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2018 Volume 38 Issue 3
2018, 38(3): 541-554
doi: 10.6023/cjoc201710028
Abstract:
Helicenes are a kind of π-conjugated helical compounds which are consisted of ortho-fused benzene or other aromatic rings. Compared to other kinds of chiral catalysts, studies on helicene-based catalysts with helical chirality showed late start and lagging development. However, since helicene molecules exhibit structural rigidity, thermal stability, easily functionalization, and excellent chiral environment for asymmetric catalysis by continuous elaborate curve in three-dimensional space, investigation on the synthesis of helicene-based chiral catalysts and their applications in asymmetric catalysis have attracted increasing interest in recent years. According to the different roles of the helicenes played in the asymmetric catalysis, the helicene-based catalysts can be classified into chiral inducers, helically chiral ligands and helical organocatalysts, and their applications in asymmetric catalysis will be focused on in this review, respectively.
Helicenes are a kind of π-conjugated helical compounds which are consisted of ortho-fused benzene or other aromatic rings. Compared to other kinds of chiral catalysts, studies on helicene-based catalysts with helical chirality showed late start and lagging development. However, since helicene molecules exhibit structural rigidity, thermal stability, easily functionalization, and excellent chiral environment for asymmetric catalysis by continuous elaborate curve in three-dimensional space, investigation on the synthesis of helicene-based chiral catalysts and their applications in asymmetric catalysis have attracted increasing interest in recent years. According to the different roles of the helicenes played in the asymmetric catalysis, the helicene-based catalysts can be classified into chiral inducers, helically chiral ligands and helical organocatalysts, and their applications in asymmetric catalysis will be focused on in this review, respectively.
2018, 38(3): 555-564
doi: 10.6023/cjoc201708039
Abstract:
Halogen ions play an important role in chemistry, biology and material. The concentration of fluoride in the organism directly affects its health. The halide materials often act as flame retardant to improve the ignition point for plastic and other polymer products. So it is of great significance to detect halogen ions. Chemosensors include colorimetric and fluorescent sensors, which have the advantages of good selectivity and high sensitivity. In recent years, some halogen ion chemosensors have been reported widely. According to the type of host and guest molecules, halgen ion chemosensors mainly include fluoride ion chemosensors, iodine ion chemosensors, dual channel chemosensors and functional chemosensors. In this paper, the progress of halogen ion chemosensors in recent years is reviewed, the synthetic strategies for them are summarized and the future research direction of halogen ion chemosensors is prospected.
Halogen ions play an important role in chemistry, biology and material. The concentration of fluoride in the organism directly affects its health. The halide materials often act as flame retardant to improve the ignition point for plastic and other polymer products. So it is of great significance to detect halogen ions. Chemosensors include colorimetric and fluorescent sensors, which have the advantages of good selectivity and high sensitivity. In recent years, some halogen ion chemosensors have been reported widely. According to the type of host and guest molecules, halgen ion chemosensors mainly include fluoride ion chemosensors, iodine ion chemosensors, dual channel chemosensors and functional chemosensors. In this paper, the progress of halogen ion chemosensors in recent years is reviewed, the synthetic strategies for them are summarized and the future research direction of halogen ion chemosensors is prospected.
2018, 38(3): 565-574
doi: 10.6023/cjoc201709003
Abstract:
The catalytic transformation of amino acids is one of the important routes in utilization of amino acids in chemical and biological fields. In this review, catalytic hydrogenation from amino acids to chiral amino alcohols, catalytic decarboxylation to produce amine and nitrile, catalytic deamination to produce carboxylic acid and its derivatives, catalytic pyrolysis to produce bio-fuel and the application as heterogeneous chiral catalyst were summarized. In the catalytic hydrogenation of amino acids, Ru and Rh-based catalysts showed better catalytic performance, and the temperature was a main factor on the optical purity of the product. The decarboxylation, deamination and pyrolysis reaction required relatively high temperature, which needed a large amount of energy consumption. The search of high activity and selectivity heterogeneous catalyst to achieve the reduction of the reaction temperature and pressure is the focus of future research. As the heterogeneous chiral catalyst, the research should be focus on the efficiency, seperation and recycling of the catalyst.
