37975-19-2Relevant academic research and scientific papers
A metal-free strategy for the cross-dehydrogenative coupling of 1,3-dicarbonyl compounds with 2-methoxyethanol
Chang, Yu-Lun,Huang, Sheng-Hua,Kudale, Vishal Suresh,Wang, Jeh-Jeng,Zheng, Sheng
supporting information, p. 1226 - 1230 (2022/02/21)
Here, we report a metal-free approach for the construction of methylene-bridged bis-1,3-dicarbonyl compounds via cross-dehydrogenative coupling of 1,3-dicarbonyl compounds with 2-methoxyethanol. In addition, we have extended this methodology to synthesize tetra-substituted pyridine derivatives using 1,3-dicarbonyl, 2-methoxyethanol and NH4OAc in one step. The key advantages include accepting a wide range of substrates, utilizing O2 as the sole oxidant, and synthesizing biologically active compounds such as 1,4-dihydropyridine and pyrazole. This journal is
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.
Transition-metal-free formal decarboxylative coupling of ?±-oxocarboxylates with ?±-bromoketones under neutral conditions: A simple access to 1,3-diketones
He, Zhen,Qi, Xiaotian,Li, Shiqing,Zhao, Yinsong,Gao, Ge,Lan, Yu,Wu, Yiwei,Lan, Jingbo,You, Jingsong
supporting information, p. 855 - 859 (2015/02/05)
A transition-metal-free formal decarboxylative coupling reaction between ?±-oxocarboxylates and ?±-bromoketones to synthesize 1,3-diketone derivatives is presented. In this reaction, a broad scope of substrates can be employed, and neither a metal-based reagent nor an additional base is required. DFT calculations reveal that this reaction proceeds through a coupling followed by decarboxylation mechanism and the ?±-bromoketone unprecedentedly serves as a nucleophile under neutral conditions. The rate-determining step is an unusual hydrogen-bond-assisted enolate formation by thermolysis.
Asymmetric Mannich synthesis of α-amino esters by anion-binding catalysis
Wasa, Masayuki,Liu, Richard Y.,Roche, Stéphane P.,Jacobsen, Eric N.
supporting information, p. 12872 - 12875 (2016/10/06)
We report a scalable, one-pot Mannich route to enantioenriched α-amino esters by direct reaction of α-chloroglycine ester as a practical imino ester surrogate. The reaction is promoted by a chiral aminothiourea, which is proposed to operate cooperatively
Nucleophilic acylation of α-haloketones with aldehydes: An umpolung strategy for the synthesis of 1,3-diketones
Singh, Santosh,Singh, Pankaj,Rai, Vijai K.,Kapoor, Ritu,Yadav, Lal Dhar S.
experimental part, p. 125 - 128 (2011/02/26)
The first example of N-heterocyclic carbene (NHC)-promoted intermolecular acylation of α-haloketones with aldehydes and α,β-unsaturated aldehydes (enals) is reported. The protocol involves carbonyl umpolung reactivity of aldehydes and enals in which the carbonyl carbon attacks nucleophilically on electrophilic terminal of α-haloketones to afford 1,3-diketones and α,β-unsaturated 1,3-diketones, respectively. Short reaction time, ambient temperature, operational simplicity, and high yields are the salient features of the present procedure.
Clemmensen reduction. XII The synthesis and acidolysis of some diaryl-substituted cyclopropane-1,2-diols. The possible involvement of a cyclopropyl cation
Davis, Brian R.,Hinds, Mark G.
, p. 309 - 319 (2007/10/03)
The generation of a number of 1,2-diarylcyclopropane-1,2-diols is reported. Reaction of these in situ with acid gives, primarily, an α,β-unsaturated ketone in which the aryl substituent attached to the double bond is that which is best able to stabilize a benzylic cation. It is proposed that the reaction proceeds by O-protonation of the cyclopropane- 1,2-diol, followed by loss of water and opening of the resulting cyclopropyl cation and final deprotonation. Such initial O-protonation contrasts with the C-protonation normally observed in the acidolysis of cyclopropanols and other dialkyl- and alkylaryl-cyclopropane-1,2-diols.
Imidazo[2,1-b]thiazole derivatives XII. Synthesis and immunoactivity in vitro on human T lymphocyte of several 3-aroylmethyl and 2-aroyl-3-methyl(aryl)-5,6-dihydroimidazo[2,1-b]thiazoles
Robert,Hassanine,Harraga,Seilles
, p. 261 - 271 (2007/10/02)
To estimate the influence of aryl group position on the immunostimulant properties of imidazo[2,1-b]thiazole derivatives, several compounds were obtained and tested, versus tetramisole hydrochloride, on the mobilisation of CD2 receptor by human T lymphocyte. The synthesis use the action of monobrominated β-diketones on the 2-mercaptoimidazoline. So, 1-aryl-4-bromobutane-1,3-diones lead to 3-aroylmethyl-5,6-dihydroimidazo[2,1-b]thiazoles 4. Same, 1-aryl-2-bromobutane-1,3-diones and 1,3-diaryl-2-bromopentane-1,3-diones give respectively 3-aroyl-2-methyl-5,6-dihydroimidazo[2,1-b]thiazoles 5 and 3-aroyl-2-aryl-5,6-dihydroimidazo[2,1-b]thiazoles 6. Better yields are obtained when the reaction presents two steps. The first one, realized in acetone at room temperature, leads to an intermediate S-substituted 4,5-dihydroimidazole which, in second step, is cyclized in imidazo[2,1-b]thiazole compound via an unisolated carbinolamine. This one explains the univocal formation of 5 derivatives and the feasible blending in case of 6. The immunoactivity of several imidazothiazoles 4, 5 and 6 is lower that them of 6-aryl substituted compounds and particularly that the levamisole which is the reference product in this series.
Synthesis and antimicrobial activity of 1-(4-chlorophenyl)-3-(4-methoxy/3,4-dimethoxyphenyl)propan-1,3-diones and their 2-analogs
Singh, Rajvir,Malik, Om Parkash
, p. 455 - 459 (2007/10/02)
The condensation of substituted acetophenones 1-5 with 4-methoxy- or 3,4-dimethoxy-benzaldehyde (6,7) in ethanolic NaOH gives the corresponding substituted 2-propen-1-ones (8-17) which on bromination yields substituted propan-1-ones (18-27).Refluxing of 1
