- Photocyclization to cis-Hexahydrocarbazol-4-ones: Substrate Modification, Mechanism, and Scope
-
Upon irradiation at = 366 nm, tertiary N-alkoxycarbonyl-N-aryl-β-enaminones furnished exclusively the trans-hexahydrocarbazol-4-ones by a conrotatory [6π] photocyclization but epimerized on silica to cis-hexahydrocarbazol-4-ones (14 examples, 44-98% yield). The acceptor substitution on the nitrogen atom enhanced the stability of the cyclized products compared to N-alkyl-N-aryl-β-enaminones reported previously. The mechanism of the [6π] photocyclization was investigated by quenching experiments, deuterium-labeling experiments, and DFT calculations, suggesting a triplet pathway for the conrotatory ring closure followed by a suprafacial [1,4] hydrogen migration.
- Modha, Sachin G.,P?thig, Alexander,Dreuw, Andreas,Bach, Thorsten
-
p. 1139 - 1153
(2019/01/30)
-
- A novel and reusable magnetic nanocatalyst developed based on graphene oxide incorporated strontium nanoparticles for the facial synthesis of β-enamino ketones under solvent-free conditions
-
A novel magnetic SrFeGO nanocatalyst (NC) was synthesized through a simple sol–gel technique by introducing strontium and iron oxide nanoparticles onto graphene. The synthesized NC was characterized using FT-IR and FE-SEM. Subsequently, the catalytic activity of SrFeGO was tested in a reaction between β-dicarbonyl compounds and aniline derivatives to gain β-enamino ketone derivatives under solvent-free conditions. It was found that SrFeGO NC is a potential catalyst for the synthesis of β-enamino ketones. The β-enamino ketone produced by such reactions could be isolated in high purity without the need for chromatographic purifications. The newly prepared magnetic graphene oxide nanocomposite could be recovered and reused for numerous times with no significant decrease in efficiency. Moreover, the protocol has the advantages of excellent yielding (up to 98%) in short a reaction time, benefitting an easy workup procedure and being environmentally friendly.
- Mousavi, Seyyed Rasul,Sereshti, Hassan,Rashidi Nodeh, Hamid,Foroumadi, Alireza
-
-
- Cyclic enaminone as new chemotype for selective cyclooxygenase-2 inhibitory, anti-inflammatory, and analgesic activities
-
The cyclic enaminone moiety has been identified as a new scaffold for selective inhibition of cyclooxygenase-2 with anti-inflammatory and analgesic activities. The designed cyclic enaminones have been synthesized conveniently through the development of a new catalyst-free methodology and evaluated for cyclooxygenase (COX-1 and COX-2) inhibitory activities. Three compounds 7d, 8, and 9 predominantly inhibited COX-2 with selectivity index of 74.09, 19.45 and 108.68, respectively, and were assessed for in vivo anti-inflammatory activity in carrageenan induced rat paw edema assay. The anti-inflammatory activity of 7d was comparable to that of celecoxib at a dose of 12.5 mg/kg. However, the compounds 8 and 9 were more/equally effective as anti-inflammatory agent compared to celecoxib at the doses of 12.5 mg/kg and 25 mg/kg and also exhibited anti-inflammatory activity comparable to that of diclofenac. The therapeutic potential of the most active compound 9 was further assessed by performing in vivo thermal and mechanical hyperalgesia tests using various models that revealed its analgesic activity. The in vivo non-ulcerogenicity of 9 revealed the gastrointestinal safety as compared to the non-selective COX inhibitor indomethacin. The in vitro antioxidant activity and in vivo experiments on heart rate and blood pressure provided the cardiovascular safety profile of 9. The molecular docking studies rationalize the COX-2 selectivity of the newly found anti-inflammatory compounds 7d, 8, and 9.
- Kumar, Raj,Saha, Nirjhar,Purohit, Priyank,Garg, Sanjeev K.,Seth, Kapileswar,Meena, Vachan S.,Dubey, Sachin,Dave, Khyati,Goyal, Rohit,Sharma, Shyam S.,Banerjee, Uttam C.,Chakraborti, Asit K.
-
supporting information
(2019/08/26)
-
- Fe-Catalyzed enaminone synthesis from ketones and amines
-
We have developed an iron-catalyzed direct olefination for enaminone synthesis, with saturated ketones as a source of olefins. This direct ketone β-functionalization reaction has readily available starting materials and a wide range of substrates and requires mild reaction conditions.