The catalytic transformation of amino acids is one of the important routes in utilization of amino acids in chemical and biological fields. In this review, catalytic hydrogenation from amino acids to chiral amino alcohols, catalytic decarboxylation to produce amine and nitrile, catalytic deamination to produce carboxylic acid and its derivatives, catalytic pyrolysis to produce bio-fuel and the application as heterogeneous chiral catalyst were summarized. In the catalytic hydrogenation of amino acids, Ru and Rh-based catalysts showed better catalytic performance, and the temperature was a main factor on the optical purity of the product. The decarboxylation, deamination and pyrolysis reaction required relatively high temperature, which needed a large amount of energy consumption. The search of high activity and selectivity heterogeneous catalyst to achieve the reduction of the reaction temperature and pressure is the focus of future research. As the heterogeneous chiral catalyst, the research should be focus on the efficiency, seperation and recycling of the catalyst.
2018, 38(3): 575-584
doi: 10.6023/cjoc201709006
Abstract:
Hydrogen production by artificial photosynthetic water splitting is an efficient approach to convert solar ennergy into chemical bonds. Oxygenation of an organic substrate based on light-driven water oxidation is innovative way to mimic the oxygen evolving center (OEC) in Photosystem Ⅱ. The metal catalyst will accomplish H2O activation to generate high valent metal-oxo intermediate, which can transfer the oxygen atom to an organic substrate, during which the H atoms in H2O molecule could be released. This review is a perspective of the recent advances in oxygenation of organic substrates with water as oxygen source. In the meanwhile, research prospect on photocatalytic hydrogen production coupled with the photocatalytic oxygenation of an organic substrate for a new water splitting system has been proposed.
Hydrogen production by artificial photosynthetic water splitting is an efficient approach to convert solar ennergy into chemical bonds. Oxygenation of an organic substrate based on light-driven water oxidation is innovative way to mimic the oxygen evolving center (OEC) in Photosystem Ⅱ. The metal catalyst will accomplish H2O activation to generate high valent metal-oxo intermediate, which can transfer the oxygen atom to an organic substrate, during which the H atoms in H2O molecule could be released. This review is a perspective of the recent advances in oxygenation of organic substrates with water as oxygen source. In the meanwhile, research prospect on photocatalytic hydrogen production coupled with the photocatalytic oxygenation of an organic substrate for a new water splitting system has been proposed.
2018, 38(3): 585-593
doi: 10.6023/cjoc201709012
Abstract:
In recent years, organic synthesis in aqueous medium has become an important issues. With the discovery of effective catalysts, more and more organic reactions carried out in aqueous medium have been reported. The recent advance in organic reactions in aqueous medium is reviewed.
In recent years, organic synthesis in aqueous medium has become an important issues. With the discovery of effective catalysts, more and more organic reactions carried out in aqueous medium have been reported. The recent advance in organic reactions in aqueous medium is reviewed.
2018, 38(3): 594-611
doi: 10.6023/cjoc201710007
Abstract:
Due to the special functional structural units and important applications in many fields, the study of acridine derivatives has become a hot topic worldwide. The large conjugated ring enables these dyes to be markers for fluorescence and imaging. Thanks to the ability of embedding into DNA chain, they have a wide range of applications in medicine and other fields. These dyes have the very similar color index value to that of the natural compounds. As an alternative to metal semiconductor material, acridines have presented potential value in the field of organic semiconductor materials. In recent years, emerging of the new and simple preparation technique, such as microwave assisted synthesis, metal free catalysis, one pot synthesis, and so on, has brought more attention to the synthesis and application of acridines. In this paper, various synthetic methods of acridine derivatives since 2010 and their applications in medicine, fluorescent materials, industrial dyeing materials and electroluminescence are introduced. The work about acridines accomplished in our group is also introduced. In the end, the future prospective of synthesis and application of acridine derivatives is proposed.
