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2017 Volume 37 Issue 12
2017, 37(12): 3039-3059
doi: 10.6023/cjoc201704034
Abstract:
Iridium-catalyzed asymmetric allylic substitution reaction is one of the most important methods for the synthesis of chiral compounds. The recent research progress in iridium-catalyzed asymmetric allylic substitution reactions of allylic ester and its derivatives is reviewed with focus on the influences of the iridium catalysts, the substrate structures of allylic ester and its derivatives, the type of nucleophiles, the effects of solvents and additives on asymmetric substitution reaction. Moreover, the possible mechanisms are also discussed in this review.
Iridium-catalyzed asymmetric allylic substitution reaction is one of the most important methods for the synthesis of chiral compounds. The recent research progress in iridium-catalyzed asymmetric allylic substitution reactions of allylic ester and its derivatives is reviewed with focus on the influences of the iridium catalysts, the substrate structures of allylic ester and its derivatives, the type of nucleophiles, the effects of solvents and additives on asymmetric substitution reaction. Moreover, the possible mechanisms are also discussed in this review.
2017, 37(12): 3060-3075
doi: 10.6023/cjoc201709011
Abstract:
Trifluoromethyl can increase the chemical and metabolic stability of drugs, improve its lipophilicity and bioavailability, and furthermore, enhance drug binding selectivities. Sodium trifluoromethanesulfinate (CF3SO2Na) is a stable inexpensive reagent, which has been widely used in the field of organic fluorine chemistry. The recent progress (2014~2017) in trifluoromethylation by employing CF3SO2Na as the trifluoromethyl source is summarized. In addition, the reactions of bifunctionalization, trifluoromethylation of aromatics, trifluoromethylthioization and other types of reactions are described respectively, with their applications and reaction mechanism. It is hoped that this review can be referred to in the studies of trifluoromethyl introduction.
Trifluoromethyl can increase the chemical and metabolic stability of drugs, improve its lipophilicity and bioavailability, and furthermore, enhance drug binding selectivities. Sodium trifluoromethanesulfinate (CF3SO2Na) is a stable inexpensive reagent, which has been widely used in the field of organic fluorine chemistry. The recent progress (2014~2017) in trifluoromethylation by employing CF3SO2Na as the trifluoromethyl source is summarized. In addition, the reactions of bifunctionalization, trifluoromethylation of aromatics, trifluoromethylthioization and other types of reactions are described respectively, with their applications and reaction mechanism. It is hoped that this review can be referred to in the studies of trifluoromethyl introduction.
2017, 37(12): 3076-3084
doi: 10.6023/cjoc201707027
Abstract:
Copper ion plays an important role in various physiological processes. The imbalance of copper ion concentration in the organism can cause some corresponding diseases, so it is very important to study copper ion. The dual chemosensor refers to a class of chemosensor that can identify selectively two kinds of different ions or molecules. Compared with single-channel chemosensor, dual chemosensor have the advantage of functional diversity. In recent years, some dual chemosensors with copper ion as host and guest has been reported widely. Based on this, the progress of dual chemosensors with copper ion as a host and guest in recent years is reviewed.
Copper ion plays an important role in various physiological processes. The imbalance of copper ion concentration in the organism can cause some corresponding diseases, so it is very important to study copper ion. The dual chemosensor refers to a class of chemosensor that can identify selectively two kinds of different ions or molecules. Compared with single-channel chemosensor, dual chemosensor have the advantage of functional diversity. In recent years, some dual chemosensors with copper ion as host and guest has been reported widely. Based on this, the progress of dual chemosensors with copper ion as a host and guest in recent years is reviewed.
2017, 37(12): 3085-3095
doi: 10.6023/cjoc201705043
Abstract:
Molecular recognition is an important part of supramolecular chemistry, including cation recognition, anion recognition and neutral molecular recognition. Because of its unique structure and chemical properties, 1, 2, 3-trizoles is widely used in various fields of supramolecular chemistry. According to the classification of cation recognition, anion recognition, neutral molecular and biomacromolecule recognition, the applications of 1, 2, 3-trizole derivatives in molecular recognition are reviewed.