- Wu, Wenfeng,Wang, Zhuxian,Shen, Qun,Liu, Qiang,Chen, Huoji
-
supporting information
p. 6753 - 6756
(2019/07/22)
-
- Intermolecular Multiple Dehydrogenative Cross-Couplings of Ketones with Boronic Acids and Amines via Copper Catalysis
-
An efficient and versatile oxidative coupling reaction was developed for the synthesis of valuable β-functionalized unsaturated ketones and meta-substituted phenols. In the case of intramolecular reactions, achieving rapid molecular complexity through multiple dehydrogenative couplings is already a well-established strategy. Herein, we report an intermolecular multiple dehydrogenative coupling between ketones and nucleophilic amines or boronic acids using inexpensive copper(I) oxide as a catalyst. This method provides a facile access to highly desirable chemical products such as α,β-unsaturated ketones, enaminones, and synthetically relevant meta-substituted phenols. (Figure presented.).
- Wang, Tianzhang,Chen, Guowei,Lu, Yu-Jing,Chen, Qian,Huo, Yanping,Li, Xianwei
-
supporting information
p. 3886 - 3892
(2019/07/19)
-
- Nano-SiO2 catalyzed synthesis of β-enaminones under solvent free conditions
-
Nano-SiO2 efficiently catalyzed the synthesis of β-enaminones using direct condensation of various (cyclic and acyclic) β-diketones with aromatic and aliphatic amines under solvent-free conditions. This eco-friendly catalyst can be recovered and reused without significant loss of activity. This methodology provides a simple synthetic route to enaminones in excellent yields at room temperature. Graphical abstract: [Figure not available: see fulltext.]
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Sarkati, Malihe Norouzi,Zare, Mahboobe
-
p. 1591 - 1596
(2016/08/16)
-
- Tailoring of spectral response and intramolecular charge transfer in β-enaminones through band gap tuning: Synthesis, spectroscopy and quantum chemical studies
-
In this paper, we investigate the synthetic tailoring of the spectral response and intramolecular charge transfer (ICT) of β-enaminones through bandgap modulation. Two donor/acceptor substituted β-enaminones, namely, 3-(4-methoxyphenylamino)-2-cyclohexen-1-one (OACO) and 3-(4-nitrophenylamino)-2-cyclohexen-1-one (NACO) have been synthesized along with their unsubstituted counterpart, 3-(phenylamino)-2-cyclohexen-1-one (PACO). Steady state as well as time resolved spectroscopic techniques with picosecond resolution are used to record their spectral responses. Substitution of the donor group (-OCH3) mildly enhances the charge transfer from the phenyl ring to the enaminone moiety, while substitution of the acceptor group (-NO2) jeopardizes the charge transfer through mutual electron withdrawing effects of PNA and enaminone moieties. Combined experimental and quantum chemical investigations reveal that the ground state photophysics of OACO and NACO in water are controlled by both microscopic and macroscopic solvation with dominant contribution from the former. Time dependent density functional theory (TDDFT) calculations predict that the HOMO to [LUMO+1] transition gives rise to the absorption spectra of OACO in water, while the absorption by the enaminone moiety of NACO arises as a result of a HOMO to LUMO transition. A crossing between the first (S1) and the second excited (S2) states takes place in the microclusters of PACO, OACO and NACO with water. The intersystem crossing (ISC) has been found to be the major reason for low quantum yields in these molecules. The band gap modulation through waxing and waning of the conjugation strength is expected to throw light on many ICT-driven processes and provides means of tuning the properties depending on it.
- Misra, Ramprasad,Chakraborty, Pushkin,Roy, Subhas C.,Maity,Bhattacharyya
-
p. 36811 - 36822
(2016/05/24)
-
- Synthesis, crystal structure and effect of indeno[1,2-b]indole derivatives on prostate cancer in vitro. Potential effect against MMP-9
-
A highly regiospecific synthesis of a series of indenoindoles is reported, together with X-ray studies and their activity against human prostate cancer cells PC-3 and LNCaP in vitro. The most effective compound 7,7-dimethyl-5-[(3,4-dichlorophenyl)]-(4bRS,9bRS)-dihydroxy-4b,5,6,7,8,9bhexahydro-indeno[1,2-b]indole-9,10-dione 7q reduced the viability in both cell lines in a time and dose-dependent manner. Inhibitory effects were also observed on the adhesion, migration, and invasion of the prostate cancer cells as well as on clonogenic possibly by inhibition of MMP-9 activity. Molecular docking of 7q and 6k into MMP-9 human active site was also performed to determine the probable binding mode.
- Lobo, Gricela,Monasterios, Melina,Rodrigues, Juan,Gamboa, Neira,Capparelli, Mario V.,Martínez-Cuevas, Javier,Lein, Michael,Jung, Klaus,Abramjuk, Claudia,Charris, Jaime
-
p. 281 - 295
(2015/04/27)
-
- FeCl3-Catalyzed Combinatorial Synthesis of Functionalized Spiro[Indolo-3,10′-indeno [1,2- b ]quinolin]-trione Derivatives
-
An efficient, inexpensive, environmentally friendly and high yield one-pot route to new spiro[indolo-3,10′-indeno [1,2-b]quinolin]-trione derivatives has been developed, involving three-component reaction of enaminones, N-substituted isatins and Indane-1,3-dione catalyzed by FeCl3. The approach to this spiro-heterocycle is noteworthy because it results in the formation of three new σ (two C-C and one C-N) bonds in a single operation, leading to the construction of novel spiro skeleton. This method works on a large scale in excellent yields.
