1846-29-3Relevant academic research and scientific papers
Structural insights into the desymmetrization of bulky 1,2-dicarbonyls through enzymatic monoreduction
Rabuffetti, Marco,Cannazza, Pietro,Contente, Martina Letizia,Pinto, Andrea,Romano, Diego,Hoyos, Pilar,Alcantara, Andres R.,Eberini, Ivano,Laurenzi, Tommaso,Gourlay, Louise,Di Pisa, Flavio,Molinari, Francesco
supporting information, (2021/01/25)
Benzil reductases are dehydrogenases preferentially active on aromatic 1,2-diketones, but the reasons for this peculiar substrate recognition have not yet been clarified. The benzil reductase (KRED1-Pglu) from the non-conventional yeast Pichia glucozyma showed excellent activity and stereoselectivity in the monoreduction of space-demanding aromatic 1,2-dicarbonyls, making this enzyme attractive as biocatalyst in organic chemistry. Structural insights into the stereoselective monoreduction of 1,2-diketones catalyzed by KRED1-Pglu were investigated starting from its 1.77 ? resolution crystal structure, followed by QM and classical calculations; this study allowed for the identification and characterization of the KRED1-Pglu reactive site. Once identified the recognition elements involved in the stereoselective desymmetrization of bulky 1,2-dicarbonyls mediated by KRED1-Pglu, a mechanism was proposed together with an in silico prediction of substrates reactivity.
Unusual Reactivity of 4-Vinyl Isoxazoles in the Copper-Mediated Synthesis of Pyridines, Employing DMSO as a One-Carbon Surrogate
Kumar, Pravin,Kapur, Manmohan
supporting information, p. 5855 - 5860 (2020/07/30)
An efficient protocol for the synthesis of nicotinate derivatives and tetrasubstituted pyridines through a copper-mediated cleavage of isoxazoles has been developed. The highlight of the work is the observation of an unusual reactivity of 4-vinyl isoxazoles under the reaction conditions. DMSO serves as a one-carbon surrogate generating an active methylene group during the reaction to form two C-C bonds. This protocol provides a facile and an expeditious approach for the assembly of densely substituted N-heterocyclic compounds.
Tf2O-Mediated Intermolecular Coupling of Secondary Amides with Enamines or Ketones: A Versatile and Direct Access to β-Enaminones
Liu, Yong-Peng,Zhu, Cheng-Jie,Yu, Cun-Cun,Wang, Ai-E,Huang, Pei-Qiang
, p. 7169 - 7174 (2019/11/16)
Based on the Tf2O-mediated intermolecular reaction of secondary amides with enamines derived from ketones, a novel approach to β-enaminones has been developed. The reaction is widely functional group tolerant and highly chemoselective. In the presence of 4 ? molecular sieves, the method can be extended to the one-pot condensation of secondary amides with ketones for NH β-enaminones synthesis.
Copper-catalyzed methylation of 1,3-diketones with tert-butyl peroxybenzoate
Zhou, Zhi-Hao,Li, Cheng-Kun,Zhou, Shao-Fang,Shoberu, Adedamola,Zou, Jian-Ping
, p. 2740 - 2746 (2017/04/18)
Copper-catalyzed radical methylation of 1,3-diketones with tert-butyl peroxybenzoate in air is described, providing a general pathway to α-methyl 1,3-diketones in moderate to good yields. This protocol has been scaled up to 50?g, and one of the synthesized products can be used in the synthesis of medicine, Rosuvastatin.
Method for preparing 2-methyl-1,3-dicarbonyl derivative
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Paragraph 0021, (2016/10/08)
The invention discloses a method for preparing a 2-methyl-1,3-dicarbonyl derivative. A 1,3-dicarbonyl derivative serves as an initiator, raw materials are easy to obtain, and a great variety of raw materials are available. The product obtained through the method has high type diversity and can be used directly or used for other further reactions. Besides, only organic peroxides and a catalytic amount of inorganic copper salt are used, so that cost is low. According to the method, a reaction is conducted in air, reaction conditions are mild, pollution is small, reaction time is short, the yield of the target product is high, reaction operation and aftertreatment are easy, and the method is suitable for industrial production.
Oxidative umpolung ?±-alkylation of ketones
Shneider, O. Svetlana,Pisarevsky, Evgeni,Fristrup, Peter,Szpilman, Alex M.
supporting information, p. 282 - 285 (2015/03/05)
We disclose a hypervalent iodine mediated ?±-alkylative umpolung reaction of carbonyl compounds with dialkylzinc as the alkyl source. The reaction is applicable to all common classes of ketones including 1,3-dicarbonyl compounds and regular ketones via their lithium enolates. The ?±-alkylated carbonyl products are formed in up to 93% yield. An ionic mechanism is inferred based on meticulous analysis, NMR studies, trapping and crossover experiments, and computational studies.
