1694-31-1Relevant articles and documents
Chemoselectivity in the Reactions of Acetylketene and Acetimidoylketene: Confirmation of Theoretical Predictions
Birney, David M.,Xu, Xiaolian,Ham, Sihyun,Huang, Xiaomeng
, p. 7114 - 7120 (1997)
Acetylketene (1) was generated by flash pyrolysis of 2,2,6-trimethyl-4H-1,3-dioxin-4-one (6). The selectivities of 1 toward a number of representative functional groups were measured for the first time in a series of competitive trapping reactions. The trend in reactivities toward 1 follows the general order amines > alcohols aldehydes ≈ ketones and can be rationalized by considering both the nucleophilicity and the electrophilicity of the reacting species. Alcohols show significant selectivity based on steric hindrance, with MeOH ≈ 1° > 2° > 3°. These selectivities are consistent with the activation energies and the pseudopericyclic transition structure previously calculated for the addition of water to formylketene. The results, presented here, of ab initio transition structure calculations for the addition of ammonia to formylketene are qualitatively consistent with the experimental trends as well. N-Propylacetacetimidoylketene (2) was generated by the solution pyrolysis of tert-butyl N-propyl-3-amino-2-butenoate (9a) and showed similar selectivity toward alcohols as opposed to ketones and similar steric discrimination toward alcohols. This is again in agreement with previous ab initio calculations. Taken together, these experimental trends in the reactivities of both 1 and 2 toward a variety of reagents provide strong, although indirect support for the planar, pseudopericyclic transition structures for these reactions which are predicted by ab initio calculations.
PORPHYRINS. 18. SYNTHESIS OF OCTAPROPYLPORPHYRIN BY THE METHOD OF MONOPYRROLE CYCLOTETRAMERIZATION OF 5-CARBOXY-2-METHOXYMETHYL-3,4-DIPROPYLPYRROLE. INVESTIGATION OF THE THERMOLYSIS OF meso-N-METHYLFORMALDIMINEOCTAPROPYLPORPHYRIN
Shul'ga, A. M.,Ponomarev, G. V.
, p. 748 - 753 (1984)
The synthesis of octapropylporphyrin on the basis of 5-carboxy-2-methoxymethyl-3,4-dipropylpyrrole was realized.It was demonstrated that in the thermolysis of meso-N-methylformaldimineoctapropylporphyrin, 31,51-cyclo-31-ethylidene- and 31,51-cyclo-31-ethyl-51-(N-methylimine) derivatives are also formed in addition to 31,51-cyclo-31-ethylheptapropylporphyrin.
Csp3-H monofluoroalkenylation via stereoselective C-F bond cleavage
Hu, Binjing,Hu, Ying,Li, Jie,Liu, Xingchen,Ren, Zhouyang
supporting information, p. 2734 - 2737 (2022/03/02)
A practical nickel- and photoredox-catalyzed Csp3-H monofluoroalkenylation through chelation-assisted Csp2-F bond cleavage of gem-difluoroalkenes for the synthesis of stereodefined tetrasubstituted fluoroalkenes has been developed. Moreover, the gem-difluoroalkenes can also undergo photoredox-catalyzed cascade twofold C-F diaminomethylation. This journal is
Revisiting ageless antiques; synthesis, biological evaluation, docking simulation and mechanistic insights of 1,4-Dihydropyridines as anticancer agents
Sidhom, Peter A.,El-Bastawissy, Eman,Salama, Abeer A.,El-Moselhy, Tarek F.