Molecular recognition is an important part of supramolecular chemistry, including cation recognition, anion recognition and neutral molecular recognition. Because of its unique structure and chemical properties, 1, 2, 3-trizoles is widely used in various fields of supramolecular chemistry. According to the classification of cation recognition, anion recognition, neutral molecular and biomacromolecule recognition, the applications of 1, 2, 3-trizole derivatives in molecular recognition are reviewed.
2017, 37(12): 3096-3111
doi: 10.6023/cjoc201706004
Abstract:
Compared with sequential reactions, domino reactions are more efficient and highly desirable in organic synthesis as fewer operational and purification procedures are involved, yielding the product with complexity in a more economic and environmently friendly manner. Domino reactions induced by copper-catalyzed hydrocupration of unsaturated C-C bonds in α, β-unsaturated ketones, α, β-unsaturated carboxylates, aryl alkenes, aliphatic alkenes and even alkynes are reviewed. A hydrosilane is used as a hydride source for CuH formation and the hydrocupration intermediates undergo subsequent addition to polar unsaturated bonds, e.g. carbonyls and imines, or proceed to substitution reactions, and finally, reaction involving two or more newly formed bonds proceed without purification of intermediate products or changing the operational conditions. Because of its simplicity and efficiency, this method is highly valuable in organic synthesis.
Compared with sequential reactions, domino reactions are more efficient and highly desirable in organic synthesis as fewer operational and purification procedures are involved, yielding the product with complexity in a more economic and environmently friendly manner. Domino reactions induced by copper-catalyzed hydrocupration of unsaturated C-C bonds in α, β-unsaturated ketones, α, β-unsaturated carboxylates, aryl alkenes, aliphatic alkenes and even alkynes are reviewed. A hydrosilane is used as a hydride source for CuH formation and the hydrocupration intermediates undergo subsequent addition to polar unsaturated bonds, e.g. carbonyls and imines, or proceed to substitution reactions, and finally, reaction involving two or more newly formed bonds proceed without purification of intermediate products or changing the operational conditions. Because of its simplicity and efficiency, this method is highly valuable in organic synthesis.
2017, 37(12): 3112-3129
doi: 10.6023/cjoc201706006
Abstract:
Transition metal catalyzed C-H activation/C-O coupling reaction of arenes serves as a powerful strategy for constructing phenols, aryl ethers and phenolic esters, and thus represents a hot topic in the field of organic chemistry. This strategy is effective and atom-economic as it allows people to construct C-O bond directly from arenes, avoiding pre-functionalization of arenes. Recent development on transition metal catalyzed C-H activation/C-O coupling reactions according to different species of transition metal catalysts is summarized. Possible mechanisms of typical protocols are explained and compared. Existing problems and limitations, and a brief outlook in this field is also presented.
Transition metal catalyzed C-H activation/C-O coupling reaction of arenes serves as a powerful strategy for constructing phenols, aryl ethers and phenolic esters, and thus represents a hot topic in the field of organic chemistry. This strategy is effective and atom-economic as it allows people to construct C-O bond directly from arenes, avoiding pre-functionalization of arenes. Recent development on transition metal catalyzed C-H activation/C-O coupling reactions according to different species of transition metal catalysts is summarized. Possible mechanisms of typical protocols are explained and compared. Existing problems and limitations, and a brief outlook in this field is also presented.
2017, 37(12): 3130-3145
doi: 10.6023/cjoc201704050
Abstract:
Carbonyl group is one of the important building blocks in organic synthesis. The catalytic Markovnikov hydration of alkynes is an eco-friendly reaction with 100% atom economy to construct carbonyl compounds, and is one of hot spots of organic chemistry over recent years. Research progress concerning catalytic hydration of alkynes to ketones on the view of the types of catalysts, and catalytic mechanisms are concluded. Finally, the further development and challenge of catalytic hydration of alkynes are dis-cussed.
