13988-65-3Relevant academic research and scientific papers
Synthesis, x-ray crystallographic and 1H NMR spectroscopic structural studies on cobalt(II) complexes of homoscorpionate, heteroscorpionates and chiral tris(pyrazolyl)borates obtained from 5(3)-isopropyl-3(5)-phenylpyrazole and 3,5-dimethylpyrazole
Ruman, Tomasz,Ciunik, Zbigniew,Wolowiec, Stanislaw
, p. 2475 - 2485 (2003)
Condensation of 5(3)-isopropyl-3(5)-phenylpyrazole with sodium borohydride led to a mixture of tris (pyrazolyl)borate ligands (Tpx) - the homoscorpionate hydrotris(5-isopropyl-3-phenylpyrazolyl)borate and the heteroscorpionates hydro(3-isopropyl-5-phenylpyrazolyl)bis(5-isopropyl-3-phenylpyrazolyl)borate and hydrobis(3-isopropyl-5-phenylpyrazolyl)(5-isopropyl-3-phenylpyrazolyl)borate - that were converted into TpxCo(NCS) complexes. The molecular structures of pentacoordinate[hydrotris(5-isopropyl-3-phenylpyrazolyl)- borato](tetrahydrofuran)(thiocyanato)cobalt(II) (1-THF) and [hydrobis(3-isopropyl-5-phenylpyrazolyl) (5-isopropyl-3-phenylpyrazolyl)borato] (tetrahydrofuran)(thiocyanato)-cobalt(II) (3-THF) were elucidated crystallographically. Hydro(3,5-dimethylpyrazolyl)bis(5-isopropyl-3-phenylpyrazolyl)borate was also obtained by condensation of 2.1 equiv. of 5(3)-isopropyl-3(5)-phenylpyrazole and 0.9 equiv. of 3,5-dimethylpyrazole with sodium borohydride, and it was converted into [hydro(3,5-dimethylpyrazolyl)bis (5-isopropyl-3-phenylpyrazolyl)borato](thiocyanato)cobalt(II) (4), which was characterized by X-ray crystallography. The latter was converted thermally under mild conditions (358 K in toluene) into [hydro(3,5-dimethylpyrazolyl)(3-isopropyl-5-phenyl-pyrazolyl) (5-isopropyl-3-phenylpyrazolyl)borato](thio-cyanato)cobalt(II) (9) in 45% yield, as was concluded from the 1H NMR spectrum of the post-reaction mixture. The dimer of 9 was obtained as single crystals from toluene/hexane and its structure was determined crystallographically. Two chiral Tpx ligands of opposite boron-centered configurations are coordinated to cobalt(II) ions in a κ3 fashion. The pentacoordinate metal ions are bridged head-to-tail by the thiocyanate anions. This chiral Tpx ligand is the first example of a borate with fixed boron-centered chirality. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
I2-Promoted [3+2] Cyclization of 1,3-Diketones with Potassium Thiocyanate: a Route to Thiazol-2(3H)-One Derivatives
An, Zhenyu,Liu, Yafeng,Yan, Rulong,Zhao, Pengbo
supporting information, p. 3240 - 3244 (2021/06/16)
An I2-promoted strategy has been developed for the synthesis of thiazol-2(3H)-one derivatives from 1,3-diketones with potassium thiocyanate. This [3+2] cyclization reaction involves C?S and C?N bond formation and exhibits good functional group tolerance. A series of thiazol-2(3H)-one derivatives are obtained in moderate to good yields. (Figure presented.).
Method for synthesizing 1, 3-dicarbonyl compound based on terminal alkyne and acyl halide by one-pot process
-
Paragraph 0069-0074; 0126-0128, (2020/07/21)
The invention belongs to the technical field of catalytic synthesis, and discloses a method for synthesizing a 1, 3-dicarbonyl compound by a one-pot process, and the method comprises the following steps: by using simple palladium and copper salts as catalysts, reacting terminal alkyne with acyl halide at 0-80 DEG C for 0.5-12 hours under the action of trifluoromethanesulfonic acid to obtain the 1,3-dicarbonyl compound, wherein the molar ratio of the terminal alkyne to the acyl halide to the palladium salt to the copper salt to the trifluoromethanesulfonic acid is 1 to (1 to 2) to (0.00001 to0.10) to (0.00001 to 0.10) to (0.00004 to 0.40); the catalysts used in the method are common the commercialized palladium salt and copper salt, reagents used in the reaction are commercialized reagents, in addition, the raw materials are cheap and easy to obtain, functional group tolerance is good, reaction conditions are mild, operation is easy and convenient, and atom economy is high.
Synthesis of 1,3-Diketones and β-Keto Thioesters via Soft Enolization
Aderibigbe, Sabrina O.,Coltart, Don M.