Due to the special functional structural units and important applications in many fields, the study of acridine derivatives has become a hot topic worldwide. The large conjugated ring enables these dyes to be markers for fluorescence and imaging. Thanks to the ability of embedding into DNA chain, they have a wide range of applications in medicine and other fields. These dyes have the very similar color index value to that of the natural compounds. As an alternative to metal semiconductor material, acridines have presented potential value in the field of organic semiconductor materials. In recent years, emerging of the new and simple preparation technique, such as microwave assisted synthesis, metal free catalysis, one pot synthesis, and so on, has brought more attention to the synthesis and application of acridines. In this paper, various synthetic methods of acridine derivatives since 2010 and their applications in medicine, fluorescent materials, industrial dyeing materials and electroluminescence are introduced. The work about acridines accomplished in our group is also introduced. In the end, the future prospective of synthesis and application of acridine derivatives is proposed.
2018, 38(3): 612-628
doi: 10.6023/cjoc201709020
Abstract:
Among the numerous bio-active species which are involved in the various chemical reactions in our body, reactive oxygen species (ROS) are a class of important biological species, which are oxidative. ROS can maintain the intracellular redox balance and are tightly related with the cell growth and death. Hence, the fluorescence detection of intracellular ROS has attracted wide attention. However, owining to the inherent features of ROS, such as the short lifetime and high reactivity, fluorescence analysis of ROS is always faced with some problems, like low selectivity and side reactions. Herein, the development of small molecular fluorescent probes for intracellular ROS over the past decade is summarized, and the design mechanisms and bio-applications of these probes are emphasized.
Among the numerous bio-active species which are involved in the various chemical reactions in our body, reactive oxygen species (ROS) are a class of important biological species, which are oxidative. ROS can maintain the intracellular redox balance and are tightly related with the cell growth and death. Hence, the fluorescence detection of intracellular ROS has attracted wide attention. However, owining to the inherent features of ROS, such as the short lifetime and high reactivity, fluorescence analysis of ROS is always faced with some problems, like low selectivity and side reactions. Herein, the development of small molecular fluorescent probes for intracellular ROS over the past decade is summarized, and the design mechanisms and bio-applications of these probes are emphasized.
2018, 38(3): 629-635
doi: 10.6023/cjoc201709040
Abstract:
A novel CN- chemosensor based N-4-pyridylcoumarin-3-carboxamide derivative Q1 was designed and synthesized. The recognition performance of sensor Q1 for ten different anions was studied by UV and fluorescence spectroscopy. When anions such as CN-, F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, ClO4- and SCN- were added to the mixed solution (DMSO/H2O, V:V=9:1), addition of CN- could increase the absorption peak of Q1 at 304 nm, and the corresponding fluorescence produced a strong emission peak at 431 nm. Q1 solution with CN- emitted strong blue fluorescent that can be easily observed by naked eyes. The color changed (from colorless to faint yellow) and the "Turn-On" fluorescence behavior suggested that Q1 could detect CN- by dual-channel. Happily, the fluorescent limit of detection (LOD) is 1.44×10-8 mol/L, was lower than the specified content by World Health Organization (WHO) in drinking water. Based on all the experimental facts, we speculated that the possible identification mechanism was that the addition reaction took place between Q1 and CN-, and it can also be confirmed by density functional theory (DFT). This result can be applied to the detection of CN- in cherry kernel.
A novel CN- chemosensor based N-4-pyridylcoumarin-3-carboxamide derivative Q1 was designed and synthesized. The recognition performance of sensor Q1 for ten different anions was studied by UV and fluorescence spectroscopy. When anions such as CN-, F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, ClO4- and SCN- were added to the mixed solution (DMSO/H2O, V:V=9:1), addition of CN- could increase the absorption peak of Q1 at 304 nm, and the corresponding fluorescence produced a strong emission peak at 431 nm. Q1 solution with CN- emitted strong blue fluorescent that can be easily observed by naked eyes. The color changed (from colorless to faint yellow) and the "Turn-On" fluorescence behavior suggested that Q1 could detect CN- by dual-channel. Happily, the fluorescent limit of detection (LOD) is 1.44×10-8 mol/L, was lower than the specified content by World Health Organization (WHO) in drinking water. Based on all the experimental facts, we speculated that the possible identification mechanism was that the addition reaction took place between Q1 and CN-, and it can also be confirmed by density functional theory (DFT). This result can be applied to the detection of CN- in cherry kernel.