Carbonyl group is one of the important building blocks in organic synthesis. The catalytic Markovnikov hydration of alkynes is an eco-friendly reaction with 100% atom economy to construct carbonyl compounds, and is one of hot spots of organic chemistry over recent years. Research progress concerning catalytic hydration of alkynes to ketones on the view of the types of catalysts, and catalytic mechanisms are concluded. Finally, the further development and challenge of catalytic hydration of alkynes are dis-cussed.
2017, 37(12): 3146-3154
doi: 10.6023/cjoc201708010
Abstract:
Sulfonamides as an important type of chemotherapeutic drugs have been one of the research topics recently. A series of sulfonamide 1, 2, 4-triazoles were successfully synthesized starting from commercial acetanilide via a multi-step sequence of sulfonylation, aminolysis and N-alkylation, and were confirmed by IR, 1H NMR, 13C NMR, MS as well as HRMS spectra. All the synthesized new compounds were evaluated for their in vitro antibacterial and antifungal activities. The bioactive assay showed that most of the synthesized compounds exhibited better inhibitory potency than sulfanilamide against all tested bacterial strains, and most of the compounds gave good anti-Escherichia coli activity in comparison with other microorganisms. Especially, N-(4-(N-(2-(1H-1, 2, 4-triazol-1-yl)ethyl)-N-(3-fluorobenzyl)sulfamoyl)phenyl) acetamide (7b) bearing m-fluorobenzyl group exhibited excellent antibacterial activities against Escherichia coli with minimal inhibition concentration (MIC) value of 16 mg/mL. Preliminary research revealed that compound 7b could effectively intercalate into calf thymus DNA to form compound 7b-DNA complex which might block DNA replication and thus exert antimicrobial activities.
Sulfonamides as an important type of chemotherapeutic drugs have been one of the research topics recently. A series of sulfonamide 1, 2, 4-triazoles were successfully synthesized starting from commercial acetanilide via a multi-step sequence of sulfonylation, aminolysis and N-alkylation, and were confirmed by IR, 1H NMR, 13C NMR, MS as well as HRMS spectra. All the synthesized new compounds were evaluated for their in vitro antibacterial and antifungal activities. The bioactive assay showed that most of the synthesized compounds exhibited better inhibitory potency than sulfanilamide against all tested bacterial strains, and most of the compounds gave good anti-Escherichia coli activity in comparison with other microorganisms. Especially, N-(4-(N-(2-(1H-1, 2, 4-triazol-1-yl)ethyl)-N-(3-fluorobenzyl)sulfamoyl)phenyl) acetamide (7b) bearing m-fluorobenzyl group exhibited excellent antibacterial activities against Escherichia coli with minimal inhibition concentration (MIC) value of 16 mg/mL. Preliminary research revealed that compound 7b could effectively intercalate into calf thymus DNA to form compound 7b-DNA complex which might block DNA replication and thus exert antimicrobial activities.
2017, 37(12): 3155-3162
doi: 10.6023/cjoc201708020
Abstract:
In order to find novel pyrazole oxime ethers with good bioactivities, a series of novel pyrazole oxime ether compounds containing substituted pyrazole moiety were designed and synthesized according to the method of active substructure combination. Their structures were characterized by 1H NMR, 13C NMR, and elemental analysis. Preliminary bioassay displayed that most target compounds had good insecticidal activities. At the concentration of 500 μg/mL, sixteen compounds showed insecticidal activity against Oriental armyworm with 80%~100%, fourteen compounds exhibited insecticidal activity against Aphis medicaginis with 80%~100%, and twelve compounds showed insecticidal activity against Nilaparvata lugens with 70%~100%. When the dosage was lowered to 100 μg/mL, five compounds still possessed inhibitory effect against Aphis medicaginis with 50%~80%.