, p. 9770 - 9777 (2019/08/27)
Ketones and thioesters undergo soft enolization and acylation using crude acid chlorides on treatment with MgBr2·OEt2 and i-Pr2NEt to give 1,3-diketones and β-keto thioesters, respectively. The use of crude acid chlorides adds efficiency and cost reduction by avoiding the need to purify and/or purchase them. The process is conducted in a direct fashion that does not require prior enolate formation, further enhancing its efficiency and making it very easy to carry out. The method is suitable for large scale applications. ?
Highly enantioselective Michael addition of 2-fluoro-1,3-diketones to nitroalkenes
Kwiatkowski, Jacek,Lu, Yixin
supporting information, p. 320 - 324 (2015/02/19)
Highly enantioselective Michael addition of 2-fluoro-1,3 diketones to nitroalkenes was developed, and the desired adducts were obtained in good chemical yields with moderate to good diastereoselectivties and excellent enantioselectivities. Subsequent stereoselective reduction of the carbonyl groups led to the preparation of a functionalized fluoroisostere of glycerol that contains four continuous stereogenic centers.
1,4-Addition of Bis(iodozincio)methane to α,β-Unsaturated ketones: Chemical and theoretical/computational studies
Sada, Mutsumi,Furayama, Taniyuki,Komagawa, Shinsuke,Uchiyama, Masanobu,Matsubara, Seijiro
experimental part, p. 10474 - 10481 (2010/10/21)
1,4-Addition of bis(iodozincio)methane to simple α,β-unsaturated ketones does not proceed well; the reaction is slightly endothermic according to DFT calculations. In the presence of chlorotrimethylsilane, the reaction proceeded efficiently to afford a silyl enol ether of β-zinciomethyl ketone. The CZn bond of the silyl enol ether could be used in a cross-coupling reaction to form another C-C bond in a one-pot reaction. In contrast, 1,4-addition of the dizinc reagent to enones carrying an acyloxy group proceeded very efficiently without any additive. In this case, the product was a 1,3-diketone, which was generated in a novel tandem reaction. A theoretical/computational study indicates that the whole reaction pathway is exothermic, and that two zinc atoms of bis(iodozincio)methane accelerate each step cooperatively as effective Lewis acids.
The structure of pyrazoles in the solid state: A combined CPMAS, NMR, and crystallographic study
Claramunt, Rosa M.,Cornago, Pilar,Torres, Veronica,Pinilla, Elena,Torres, M. Rosario,Samat, Andre,Lokshin, Vladimir,Vales, Magali,Elguero, Jose
, p. 6881 - 6891 (2007/10/03)
The structures of six N-unsubstituted pyrazoles, three already known and three newly synthesized, have been studied by a combination of X-ray crystallography, multinuclear NMR (solution and solid state), and density functional theory (DFT) calculations. I
Enantioselective borohydride reduction catalyzed by optically active cobalt complexes
Yamada, Tohru,Nagata, Takushi,Sugi, Kiyoaki D.,Yorozu, Kiyotaka,Ikeno, Taketo,Ohtsuka, Yuhki,Miyazaki, Daichi,Mukaiyama, Teruaki
, p. 4485 - 4509 (2007/10/03)
The highly enantioselective borohydride reduction of aromatic ketones or imines to the corresponding alcohols was developed in the presence of a catalytic amount of an optically active cobalt(II) complex catalyst. This enantioselective reduction is carried out using a precisely premodified borohydride with alcohols such as tetrahydrofurfuryl alcohol, ethanol and methanol. High optical yields are obtained by choosing the appropriate alcohol as modifiers and a suitable β-ketoiminato ligand of the catalyst. The enantioselective borohydride reduction has been successfully applied to the preparation of optically active 1,3-diols, the stereoselective reduction of diacylferrocenes, and dynamic and/or kinetic resolution of 1,3-dicarbonyl compounds.
Revisiting [3 + 3] route to 1,3-cyclohexanedione frameworks: Hidden aspect of thermodynamically controlled enolates
Ishikawa, Teruhiko,Kadoya, Ryuichiro,Arai, Masaki,Takahashi, Haruka,Kaisi, Yumi,Mizuta, Tomohiro,Yoshikai, Kazusa,Saito, Seiki
, p. 8000 - 8009 (2007/10/03)
We have revisited the traditional consecutive Michael-Claisen [3 + 3] process (MC-[3+3]) promising the synthesis of a cyclohexane-1,3-dione derivatives from nonactivated simple ketones and enoates and evaluated its potential in modern organic synthesis. Twenty to thirty examples were demonstrated to be effective. The reactions exhibited remarkable regioselectivity with the Michael addition proceeding through nucleophilic attack by the more hindered site of the ketones without exception. The subsequent Claisen condensation resulted in the formation of carbon-carbon bonds between less hindered site of the ketones and acyl carbon of the enoates. The MC-[3+3] process described is useful for the synthesis of Taxol A-ring synthons in multigram quantities and for the synthesis of other six-membered carbocyclic compounds. A number of control experiments have been conducted to provide strong support for the mechanism of this MC-[3+3].