- Mondal, Animesh,Mukhopadhyay, Chhanda
-
supporting information
p. 404 - 408
(2016/01/15)
-
- Palladium-catalyzed synthesis of natural and unnatural 2-, 5-, and 7-oxygenated carbazole alkaloids from N-arylcyclohexane enaminones
-
A palladium-catalyzed synthesis of the carbazole framework is described, including the preparation of 2-, 5-, and 7-oxygenated natural and unnatural carbazole alkaloids. A series of N-arylcyclohexane enaminones, generated by condensation of cyclohexane-1,3-dione with diverse anilines, were aromatized by a Pd(0)-catalyzed thermal treatment to afford the corresponding diarylamines. The latter were submitted to a Pd(II)-catalyzed cyclization and methylation processes to provide the desired carbazoles, including clausine V. Following an inverse strategy, a new and short total synthesis of glycoborine is also reported.
- Bautista, Rafael,Montoya, Pablo A.,Rebollar, Araceli,Burgueno, Eleuterio,Tamariz, Joaquin
-
p. 10334 - 10351
(2013/10/22)
-
- IMINO COMPOUNDS AS PROTECTING AGENTS AGAINST ULTRAVIOLET RADIATIONS
-
The present invention relates to compounds having the general Formula I: which absorb UV radiations and protect biological materials as well as non-biological materials from damaging exposure to UV radiations. The present invention also relates to formulations and compositions comprising such compounds for use in absorbing UV radiations and in protecting biological materials as well as non-biological materials against UV radiations.
- -
-
Page/Page column 43-44
(2014/01/08)
-
- Silica supported Fe(HSO4)3 as an efficient, heterogeneous and recyclable catalyst for synthesis of β-enaminones and β-enamino esters
-
A series of β-substituted enaminones were prepared through the one-pot reaction of β-dicarbonyl compounds with various amines in the presence of silica ferric hydrogensulfate under solvent free conditions at room temperature. The reactions proceed smoothl
- Eshghi, Hossein,Seyedi, Seyed Mohammad,Safaei, Elham,Vakili, Mohammad,Farhadipour, Abolghasem,Bayat-Mokhtari, Mohtaram
-
p. 430 - 436
(2012/10/30)
-
- Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation
-
A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd2(dba)3-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.
- Yun, Xi-Liu,Bi, Wen-Ying,Huang, Jian-Hui,Liu, Yu,Zhang-Negrerie, Daisy,Du, Yun-Fei,Zhao, Kang
-
supporting information; experimental part
p. 5076 - 5080
(2012/09/25)
-
- Mild and efficient method for synthesis of eaminones using ytterbium triflate as catalyst
-
A mild and efficient procedure for synthesis of-enaminones by the condensation of-dicarbonyl compounds and amines using ytterbium triflate [Yb(OTf)3] as catalyst is described. The catalyst can be easily recovered and reused without loss of activity. Taylor & Francis Group, LLC.
- Chen, Rener,Li, Ping,Li, Jianjun,Su, Weike
-
experimental part
p. 2506 - 2512
(2010/09/14)
-
- Concurrent α-iodination and N-arylation of cyclic β-enaminones
-
A variety of N-substituted 3-aminocyclohex-2-enones were converted into the corresponding N-arylated α-iodo enaminones in high yields via concurrent N-iodination and N-arylation mediated by ArI(OAc)2. A mechanism is postulated to account for the reaction differences between the cyclic and the acyclic -enaminones, which undergo predominant β-acetoxylation under the same reaction conditions.
- Chen, Yan,Ju, Tong,Wang, Junwei,Yu, Wenquan,Du, Yunfei,Zhao, Kang
-
supporting information; experimental part
p. 231 - 234
(2010/06/15)
-
- An improved method for the synthesis of carbazolones by palladium/copper-catalyzed intramolecular annulation of n -arylenaminones
-
An improved method for the synthesis of carbazolones via the condensation of arylamines with 1,3-cyclodiketones followed by intramolecular oxidative cyclization catalyzed by palladium acetate and copper acetate in ethanol under an oxygen atmosphere was established. The improved method has the advantage of easily available starting materials and affords good yields.