2018, 38(3): 642-647
doi: 10.6023/cjoc201708028
Abstract:
Chiral urea derivatives as organocatalysts were applied in the asymmetric aza-Friedel-Crafts reaction of α-naphthol with 14 N-tosyl aldimines. The desired chiral aminoarylnaphthols were obtained in 70%~86% yields with up to 78% enantiomeric excess (ee) under the screened optimal condition. The catalyst type and the substrate scope were broadened in this methodology.
Chiral urea derivatives as organocatalysts were applied in the asymmetric aza-Friedel-Crafts reaction of α-naphthol with 14 N-tosyl aldimines. The desired chiral aminoarylnaphthols were obtained in 70%~86% yields with up to 78% enantiomeric excess (ee) under the screened optimal condition. The catalyst type and the substrate scope were broadened in this methodology.
2018, 38(3): 665-671
doi: 10.6023/cjoc201709030
Abstract:
In order to find more efficient and economical antitumor drugs, a series of novel 1, 2, 3-triazolo[4, 5-d]pyrimidine derivatives were synthesized and evaluated for their antitumor activities against five human cancer cell lines (MGC-803, MCF-7, EC-109, PC-3 and Hela) in vitro. The results showed that most compounds had good antitumor activities, especially 5-(((1H-benzo[d]imidazol-2-yl)methyl)thio)-3-bezyl-N-(4-chlorophenyl)-3H-[1, 2, 3]triazolo[4, 5-d]pyrimidin-7-amine (11b) and 2, 2'-((5-(((1H-benzo[d]imidazol-2-yl)methyl)thio)-3-benzyl-3H-[1, 2, 3]triazolo[4, 5-d]pyrimidin-7-yl)azanediyl)bis(ethan-1-ol) (11m) exhibited better antitumor activities than 5-fluorouracil against MGC-803 and Hela.
In order to find more efficient and economical antitumor drugs, a series of novel 1, 2, 3-triazolo[4, 5-d]pyrimidine derivatives were synthesized and evaluated for their antitumor activities against five human cancer cell lines (MGC-803, MCF-7, EC-109, PC-3 and Hela) in vitro. The results showed that most compounds had good antitumor activities, especially 5-(((1H-benzo[d]imidazol-2-yl)methyl)thio)-3-bezyl-N-(4-chlorophenyl)-3H-[1, 2, 3]triazolo[4, 5-d]pyrimidin-7-amine (11b) and 2, 2'-((5-(((1H-benzo[d]imidazol-2-yl)methyl)thio)-3-benzyl-3H-[1, 2, 3]triazolo[4, 5-d]pyrimidin-7-yl)azanediyl)bis(ethan-1-ol) (11m) exhibited better antitumor activities than 5-fluorouracil against MGC-803 and Hela.
2018, 38(3): 636-641
doi: 10.6023/cjoc201709017
Abstract:
A turn-on probe, which exhibited highly selective and sensitive signaling behaviors toward Fe3+ over other common metal ions, has been synthesized and confirmed by 1H NMR, 13C NMR, IR and MS. The addition of Fe3+ to the solution of probe induced a remarkable UV-Vis and fluorescence enhancement along with obvious color change detected by the naked eye. The reaction mechanism was also investigated and proposed as that the probe complexed Fe3+ via a 1:1 binding mode, and the subsequent complexation caused the ring-opening of the rhodamine spirolactam and thereby the changes of absorbance and fluorescence. These remarkable properties may allow Fe3+ to be detected directly in the presence of the other examined competing metal ions. Then, cells experiments showed that the probe could permeate through cell membranes and react to Fe3+ within living cells. Additionally, the probe was further used for detecting Fe3+ ions in living mouse which exhibited excellent fluorescence imaging.
A turn-on probe, which exhibited highly selective and sensitive signaling behaviors toward Fe3+ over other common metal ions, has been synthesized and confirmed by 1H NMR, 13C NMR, IR and MS. The addition of Fe3+ to the solution of probe induced a remarkable UV-Vis and fluorescence enhancement along with obvious color change detected by the naked eye. The reaction mechanism was also investigated and proposed as that the probe complexed Fe3+ via a 1:1 binding mode, and the subsequent complexation caused the ring-opening of the rhodamine spirolactam and thereby the changes of absorbance and fluorescence. These remarkable properties may allow Fe3+ to be detected directly in the presence of the other examined competing metal ions. Then, cells experiments showed that the probe could permeate through cell membranes and react to Fe3+ within living cells. Additionally, the probe was further used for detecting Fe3+ ions in living mouse which exhibited excellent fluorescence imaging.