In order to find novel pyrazole oxime ethers with good bioactivities, a series of novel pyrazole oxime ether compounds containing substituted pyrazole moiety were designed and synthesized according to the method of active substructure combination. Their structures were characterized by 1H NMR, 13C NMR, and elemental analysis. Preliminary bioassay displayed that most target compounds had good insecticidal activities. At the concentration of 500 μg/mL, sixteen compounds showed insecticidal activity against Oriental armyworm with 80%~100%, fourteen compounds exhibited insecticidal activity against Aphis medicaginis with 80%~100%, and twelve compounds showed insecticidal activity against Nilaparvata lugens with 70%~100%. When the dosage was lowered to 100 μg/mL, five compounds still possessed inhibitory effect against Aphis medicaginis with 50%~80%.
2017, 37(12): 3163-3169
doi: 10.6023/cjoc201707003
Abstract:
The catalytic asymmetric one-pot tandem intermolecular olefin cross-metathesis/intramolecular Friedel-Crafts alkylation with aryloxy-and arylamino-tethered enals as building blocks was developed, which offers a direct and convenient access to a novel type of pyrrole-fused heterocyclic compounds in good yields with synthetically useful enantioselectivities.
The catalytic asymmetric one-pot tandem intermolecular olefin cross-metathesis/intramolecular Friedel-Crafts alkylation with aryloxy-and arylamino-tethered enals as building blocks was developed, which offers a direct and convenient access to a novel type of pyrrole-fused heterocyclic compounds in good yields with synthetically useful enantioselectivities.
2017, 37(12): 3170-3176
doi: 10.6023/cjoc201708001
Abstract:
[Cp*Ir-(di-OH-bpy)(OH2)] [SO4] (di-OH-bpy=4, 4'-dihydroxyl-2, 2'-bipyridine) exhibited high catalytic performance during the hydrogenation of D-glucose to D-sorbitol. Using formic acid as hydrogen source led to an unsatisfactory D-sorbitol selectivity. The ring-opening hydrogenation of glucose was efficiently achieved by hydrogen. Under optimal conditions, D-sorbitol could be obtained in 96% yield. The effect of different ligands in iridium catalyst on hydrogenation was also investigated. A speculated mechanism was proposed to illustrate the detailed process of D-glucose hydrogenation to produce sorbitol. The catalytic system has the merits of relatively mild reaction conditions and high product selectivity, which provides an effective method for the catalytic hydrogenation of other biomass-based platform chemicals.
[Cp*Ir-(di-OH-bpy)(OH2)] [SO4] (di-OH-bpy=4, 4'-dihydroxyl-2, 2'-bipyridine) exhibited high catalytic performance during the hydrogenation of D-glucose to D-sorbitol. Using formic acid as hydrogen source led to an unsatisfactory D-sorbitol selectivity. The ring-opening hydrogenation of glucose was efficiently achieved by hydrogen. Under optimal conditions, D-sorbitol could be obtained in 96% yield. The effect of different ligands in iridium catalyst on hydrogenation was also investigated. A speculated mechanism was proposed to illustrate the detailed process of D-glucose hydrogenation to produce sorbitol. The catalytic system has the merits of relatively mild reaction conditions and high product selectivity, which provides an effective method for the catalytic hydrogenation of other biomass-based platform chemicals.
2017, 37(12): 3177-3185
doi: 10.6023/cjoc201704036
Abstract:
A series of multi-substituted oxazolidin-2-(thi)one derivatives were prepared via 1, 8-diazabicyclo[5.4.0]undec-7-ene (DBU) promoted nucleophilic addition/cyclization from alkynyl alcohol and isocynate or thiocynate in high yields of 75%~95%. This concise and efficient approach provides a facial access to a library of biological (Z)-arylmethylene substituted oxazolidin-2-(thi)one derivatives with high stereo-selectivities.
A series of multi-substituted oxazolidin-2-(thi)one derivatives were prepared via 1, 8-diazabicyclo[5.4.0]undec-7-ene (DBU) promoted nucleophilic addition/cyclization from alkynyl alcohol and isocynate or thiocynate in high yields of 75%~95%. This concise and efficient approach provides a facial access to a library of biological (Z)-arylmethylene substituted oxazolidin-2-(thi)one derivatives with high stereo-selectivities.