supporting information, (2021/06/21)
The historic DHP nucleus was serendipitously discovered by Arthur Hantzsch about 130 years ago and is still considered a hidden treasure for various pharmacological activities. Twenty-one DHP analogues were synthesized using the expedient one pot Hantzsch synthesis for screening as anticancer agents. Initially, the in vitro anti-proliferative single dose against a panel of 18 cancer cell lines showed that compounds 11b and 8f were the superlative candidates regarding their antitumor effect (GI% mean = 66.40% and 50.42%, correspondingly) compared to cisplatin (GI% mean = 65.58%) and doxorubicin (GI% mean = 74.56%). Remarkably, compound 11b showed a remarkable MDA-MB-468 anticancer activity (GI%=80.81%), higher than cisplatin (64.44%) and doxorubicin (76.72%), as well as strong antitumor activity against lung cancer A549 (GI%= 83.02%), more powerful than both cisplatin and doxorubicin. Compound 11b exhibited an exceptional anticancer activity against lung cancer cell line (A549) as its GI50 in nanomolar was (540 nM) with a 9-fold increase greater than cisplatin (GI50 = 4.93 μM) and with a selectivity index = 131 to cancer cells over normal cells. Further mechanistic investigations proved that DHPs anticipate simultaneously TOPI and RTKs (VEGFR-2, HER-2 and BTK) which can stimulate BAX/BAK and the executioner caspases via rtPCR studies.
Visible-light-driven radical 1,3-addition of selenosulfonates to vinyldiazo compounds
Li, Weiyu,Zhou, Lei
supporting information, p. 6652 - 6658 (2021/09/10)
Herein, we report a visible-light-driven radical 1,3-selenosulfonylation of vinyldiazo compounds with selenosulfonates, providing various γ-seleno allylic sulfones in good yields. This photochemical reaction was carried out at room temperature in an open flask using ethyl acetate as the solvent without any photocatalysts or additives. The control experiments corroborated that the 1,3-addition proceeded via a radical-chain propagation process. The synthetic applications of the resulting products were demonstrated by deselenization, reduction, bromination and allylation.
Design, synthesis, and molecular docking study of new monastrol analogues as kinesin spindle protein inhibitors
El-Hamamsy, Mervat H.,Sharafeldin, Nabaweya A.,El-Moselhy, Tarek F.,Tawfik, Haytham O.
, (2020/06/03)
Lung, colorectal, and breast cancers are the top three types of cancer by incidence and are responsible for one-third of the cancer incidence and mortality. A series of 18 3,4-dihydropyrimidine analogues bearing a 1,2-methylenedioxybenzene component at position 4 with diverse side chains at positions 5 and 6 was designed and synthesized as inhibitors of the Eg5 kinesin enzyme. Target compounds were screened for their anticancer activity according to the NCI-USA protocol toward a panel of 60 cancer cell lines. Compounds 12a and 12b displayed the best antiproliferation activity against many cell lines. Interestingly, compound 12a displayed lethal effects against non-small-cell lung cancer NCI-H522 cells (?42.26%) and MDA-MB-468 breast cancer cells (?1.10%) at a single-dose assay concentration of 10?5 M. Compounds 11c, 11d, 11g, 12a–d, 13, 15, and 18a were assayed against the kinesin enzyme, with IC50 values ranging from 1.2 to 18.71 μM, which were more potent compared with monastrol (IC50 = 20 μM). Cell cycle analysis of NCI-H522 cells treated with compound 12a showed cell cycle arrest at the G2/M phase. Furthermore, the expression levels of active caspase-3 and -9 were measured. A molecular docking study was performed for some demonstrative compounds as well as monastrol docked into the allosteric binding site of the kinesin spindle protein.