2018, 38(3): 656-664
doi: 10.6023/cjoc201709018
Abstract:
A porous organic polymer (POP) with chiral 2, 2'-bis(diphenylphosphino)-1, 1'-binaphthalene (BINAP) has been prepared and characterized by several techniques including 13C CP/MAS NMR, 31P CP/MAS NMR, fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption. The material exhibits amorphous microporous structure. After loading of ruthenium(Ⅱ) species via coordination, the composite material Ru/POP-BINAP could be used as a heterogeneous catalyst for the asymmetric hydrogenation of β-keto esters with high activity, excellent enantioselectivity and recyclability.
A porous organic polymer (POP) with chiral 2, 2'-bis(diphenylphosphino)-1, 1'-binaphthalene (BINAP) has been prepared and characterized by several techniques including 13C CP/MAS NMR, 31P CP/MAS NMR, fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption. The material exhibits amorphous microporous structure. After loading of ruthenium(Ⅱ) species via coordination, the composite material Ru/POP-BINAP could be used as a heterogeneous catalyst for the asymmetric hydrogenation of β-keto esters with high activity, excellent enantioselectivity and recyclability.
2018, 38(3): 672-676
doi: 10.6023/cjoc201710004
Abstract:
The optically active diaryl alcohols bearing thienyl group are well-known for their biological activity as well as key substructure in bioactive compounds and pharmaceuticals. The asymmetric addition of 3-thienyl aluminum to ketones afforded the optically active 3-thienyl arylethanols in good yields with high enantioselectivities of up to 91% ee employing the simple titanium catalytic system of (S)-1, 1'-binaphthol. The catalytic system could also suit for various ketones bearing an electron-donating or electron-withdrawing groups to afford the corresponding diarylethanols containing substituted 3-thienyl groups.
The optically active diaryl alcohols bearing thienyl group are well-known for their biological activity as well as key substructure in bioactive compounds and pharmaceuticals. The asymmetric addition of 3-thienyl aluminum to ketones afforded the optically active 3-thienyl arylethanols in good yields with high enantioselectivities of up to 91% ee employing the simple titanium catalytic system of (S)-1, 1'-binaphthol. The catalytic system could also suit for various ketones bearing an electron-donating or electron-withdrawing groups to afford the corresponding diarylethanols containing substituted 3-thienyl groups.
2018, 38(3): 677-683
doi: 10.6023/cjoc201706038
Abstract:
A triphenylphosphine mediated direct trifluoromethylthiolation of indolizine and pyrrole by trifluoromethanesulfonyl chloride was developed. The readily accessable reagents and transition metal-free reaction conditions allowed this protocol applicable for large scales synthesis.
A triphenylphosphine mediated direct trifluoromethylthiolation of indolizine and pyrrole by trifluoromethanesulfonyl chloride was developed. The readily accessable reagents and transition metal-free reaction conditions allowed this protocol applicable for large scales synthesis.
2018, 38(3): 648-655
doi: 10.6023/cjoc201708031
Abstract:
Resveratrol is a type of natural phenol with a broad range of good biological activities. Based on former work, in order to look for new anticancer agents, a series of novel amide compounds between resveratrol and chalcone possessing piperazine moiety have been synthesized by connecting principle of active biological groups. The structures of compounds were characterized by IR, 1H NMR, 13C NMR and HRMS, and in vitro cytotoxic activity was evaluated against a panel of human tumor cell lines (Hela, A549 and SGC7901) by the 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The results demonstrated that amide compounds contributed good cytotoxic activity. Especially, (E)-3-(2, 4-dimethoxy-6-((E)-4-methoxystyryl)phenyl)-1-(4-(N-acryloyl)piperazin-1-yl)phenylprop-2-en-1-one (9) showed the best cytotoxic activity against A549 and Hela (IC50=0.26 and 7.35 μmol·L-1, respectively), and fluorescence-activated cell sorter (FACs) analysis showed that compound 9 significantly induced apoptosis in A549 cell.