2017, 37(12): 3191-3197
doi: 10.6023/cjoc201706015
Abstract:
The reactions between 2-aminobenzohydrazide and 4-oxopimelic acid catalyzed by iodine using ionic liquids as green solvents were studied. The results showed that when there was no substituents on N atoms attached to amide group of the hydrazide, it will successfully constructed three new rings and formed pyridazino[6, 1-b]pyrrolo[1, 2-a]quinazoline-1, 6, 9(7H)-trione derivatives. The structure of 2, 3, 4, 5-tetrahydro-1H, 9H-pyridazino[6, 1-b]pyrrolo[1, 2-a]quinazoline-1, 6, 9(7H)-trione (3a) was confirmed by X-ray diffraction analysis. However, when the substituents were aryl groups, the pyridazine ring did not closed as expected due to the steric hindrance, and gave tetrahydropyrrolo[1, 2-a]quinazolin-3a(1H))-propionic acid derivatives. The advantages of this approach were the simplicity of the synthesis route, environmental protection, easy operation and high efficiency.
The reactions between 2-aminobenzohydrazide and 4-oxopimelic acid catalyzed by iodine using ionic liquids as green solvents were studied. The results showed that when there was no substituents on N atoms attached to amide group of the hydrazide, it will successfully constructed three new rings and formed pyridazino[6, 1-b]pyrrolo[1, 2-a]quinazoline-1, 6, 9(7H)-trione derivatives. The structure of 2, 3, 4, 5-tetrahydro-1H, 9H-pyridazino[6, 1-b]pyrrolo[1, 2-a]quinazoline-1, 6, 9(7H)-trione (3a) was confirmed by X-ray diffraction analysis. However, when the substituents were aryl groups, the pyridazine ring did not closed as expected due to the steric hindrance, and gave tetrahydropyrrolo[1, 2-a]quinazolin-3a(1H))-propionic acid derivatives. The advantages of this approach were the simplicity of the synthesis route, environmental protection, easy operation and high efficiency.
2017, 37(12): 3204-3212
doi: 10.6023/cjoc201706002
Abstract:
green synthetic method was constructed for the synthesis of indanone fused pyrrolone compounds, which based on the catalyst-free reaction of N-alkyl-1-methylthio-2-nitroethenamine (1) with ninhydrin hydrate (2) in ethanol at reflux. As a result, a series of indanone fused pyrrolones have been synthesized with 91%~98% yields by this one-step reaction. This protocol possesses some advantages including readily available starting materials, simple operation and concise synthetic route and so on.
green synthetic method was constructed for the synthesis of indanone fused pyrrolone compounds, which based on the catalyst-free reaction of N-alkyl-1-methylthio-2-nitroethenamine (1) with ninhydrin hydrate (2) in ethanol at reflux. As a result, a series of indanone fused pyrrolones have been synthesized with 91%~98% yields by this one-step reaction. This protocol possesses some advantages including readily available starting materials, simple operation and concise synthetic route and so on.
2017, 37(12): 3213-3219
doi: 10.6023/cjoc201707005
Abstract:
An efficient and convenient transition metal-free procedure for the synthesis of 3-sulfenylindoles derivatives in moderate to good yields from readily available indoles and thiols in basic ionic liquid has been developed. Their structures were confirmed by 1H NMR, 13C NMR and HRMS. This sulfenylation process provides a novel route for directly accessing 3-sulfenylindoles in good to excellent yields and good functional group tolerance with high atom efficiency. Notably, the current methodology could also be conveniently applied to the synthesis of thioarylated naturally occurring biologically active frameworks.
An efficient and convenient transition metal-free procedure for the synthesis of 3-sulfenylindoles derivatives in moderate to good yields from readily available indoles and thiols in basic ionic liquid has been developed. Their structures were confirmed by 1H NMR, 13C NMR and HRMS. This sulfenylation process provides a novel route for directly accessing 3-sulfenylindoles in good to excellent yields and good functional group tolerance with high atom efficiency. Notably, the current methodology could also be conveniently applied to the synthesis of thioarylated naturally occurring biologically active frameworks.
