The effects of substituent type and position on the proton transfer reaction of 3-hydroxytropolone(3-OHTRN) have been investigated theoretically by using density functional theory at the level of B3LYP/ 6-31+G** metho...The effects of substituent type and position on the proton transfer reaction of 3-hydroxytropolone(3-OHTRN) have been investigated theoretically by using density functional theory at the level of B3LYP/ 6-31+G** method. The influence of solvent on the proton transfer reactions of substituted 3-OHTRN has been examined using the self-consistent isodensity polarized continuum model(SCI-PCM) in water. As a result, while the proton transfer reaction is kinetically the easiest by substitution on position 3 of-NH2 group in the gas phase, it is kinetically the easiest by substitution on position 5 of the same group in water. In addition, these reactions are either kinetically or thermodynamically easier in the gas phase than that in water, except the reaction of structure with-NH2 group at position 6.展开更多
3-Acetyltropolone was reacted with 2-aminobenzaldehydes to afford 3- (2-quinolyl)tropolones.2-Acetyl-7-methylaminotropone and 2-acetyl-7-ethylamino- tropone were respectively reacted with 2-aminobenzaldehydes to give ...3-Acetyltropolone was reacted with 2-aminobenzaldehydes to afford 3- (2-quinolyl)tropolones.2-Acetyl-7-methylaminotropone and 2-acetyl-7-ethylamino- tropone were respectively reacted with 2-aminobenzaldehydes to give the corres- ponding 2-(2-quinolyl)-7-methylaminotropones and 2-(2-quinolyl)-7-ethylaminotro- pones,which after treatment with sodium hydroxide solution also afforded 3-(2- quinolyl)tropolones.展开更多
1 Results Tropolone,2-hydroxy-2,4,6-cycloheptatrienone,an isomer of benzoic acid,a seven-membered,non-benzenoid aromatic molecule possessing three double bonds conjugated with a carbonyl group.The studies of tropolone...1 Results Tropolone,2-hydroxy-2,4,6-cycloheptatrienone,an isomer of benzoic acid,a seven-membered,non-benzenoid aromatic molecule possessing three double bonds conjugated with a carbonyl group.The studies of tropolone forms complexes[1] with many metals became more important because of their potential application in the field of material science,agriculture and medicine.In the course of our studies on the chemistry of 5-substituted tropolone derivatives[2],the synthesis of new tropolone azo derivatives ...展开更多
Phomaketals A(1)and B(2),two tropolonic meroterpenoids with the unprecedented pentacyclic skeletons,were isolated from the solid-substrate fermentation cultures of a eupC overexpressed mutant strain of the fungus Phom...Phomaketals A(1)and B(2),two tropolonic meroterpenoids with the unprecedented pentacyclic skeletons,were isolated from the solid-substrate fermentation cultures of a eupC overexpressed mutant strain of the fungus Phoma sp.,together with a biogenetically related secondary metabolite pughiinin B(3),and the known one noreupenifeldin B(4).The structures of 1–3 were elucidated primarily by nuclear magnetic resonance(NMR)experiments.The absolute configurations of 1 and 2 were assigned by electronic circular dichroism calculations and the calculated NMR with DP4+analysis,while that of 3 was established by single-crystal X-ray diffraction analysis using Cu Kαradiation.Biogenetically,phomaketals A(1)and B(2)could be derived from the hypothetical tropolonic sesquiterpene intermediates neosetophomone B(6)and 9-R-neosetophomone B(6),respectively,via different reactions cascades.Compound 1 showed antiproliferative effect only against the SUPB15 cells,with an 50%inhibitory concentration(IC50)value of 4.85μmol/L,while the co-isolated known meroterpenoid 4 displayed potent effects against three tumor cell lines,SUPB15,EL4,and H9,showing IC50values of 0.36–27.08μmol/L.展开更多
In 1960, Palmer et al. suggested that the rates of the base-catalyzed proton exchange （deuteration, k<sub>D</sub>） at the chiral nitrogen centers of the octahedral complexes in aqueous solution increase ...In 1960, Palmer et al. suggested that the rates of the base-catalyzed proton exchange （deuteration, k<sub>D</sub>） at the chiral nitrogen centers of the octahedral complexes in aqueous solution increase with the increase of the positive charges in the complex. However, we recently found out that the rate of[Co（ox）<sub>2</sub>（Me-en）]<sup>+</sup> was about 20 times larger than that展开更多
Polymer microcapsule was employed as a reaction medium to achieve enantioselectivity in photochemical reduction of phenyl cyclohexyl ketone and photoelectrocyclization of tropolone methyl ether under the influence of ...Polymer microcapsule was employed as a reaction medium to achieve enantioselectivity in photochemical reduction of phenyl cyclohexyl ketone and photoelectrocyclization of tropolone methyl ether under the influence of various chiral inductors. In all cases, low but evident enantioselectivity was observed. The poor enantioselectivity is probably due to the facts that not all the capsules include simultaneously both the chiral inductor and the reactant molecules, and the wall of the microcapsule is not rigid enough to hold the reactant and the chiral inductor molecules in close contact.展开更多
文摘The effects of substituent type and position on the proton transfer reaction of 3-hydroxytropolone(3-OHTRN) have been investigated theoretically by using density functional theory at the level of B3LYP/ 6-31+G** method. The influence of solvent on the proton transfer reactions of substituted 3-OHTRN has been examined using the self-consistent isodensity polarized continuum model(SCI-PCM) in water. As a result, while the proton transfer reaction is kinetically the easiest by substitution on position 3 of-NH2 group in the gas phase, it is kinetically the easiest by substitution on position 5 of the same group in water. In addition, these reactions are either kinetically or thermodynamically easier in the gas phase than that in water, except the reaction of structure with-NH2 group at position 6.