N, N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack adducts with 1,3,5-triazine compounds as efficient catalysts for the transesterification of β-ketoesters
Chityala, Yadaiah,Duguta, Govardhan,Kamatala, Chinna Rajanna,Muddam, Bhooshan,Mukka, Satish Kumar
supporting information, p. 1641 - 1655 (2020/05/25)
N, N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack (VH) adducts with 1,3,5-triazine compunds such as trichloroisocyanuric acid (TCCA) and trichlorotriazine (TCTA) were prepared by replacing classical oxy chlorides POCl3, and SOCl2, which were explored as efficient catalysts for the transesterification of β-ketoesters. The prepared (TCCA/DMF) and (TCTA/DMF) adducts improved greenery of the classical Vilsmeier–Haack reagents (POCl3/DMF), and (SOCl2/DMF), and demonstrated their better efficient catalytic ativity. Reaction times were in the range: 3.5 to 6.5 hr (SOCl2/DMF); 2.8–5.2 hr (POCl3/DMF); 2.5–5.2 hr (TCCA/DMF) and 2.5–5.0 hr (TCTA/DMF) catalytic systems. Ultrasonically (US) assisted protocols with these reagents further reduced the reaction times (two to three times), while microwave assisted (MW) protocols with these reagents were much more effective. The reactions could be completed in only few seconds (less than a minute) in MWassisted protocols as compared to US assited reactions, followed by good product yields.
General [4 + 1] Cyclization Approach to Access 2,2-Disubstituted Tetrahydrofurans Enabled by Electrophilic Bifunctional Peroxides
Gao, Min,Zhao, Yukun,Zhong, Chen,Liu, Shengshu,Liu, Pengkang,Yin, Qi,Hu, Lin
supporting information, p. 5679 - 5684 (2019/08/01)
A general [4 + 1] cyclization reaction of carbonyl nucleophiles with 2-iodomethylallyl peroxides, which function as unique electrophilic oxygen synthons, for the synthesis of a broad range of 2,2-disubstituted tetrahydrofurans is achieved under operationally simple conditions. The unprecedented asymmetric version of such reaction is also realized via chiral auxiliary-assisted cyclization, thus providing a distinct approach to access chiral tetrahydrofurans with high diastereoselectivities. The new method can be applied to the synthesis of core structure of posaconazole drug.
Synthesis method of tert-butyl acetoacetate
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Paragraph 0039-0050, (2018/05/16)
The invention discloses a synthesis method of tert-butyl acetoacetate. The method comprises the following steps that tertiary butanol and catalysts are added into a reaction container; the catalysts are selected from aliphatic amine catalysts or tertiary
Hypochlorite-Mediated Modulation of Photoinduced Electron Transfer in a Phenothiazine–Boron dipyrromethene Electron Donor–Acceptor Dyad: A Highly Water Soluble “Turn-On” Fluorescent Probe for Hypochlorite
Soni, Disha,Duvva, Naresh,Badgurjar, Deepak,Roy, Tapta Kanchan,Nimesh, Surendra,Arya, Geeta,Giribabu, Lingamallu,Chitta, Raghu
supporting information, p. 1594 - 1608 (2018/06/26)
A highly water-soluble phenothiazine (PTZ)–boron dipyrromethene (BODIPY)-based electron donor–acceptor dyad (WS-Probe), which contains BODIPY as the signaling antennae and PTZ as the OCl? reactive group, was designed and used as a fluorescent chemosensor for the detection of OCl?. Upon addition of incremental amounts of NaOCl, the quenched fluorescence of WS-Probe was enhanced drastically, which indicated the inhibition of reductive photoinduced electron transfer (PET) from PTZ to 1BODIPY*; the detection limit was calculated to be 26.7 nm. Selectivity studies with various reactive oxygen species, cations, and anions revealed that WS-Probe was able to detect OCl? selectively. Steady-state fluorescence studies performed at varied pH suggested that WS-Probe can detect NaOCl and exhibits maximum fluorescence in the pH range of 7 to 8, similar to physiological conditions. ESI-MS analysis and 1H NMR spectroscopy titrations showed the formation of sulfoxide as the major oxidized product upon addition of hypochlorite. More interestingly, when WS-Probe was treated with real water samples, the fluorescence response was clearly visible with tap water and disinfectant, which indicated the presence of OCl? in these samples. The in vitro cell viability assay performed with human embryonic kidney 293 (HEK 293) cells suggested that WS-probe is non-toxic up to 10 μm and implicates the use of the probe for biological applications.