2017, 37(12): 3220-3228
doi: 10.6023/cjoc201705023
Abstract:
Iodine-catalyzed Kabachnik-Fields reaction with trialkyl phosphites for the synthesis of α-amino phosphates was developed. This transformation completes rapidly at 40℃, and is well tolerated with a range of amines and phosphites. Moreover, the products afforded by salicyl aldehydes with trialkyl phosphites could efficiently convert to benzoxazines containing phosphate under mild conditions, which provide a new precursor of new phenolic resin
Iodine-catalyzed Kabachnik-Fields reaction with trialkyl phosphites for the synthesis of α-amino phosphates was developed. This transformation completes rapidly at 40℃, and is well tolerated with a range of amines and phosphites. Moreover, the products afforded by salicyl aldehydes with trialkyl phosphites could efficiently convert to benzoxazines containing phosphate under mild conditions, which provide a new precursor of new phenolic resin
2017, 37(12): 3229-3235
doi: 10.6023/cjoc201706012
Abstract:
Poly(ethylene terephthalate-co-isomannide terephthalate-co-ethylene isophthalate-co-isomannide isophthalate) (PEⅡT) was synthesized. The crystallization, optical and thermal performances of PEⅡT were investigated by using differential scanning calorimetry (DSC), ultraviolet-visible-near-infrared spectroscopy (UV-Vis-NIR), X-ray diffraction (XRD) and polarized light microscopy (POM). The results demonstrate that the crystallinity and crystallization rate of PEⅡT can be reduced effectively with the increase of the content of isophthalic acid units in copolyester PEⅡT. The increase of the content of isophthalic acid units made the steric hindrance of PEⅡT molecular chains increase, resulting in the decrease of crystallization ability, which is mainly because its cooling crystallization temperature gradually rise and the melt crystallization temperature gradually decrease until no generation of thermal crystallization phenomenon. Due to the decrease of the crystalline part, the haze of PEⅡT can be completely reduced to zero, and the light transmittance can reach 90.7%. At the same time, it was found that the decrease of PEⅡT light transmittance stems from the increase of yellowing degree, which makes the blue violet light of 330~550 nm wavelength absorbed by PEⅡT, leading to the low light transmittance. The melting point of PEⅡT is greatly affected by the content of isophthalic acid, but it still maintains good thermal decomposition performance.
Poly(ethylene terephthalate-co-isomannide terephthalate-co-ethylene isophthalate-co-isomannide isophthalate) (PEⅡT) was synthesized. The crystallization, optical and thermal performances of PEⅡT were investigated by using differential scanning calorimetry (DSC), ultraviolet-visible-near-infrared spectroscopy (UV-Vis-NIR), X-ray diffraction (XRD) and polarized light microscopy (POM). The results demonstrate that the crystallinity and crystallization rate of PEⅡT can be reduced effectively with the increase of the content of isophthalic acid units in copolyester PEⅡT. The increase of the content of isophthalic acid units made the steric hindrance of PEⅡT molecular chains increase, resulting in the decrease of crystallization ability, which is mainly because its cooling crystallization temperature gradually rise and the melt crystallization temperature gradually decrease until no generation of thermal crystallization phenomenon. Due to the decrease of the crystalline part, the haze of PEⅡT can be completely reduced to zero, and the light transmittance can reach 90.7%. At the same time, it was found that the decrease of PEⅡT light transmittance stems from the increase of yellowing degree, which makes the blue violet light of 330~550 nm wavelength absorbed by PEⅡT, leading to the low light transmittance. The melting point of PEⅡT is greatly affected by the content of isophthalic acid, but it still maintains good thermal decomposition performance.
2017, 37(12): 3236-3241
doi: 10.6023/cjoc201605019
Abstract:
new strategy for sodium carbonate-mediated substitution reaction between 2H-azirines and 1H-benzotriazole is reported. This protocol provides an effective way for construction 2-(benzotriazol-1-yl)-2H-azirines. The advantages of this reaction are mild conditions, metal-free and easy operation.
new strategy for sodium carbonate-mediated substitution reaction between 2H-azirines and 1H-benzotriazole is reported. This protocol provides an effective way for construction 2-(benzotriazol-1-yl)-2H-azirines. The advantages of this reaction are mild conditions, metal-free and easy operation.