Variations in the blaise reaction: Conceptually new synthesis of 3-amino enones and 1,3-diketones
Rao, H. Surya Prakash,Muthanna, Nandurka
supporting information, p. 1525 - 1532 (2015/03/04)
Organic compounds with 3-amino enone or 1,3-diketone functional groups are extremely important, as they can be converted into a plethora of heterocyclic or carbocyclic compounds, or can be used as ligands in metal complexes. We have achieved a new, easy, straightforward and convenient synthesis of 3-amino enones and 1,3-diketones starting from aryl/heteroaryl/alkyl nitriles and 1-aryl/alkyl 2-bromoethanones. The reaction is a variation of the classical Blaise reaction, and it works with zinc and trimethylsilyl chloride as an activator. By running the hydrolysis of the reaction intermediate with HCl (3 N aq.) at 0-30 °C or at 100 °C, it is possible to form either 3-amino enones or 1,3-diketones, respectively. The newly developed method was used for the synthesis of avobenzone, an ingredient of sun-screen lotions. Furthermore, an easy synthesis of (Z)-3-amino-1-[4-(tertbutyl) phenyl]-3-(4-methoxyphenyl)prop-2-en-1-one, with UV/Vis absorption characteristics similar to those of avobenzone, was also achieved.
Hit-to-lead optimization of 2-(1H-pyrazol-1-yl)-thiazole derivatives as a novel class of EP1 receptor antagonists
Atobe, Masakazu,Naganuma, Kenji,Kawanishi, Masashi,Morimoto, Akifumi,Kasahara, Ken-Ichi,Ohashi, Shigeki,Suzuki, Hiroko,Hayashi, Takahiko,Miyoshi, Shiro
, p. 6064 - 6067 (2013/11/06)
We describe a medicinal chemistry approach to generate a series of 2-(1H-pyrazol-1-yl)thiazole compounds that act as selective EP1 receptor antagonists. The obtained results suggest that compound 12 provides the best EP1 receptor ant
Pd-catalyzed carbonylative α-arylation of aryl bromides: Scope and mechanistic studies
Nielsen, Dennis U.,Lescot, Camille,Gogsig, Thomas M.,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information, p. 17926 - 17938 (2014/01/17)
Reaction conditions for the three-component synthesis of aryl 1,3-diketones are reported applying the palladium-catalyzed carbonylative α-arylation of ketones with aryl bromides. The optimal conditions were found by using a catalytic system derived from [Pd(dba)2] (dba=dibenzylideneacetone) as the palladium source and 1,3-bis(diphenylphosphino)propane (DPPP) as the bidentate ligand. These transformations were run in the two-chamber reactor, COware, applying only 1.5 equivalents of carbon monoxide generated from the CO-releasing compound, 9-methylfluorene-9-carbonyl chloride (COgen). The methodology proved adaptable to a wide variety of aryl and heteroaryl bromides leading to a diverse range of aryl 1,3-diketones. A mechanistic investigation of this transformation relying on 31P and 13C NMR spectroscopy was undertaken to determine the possible catalytic pathway. Our results revealed that the combination of [Pd(dba)2] and DPPP was only reactive towards 4-bromoanisole in the presence of the sodium enolate of propiophenone suggesting that a [Pd(dppp)(enolate)] anion was initially generated before the oxidative-addition step. Subsequent CO insertion into an [Pd(Ar)(dppp)(enolate)] species provided the 1,3-diketone. These results indicate that a catalytic cycle, different from the classical carbonylation mechanism proposed by Heck, is operating. To investigate the effect of the dba ligand, the Pd0 precursor, [Pd(η3-1-PhC 3H4)(η5-C5H5)], was examined. In the presence of DPPP, and in contrast to [Pd(dba)2], its oxidative addition with 4-bromoanisole occurred smoothly providing the [PdBr(Ar)(dppp)] complex. After treatment with CO, the acyl complex [Pd(CO)Br(Ar)(dppp)] was generated, however, its treatment with the sodium enolate led exclusively to the acylated enol in high yield. Nevertheless, the carbonylative α-arylation of 4-bromoanisole with either catalytic or stoichiometric [Pd(η3-1-PhC3H4) (η5-C5H5)] over a short reaction time, led to the 1,3-diketone product. Because none of the acylated enol was detected, this implied that a similar mechanistic pathway is operating as that observed for the same transformation with [Pd(dba)2] as the Pd source. CO-operation is the key! The first palladium-catalyzed carbonylative α-arylation of aryl bromides is described. A wide array of different aryl 1,3-diketones can be isolated in good-to-excellent yields using only stoichiometric amounts of CO (see scheme). A mechanistic study is presented that suggests the need for enolate coordination prior to oxidative addition when [Pd(dba)2] is employed as the precatalyst. Copyright
Regioselectivity switch: Gold(I)-catalyzed oxidative rearrangement of propargyl alcohols to 1,3-diketones
Hashmi, A. Stephen K.,Wang, Tao,Shi, Shuai,Rudolph, Matthias
, p. 7761 - 7767 (2012/11/07)
The gold(I)-catalyzed oxidative rearrangement of propargyl alcohols provides an efficient and selective route to 1,3-diketones under mild conditions. Pyridine-N-oxides were used as external oxidants with, different from related substrates, no alkylidenecycloalkanones or oxetan-3-ones formed as side-products.