Resveratrol is a type of natural phenol with a broad range of good biological activities. Based on former work, in order to look for new anticancer agents, a series of novel amide compounds between resveratrol and chalcone possessing piperazine moiety have been synthesized by connecting principle of active biological groups. The structures of compounds were characterized by IR, 1H NMR, 13C NMR and HRMS, and in vitro cytotoxic activity was evaluated against a panel of human tumor cell lines (Hela, A549 and SGC7901) by the 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The results demonstrated that amide compounds contributed good cytotoxic activity. Especially, (E)-3-(2, 4-dimethoxy-6-((E)-4-methoxystyryl)phenyl)-1-(4-(N-acryloyl)piperazin-1-yl)phenylprop-2-en-1-one (9) showed the best cytotoxic activity against A549 and Hela (IC50=0.26 and 7.35 μmol·L-1, respectively), and fluorescence-activated cell sorter (FACs) analysis showed that compound 9 significantly induced apoptosis in A549 cell.
2018, 38(3): 684-691
doi: 10.6023/cjoc201707034
Abstract:
A series of novel substituted chalcone-piperazine derivatives have been synthesized, and screened in vitro anti-inflammatory in lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages and cytotoxic activity against 3 strains human tumor cell lines. The results demonstrated that the substituents of the core ring and the NH group of piperazine ring had obvious influences on biological activities. Especially, 3, 4, 5-trimethoxy-4'-[N-(2-oxopropyl)-1-piperazinyl]chalcone (11) showed better inhibitory effect on the generation of NO (IC50=3.81 μmol/L), and 4-bromo-4'-[N-(4'-methyl-2-oxophenylethyl)-1-piperazinyl]chalcone (25) displayed good cytotoxic activity against A549, Hela and sk-ov-3 (IC50=0.54, 0.05 and 9.12 μmol/L, respectively).
A series of novel substituted chalcone-piperazine derivatives have been synthesized, and screened in vitro anti-inflammatory in lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages and cytotoxic activity against 3 strains human tumor cell lines. The results demonstrated that the substituents of the core ring and the NH group of piperazine ring had obvious influences on biological activities. Especially, 3, 4, 5-trimethoxy-4'-[N-(2-oxopropyl)-1-piperazinyl]chalcone (11) showed better inhibitory effect on the generation of NO (IC50=3.81 μmol/L), and 4-bromo-4'-[N-(4'-methyl-2-oxophenylethyl)-1-piperazinyl]chalcone (25) displayed good cytotoxic activity against A549, Hela and sk-ov-3 (IC50=0.54, 0.05 and 9.12 μmol/L, respectively).
2018, 38(3): 692-697
doi: 10.6023/cjoc201709039
Abstract:
A simple and rapid method is developed for the oxidation of thiols to the corresponding disulfides using N-fluorobenzenesulfonimide (NFSI) as the oxidant without any contamination by over oxidation. The synthetic protocol for disulfide bond formation proceeded efficiently under external base-and metal-free conditions with the advantages of simple operation, mild reaction conditions as well as short reaction times.
A simple and rapid method is developed for the oxidation of thiols to the corresponding disulfides using N-fluorobenzenesulfonimide (NFSI) as the oxidant without any contamination by over oxidation. The synthetic protocol for disulfide bond formation proceeded efficiently under external base-and metal-free conditions with the advantages of simple operation, mild reaction conditions as well as short reaction times.
2018, 38(3): 698-704
doi: 10.6023/cjoc201706010
Abstract:
A phosphorus ligand containing PNP and P-O structure was synthesized by substitution reaction of 5-amino-o-cresol with chlorodiphenylphosphine and its structure was conformed. Its in situ prepared complex with Cr(acac)3 and preformed complex with CrCl3(THF)3 were used as main catalysts in catalyzing ethylene oligomerization, accompanied with methylaluminoxane (MAO) as cocatalyst. The effects of solvent, temperature, pressure and Al/Cr molar ratio on the activity and selectivity of the catalyst were investigated and compared with the in situ formation of 2-aminophenol and 4-aminophenol phosphine ligands catalytic system of catalyzing ethylene oligomerization effect. The experimental results showed that the activity reached 5.91×106 g/(mol·Cr·h), when the reaction was carried at 50℃ with reaction pressure of 2.5 MPa and the Al/Cr molar ratio of 700. The selectivity of 1-octene was 72.94% and the total selectivity of 1-hexene and 1-octene was 82.11%.