文摘3-Acetyltropolone was reacted with 2-aminobenzaldehydes to afford 3- (2-quinolyl)tropolones.2-Acetyl-7-methylaminotropone and 2-acetyl-7-ethylamino- tropone were respectively reacted with 2-aminobenzaldehydes to give the corres- ponding 2-(2-quinolyl)-7-methylaminotropones and 2-(2-quinolyl)-7-ethylaminotro- pones,which after treatment with sodium hydroxide solution also afforded 3-(2- quinolyl)tropolones.
文摘1 Results Tropolone,2-hydroxy-2,4,6-cycloheptatrienone,an isomer of benzoic acid,a seven-membered,non-benzenoid aromatic molecule possessing three double bonds conjugated with a carbonyl group.The studies of tropolone forms complexes[1] with many metals became more important because of their potential application in the field of material science,agriculture and medicine.In the course of our studies on the chemistry of 5-substituted tropolone derivatives[2],the synthesis of new tropolone azo derivatives ...
基金financial support from the National Natural Science Foundation of China(No.82003628)the CAMS Innovation Fund for Medical Sciences(Nos.2021-I2M-1-030,2021-I2M-1-028,and 2021-1-I2M-2-002)。
文摘Phomaketals A(1)and B(2),two tropolonic meroterpenoids with the unprecedented pentacyclic skeletons,were isolated from the solid-substrate fermentation cultures of a eupC overexpressed mutant strain of the fungus Phoma sp.,together with a biogenetically related secondary metabolite pughiinin B(3),and the known one noreupenifeldin B(4).The structures of 1–3 were elucidated primarily by nuclear magnetic resonance(NMR)experiments.The absolute configurations of 1 and 2 were assigned by electronic circular dichroism calculations and the calculated NMR with DP4+analysis,while that of 3 was established by single-crystal X-ray diffraction analysis using Cu Kαradiation.Biogenetically,phomaketals A(1)and B(2)could be derived from the hypothetical tropolonic sesquiterpene intermediates neosetophomone B(6)and 9-R-neosetophomone B(6),respectively,via different reactions cascades.Compound 1 showed antiproliferative effect only against the SUPB15 cells,with an 50%inhibitory concentration(IC50)value of 4.85μmol/L,while the co-isolated known meroterpenoid 4 displayed potent effects against three tumor cell lines,SUPB15,EL4,and H9,showing IC50values of 0.36–27.08μmol/L.
文摘In 1960, Palmer et al. suggested that the rates of the base-catalyzed proton exchange （deuteration, k<sub>D</sub>） at the chiral nitrogen centers of the octahedral complexes in aqueous solution increase with the increase of the positive charges in the complex. However, we recently found out that the rate of[Co（ox）<sub>2</sub>（Me-en）]<sup>+</sup> was about 20 times larger than that
文摘Polymer microcapsule was employed as a reaction medium to achieve enantioselectivity in photochemical reduction of phenyl cyclohexyl ketone and photoelectrocyclization of tropolone methyl ether under the influence of various chiral inductors. In all cases, low but evident enantioselectivity was observed. The poor enantioselectivity is probably due to the facts that not all the capsules include simultaneously both the chiral inductor and the reactant molecules, and the wall of the microcapsule is not rigid enough to hold the reactant and the chiral inductor molecules in close contact.