- Weng, Bojie,Liu, Rui,Li, Jing-Hua
-
experimental part
p. 2926 - 2930
(2010/10/18)
-
- Ionic liquid promoted synthesis of β-enamino ketones at room temperature
-
β-Enamino ketones have been synthesised in excellent yield at room temperature in the absence of any added catalyst by the reaction of aromatic or aliphatic amines with 1,3-dicarbonyl compounds in ionic liquid. The ionic liquid is recycled and reused several times. Georg Thieme Verlag Stuttgart.
- Bhosale, Rajesh S.,Suryawanshi, Padmakar A.,Ingle, Sachin A.,Lokhande, Mahendra N.,More, Sandeep P.,Mane, Sandeep B.,Bhosale, Sidthanath V.,Pawar, Rajendra P.
-
p. 933 - 935
(2007/10/03)
-
- Iminium Salts in Solid-State Syntheses Giving 100% Yield
-
Numerous reaction types in the field of iminium salts are performed in the gas-solid and solid-solid techniques in order to reach 100% yield. The stoichiometric runs are waste-free and do not require costly workup. Frequently, iminium salts were avoided, as acid catalysis was dispensable. Thioureas and α-halogenated ketones give a variety of 2-aminothiazoles via thiuronium salts in quantitative yield. A new intramolecular solid-state thermal condensation is reported. Enaminoketones are synthesized quantitatively from anilines and 1,3-diketones without catalysis and those can be used for quantitative solid-state 4-cascade reactions. Solid paraformaldehyde is used to produce methylene imines and internally trapped methylene iminium salts. Benzoylhydrazones are produced again without catalysis in the solid state. Vacuum and ball-mill techniques are particularly useful in the production of highly sensitive iminium salts. Hexahydro-1,3,5-triazines cyclorevert upon exposure to HCl gas to give solid arylmethylene iminium chlorides as new versatile reagents. These are used in arylaminomethylations of β-naphthol and of themselves to give Troeger's bases in 3-cascades. More direct are 4-cascade Troeger's base syntheses by dissolving hexahydro-1,3,5-triaryltriazines in trifluoroacetic acid. Alkylations of imines with trimethyloxonium tetrafluoroborate and triphenylmethyl cation give highly sensitive quaternary iminium salts in the ball-mill. The products are characterized by spectroscopic techniques and density functional theory (DFT) calculations at the B3LYP 6-31G* level. Molecular movements in the crystal and surface passivation are investigated with atomic force microscopy (AFM) techniques.
- Kaupp, Gerd,Schmeyers, Jens,Boy, Juergen
-
p. 269 - 280
(2007/10/03)
-
- Intermolecular N - H...O Hydrogen Bonding Assisted by Resonance. II. Self Assembly of Hydrogen-Bonded Secondary Enaminones in Supramolecular Catemers
-
The crystal structures of 15 compounds containing the 2-en-3-amino-1-one heterodienic system and forming intermolecular N - H...O hydrogen bonds assisted by resonance (RAHB) are reported: (1) 3-phenylamino-2-cyclohexen-1-one; (2) 3-(4-methoxyphenylamino)-
- Bertolasi, Valerio,Gilli, Paola,Ferretti, Valeria,Gilli, Gastone
-
-
- NMR of enaminones part 3 ? - 1H, 13C and 17O NMR spectroscopic studies of acyclic and cyclic N-aryl enaminones: Substituent effects and intramolecular hydrogen bonding
-
17O, 13C and 1H NMR spectra for para-and meta-substituted 4-arylaminopent-3-en-2-ones (acyclic enaminones, 1 and 2) and 3-arylaminocyclohex-2-en-1-ones (cyclic enaminones, 3 and 4) are reported. The 17O, 13C and 1H shift values of these enaminones correlate well with σm0 and σp- constants in the correlations for meta and para derivatives, and with pKa values of the corresponding anilines. Dual substituent parameters analyses were also performed. Correlations of 17O and 13C chemical shifts of the carbonyl groups with those of the corresponding N-acylanilines indicate that the enaminone moiety as a whole has electronic properties similar to those of the RCONH group. The 17O shift values of the carbonyl O atoms of enaminones correlate well with their 1H and 13C data. Shieldings of 33-45 ppm for O atoms are observed for 1 and 2 compared with 3 and 4, respectively. This is attributed to intramolecular hydrogen bonding.
- Zhuo, Jin-Cong
-
p. 311 - 322
(2007/10/03)
-
- Intramolecular Cyclization of Enaminones Involving Arylpalladium Complexes. Synthesis of Carbazoles
-
On treatment of the 3-((2-bromoaryl)amino)cyclohex-2-en-1-ones with a catalytic amount of Pd(0) species, intramolecular cyclization via arylpalladium complexes occurred to yield the 1,2-dihydrocarbazol-4(3H)-ones.Analogous products were also obtained by a
- Iida, Hideo,Yuasa, Yoshifumi,Kibayashi, Chihiro
-
p. 2938 - 2942
(2007/10/02)
-