A phosphorus ligand containing PNP and P-O structure was synthesized by substitution reaction of 5-amino-o-cresol with chlorodiphenylphosphine and its structure was conformed. Its in situ prepared complex with Cr(acac)3 and preformed complex with CrCl3(THF)3 were used as main catalysts in catalyzing ethylene oligomerization, accompanied with methylaluminoxane (MAO) as cocatalyst. The effects of solvent, temperature, pressure and Al/Cr molar ratio on the activity and selectivity of the catalyst were investigated and compared with the in situ formation of 2-aminophenol and 4-aminophenol phosphine ligands catalytic system of catalyzing ethylene oligomerization effect. The experimental results showed that the activity reached 5.91×106 g/(mol·Cr·h), when the reaction was carried at 50℃ with reaction pressure of 2.5 MPa and the Al/Cr molar ratio of 700. The selectivity of 1-octene was 72.94% and the total selectivity of 1-hexene and 1-octene was 82.11%.
2018, 38(3): 705-709
doi: 10.6023/cjoc201709048
Abstract:
Due to high selective coordination ability of phosphate anion to the Zn center of pincer type terpyridine zinc nitrate complexes, intriguing visual recognition of phosphate anion via selective metallo-hydrogel formation has been successfully realized. Based on this interesting result, a series of control experiments were conducted including the study on thermodynamic stability, rheological property and microscopic morphology of the metallo-hydrogel, a plausible mechanism of the discrimination was proposed.
Due to high selective coordination ability of phosphate anion to the Zn center of pincer type terpyridine zinc nitrate complexes, intriguing visual recognition of phosphate anion via selective metallo-hydrogel formation has been successfully realized. Based on this interesting result, a series of control experiments were conducted including the study on thermodynamic stability, rheological property and microscopic morphology of the metallo-hydrogel, a plausible mechanism of the discrimination was proposed.
2018, 38(3): 710-714
doi: 10.6023/cjoc201709008
Abstract:
Five isoflavonoids were isolated from the roots of the Ficus auriculata by means of silica gel column, HPLC and other chromatography methods. By using spectroscopic techniques including NMR, IR and UV, their structures were identified as 5, 7, 4'-trihydroxy-8-(1-hydroxy-2, 3-epoxy-3-methylbutyl)isoflavone (1), 5, 7, 4'-trihydroxy-3'-(2, 6, 7-trihydroxy-3-methylene-7-methyloctyl)isoflavone (2), 5, 7, 4'-trihydroxy-6-[(S)-2, 3-dihydroxy-3-methylbutyl]isoflavone (3), 5, 7, 4'-trihydroxy-6-pre-nylisoflavone (4), and 5, 7, 4'-trihydroxy-3'-prenylisoflavone (5). Compounds 1 and 2 were new isoflavonoids. All compounds were evaluated for their anti osteoporosis activities in vitro. Compounds 4 and 5 showed moderate proliferation function of primary osteoblasts in 100 μmol/L.
Five isoflavonoids were isolated from the roots of the Ficus auriculata by means of silica gel column, HPLC and other chromatography methods. By using spectroscopic techniques including NMR, IR and UV, their structures were identified as 5, 7, 4'-trihydroxy-8-(1-hydroxy-2, 3-epoxy-3-methylbutyl)isoflavone (1), 5, 7, 4'-trihydroxy-3'-(2, 6, 7-trihydroxy-3-methylene-7-methyloctyl)isoflavone (2), 5, 7, 4'-trihydroxy-6-[(S)-2, 3-dihydroxy-3-methylbutyl]isoflavone (3), 5, 7, 4'-trihydroxy-6-pre-nylisoflavone (4), and 5, 7, 4'-trihydroxy-3'-prenylisoflavone (5). Compounds 1 and 2 were new isoflavonoids. All compounds were evaluated for their anti osteoporosis activities in vitro. Compounds 4 and 5 showed moderate proliferation function of primary osteoblasts in 100 μmol/L.
