen substituents attached to tin atoms.
Hydrophobic polymer-supported scandium catalyst for carbon-carbon bond-forming reactions in water
Iimura, Shinya,Manabe, Kei,Kobayashi, Shu
, p. 7673 - 7678 (2004)
It has been revealed that a hydrophobic polymer-supported scandium(III) catalyst prepared from sulfonated polystyrene resin is an effective catalyst for carbon-carbon bond-forming reactions such as Mukaiyama aldol reactions in water. According to studies
Iron(III) chloride as a water-compatible lewis acid for diastereoselective aldol reactions in water in the presence of a surfactant
Aoyama, Naohiro,Manabe, Kei,Kobayashi, Shu
, p. 312 - 313 (2004)
Diastereoselective aldol reactions of various aldehydes with silicon enolates in water have been successfully carried out using iron(III) chloride and a surfactant. Contrary to previous understanding, iron(III) chloride has been shown to be a water-compat
The chemistry of trichlorosilyl enolates. 2. Highly-selective asymmetric aldol additions of ketone enolates
Denmark,Wong,Stavenger
, p. 2333 - 2334 (1997)
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Polymer-micelle incarcerated scandium as a polymer-supported catalyst for high-throughput organic synthesis
Takeuchi, Masahiro,Akiyama, Ryo,Kobayashi, Shu
, p. 13096 - 13097 (2005)
A novel immobilization technique for Sc(OTf)3, a polymer-micelle incarcerated (PMI) method, has been developed. PMI Sc(OTf)3 is highly active in several fundamental carbon-carbon bond-forming reactions. The catalyst is recovered quan
A NEW CONVERSION OF SILYL ENOL ETHERS INTO THE CORRESPONDING BORON ENOLATES WITH DIALKYLBORON HALIDES OR DIALKYLBORON TRIFLATES, AND CROSS ALDOL REACTIONS VIA THE BORON ENOLATES
WADA, Makoto
, p. 153 - 156 (1981)
Silyl enol ethers react with dialkylboron halides or dialkylboron triflates to give the corresponding boron enolates quantitatively under mild conditions.Boron enolates thus generated are effectively used to afford cross aldol products with benzaldehyde.
Self-Assembled Single-Walled Metal-Helical Nanotube (M-HN): Creation of Efficient Supramolecular Catalysts for Asymmetric Reaction
Jiang, Jian,Meng, Yan,Zhang, Li,Liu, Minghua
, p. 15629 - 15635 (2016)
Ever since the axial chiral catalysts were developed for asymmetric reactions with excellent chiral discrimination and high efficiencies, the interest in the supramolecular catalyst has also been extensively investigated. Here, with a hint from the typical molecular catalyst, we developed a series of metal-coordinated nanotube (M-helical nanotube, M-HN) catalysts for asymmetric reactions. The M-HN catalyst was fabricated on the basis of the self-assembly of an l-glutamic acid terminated bolaamphiphile, which formed a single-walled nanotube. On one hand, through the coordination of transition metal ions with the carboxylic acid groups on the nanotube surface, a wide variety of single-walled M-HN catalysts could be fabricated, in which the coordination sites could serve as the catalytic sites. On the other hand, using a slight amount of these catalysts, significant reactivity and enantioselectivity were realized for certain asymmetric reactions under mild conditions. Remarkably, Bi(III)-HN could catalyze the asymmetric Mukaiyama aldol reaction with high enantioselectivity (up to 97% ee) in an aqueous system; Cu(II)-HN catalyzed the asymmetric Diels-Alder reaction with up to 91% ee within 60 min. It was suggested that a synergetic effect of the aligned multicatalytic sites and stereochemical selectivity of the M-HN lead to an excellent catalytic performance. Through this work, we proposed a new concept of a single-walled nanotube as catalyst and showed the first example of nanotube catalysts presenting high reactivity and enantioselectivity that rivaled a chiral molecular catalyst.
The Phenyldimethylsilyl Group as a Masked Form of the Hydroxy Group
Fleming, Ian,Henning, Rolf,Plaut, Howard
, p. 29 - 31 (1984)
The phenyldimethylsilyl group can be converted in two steps, protodesilylation and peracid-mediated rearrangement, into a hydroxy group with retention of configuration: β-phenyldimethylsilyl carbonyl compounds are thus revealed to be masked aldol products.
Efficient synthesis of β-hydroxy ketones from allylic alcohols by catalytic formation of ruthenium enolates
Bartoszewicz, Agnieszka,Livendahl, Madeleine,Martin-Matute, Belen
, p. 10547 - 10550 (2008)
A study was conducted to demonstrate the synthesis of β-hydroxy ketones from allylic alcohols by catalytic formation of ruthenium enolates. KOtBu was added to a mixture of complex Ru, containing a cyclopentadienyl ligand bearing five phenyl groups. It was demonstrated that ruthenium chloride reacts with KOtBu, forming a ruthenium tert-butoxide complex. It was also demonstrated that the reaction of the tert-butoxide complex with allylic alcohol produced a new alkoxide, as detected by H NMR spectroscopy.
Iron-Modified Mesoporous Silica as an Efficient Solid Lewis Acid Catalyst for the Mukaiyama Aldol Reaction
Xu, Wan,Ollevier, Thierry,Kleitz, Freddy
, p. 1932 - 1944 (2018)
Fe-MCM-41 and Fe-SBA-15, two different iron-containing mesoporous silicas, were successfully synthesized by a straightforward and versatile method using iron acetylacetonate as a metal precursor. pH adjustment with ammonia during the synthesis was found t
Highly efficient redox isomerization of allylic alcohols at ambient temperature catalyzed by novel ruthenium-cyclopentadienyl complexes - New insight into the mechanism
Martin-Matute, Belen,Bogar, Krisztian,Edin, Michaela,Kaynak, F. Betuel,Baeckvall, Jan-E.
, p. 5832 - 5842 (2005)
A range of ruthenium cyclopentadienyl (Cp) complexes have been prepared and used for isomerization of allylic alcohols to the corresponding saturated carbonyl compounds. Complexes bearing CO ligands show higher activity than those with PPh3 ligands. The isomerization rate is highly affected by the substituents on the Cp ring. Tetra(phenyl)methyl-substituted catalysts rapidly isomerize allylic alcohols under very mild reaction conditions (ambient temperature) with short reaction times. Substituted allylic alcohols have been isomerized by employing Ru-Cp complexes. A study of the isomerization catalyzed by [Ru-(Ph5Cp)(CO)2H] (14) indicates that the isomerization catalyzed by ruthenium hydrides partly follows a different mechanism than that of ruthenium halides activated by KOtBu. Furthermore, the lack of ketone exchange when the isomerization was performed in the presence of an unsaturated ketone (1 equiv), different from that obtained by dehydrogenation of the starting allylic alcohol, supports a mechanism in which the isomerization takes place within the coordination sphere of the ruthenium catalyst.
Synthesis of a Bolm's 2,2′-Bipyridine Ligand Analogue and Its Applications
Bedná?ová, Eva,Dra?ínsky, Martin,Malatinec, ?tefan,Císa?ová, Ivana,Lamaty, Frédéric,Kotora, Martin
supporting information, p. 2869 - 2878 (2018/08/17)
A new method of synthesis of an analogue of Bolm's 2,2′-bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1-halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2-bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)-2 was then tested as a chiral ligand in metal-catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama-aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents. (Figure presented.).