2017, 37(12): 3186-3190
doi: 10.6023/cjoc201705017
Abstract:
The oxidative bromination of anilines was realized with ZnAl-BrO3--LDHs/KBr as the bromine source at ambient temperature in acidic medium (AcOH/H2O). High yields of monobrominated or polybrominated anilines were achieved for a wide range of anilines. Both the substrate structure and the reaction conditions will significantly influence the reaction selectivity. The use of inexpensive reagents, environmentally benign and operationally simple process, and excellent yields make it a good alternative to the synthesis of bromoanilines.
The oxidative bromination of anilines was realized with ZnAl-BrO3--LDHs/KBr as the bromine source at ambient temperature in acidic medium (AcOH/H2O). High yields of monobrominated or polybrominated anilines were achieved for a wide range of anilines. Both the substrate structure and the reaction conditions will significantly influence the reaction selectivity. The use of inexpensive reagents, environmentally benign and operationally simple process, and excellent yields make it a good alternative to the synthesis of bromoanilines.
2017, 37(12): 3198-3203
doi: 10.6023/cjoc201705041
Abstract:
A simple and efficient selective halogenation (Cl, Br) reaction in the C5 position of 8-amidoquinolines has been developed via catalyst free C-H bond elaboration. This facile synthetic method shows good substrate tolerance and most of the halogenated products were obtained with excellent yield.
A simple and efficient selective halogenation (Cl, Br) reaction in the C5 position of 8-amidoquinolines has been developed via catalyst free C-H bond elaboration. This facile synthetic method shows good substrate tolerance and most of the halogenated products were obtained with excellent yield.
2017, 37(12): 3242-3247
doi: 10.6023/cjoc201711015
Abstract:
Since benzimidazole containing moieties have a lot of pharmacological activities, we reported the ageneral metal-free and cost-effective, I2/DTBP-catalyzed method for the functionalization of N-H bonds of azoles via α-C(sp3)-H activation of cyclic ethers or cyclic thioethers. And this method is also applicable to a diverse range of N-substituted azoles and cyclic ethers/thioethers. By using the free-radical scavenger 2, 2, 6, 6-tetramethylpiperidin-1-oxyl (TEMPO) as a control, we suggest that a radical/SET mechanism proceeding via a radical/oxonium or thionium ion may be involved in the reaction.
Since benzimidazole containing moieties have a lot of pharmacological activities, we reported the ageneral metal-free and cost-effective, I2/DTBP-catalyzed method for the functionalization of N-H bonds of azoles via α-C(sp3)-H activation of cyclic ethers or cyclic thioethers. And this method is also applicable to a diverse range of N-substituted azoles and cyclic ethers/thioethers. By using the free-radical scavenger 2, 2, 6, 6-tetramethylpiperidin-1-oxyl (TEMPO) as a control, we suggest that a radical/SET mechanism proceeding via a radical/oxonium or thionium ion may be involved in the reaction.
2017, 37(12): 3248-3256
doi: 10.6023/cjoc201710037
Abstract:
An amphiphilic triblock copolymer comprising double-bond-containing poly(phenoxyallene) (PPOA) was synthesized by a combination of conventional free radical polymerization and atom transfer radical polymerization (ATRP) via the site transformation strategy. A new bifunctional initiator containing azo and ATRP initiating groups was prepared and used for conventional free radical homopolymerization of phenoxyallene (POA) to afford a PPOA-based macroinitiator bearing ATRP initiating groups. Subsequent ATRP of hydrophilic monomer, 2-((diethylamino)ethyl methacrylate) (DEAEMA), initiated by PPOA-based macroinitiator afforded PDEAEMA-b-PPOA-b-PDEAEMA triblock copolymer. This triblock copolymer can self-assemble into micelles, and critical micelle concentration (cmc) of PDEAEMA-b-PPOA-b-PDEAEMA amphiphilic triblock copolymer in aqueous solution was determined by fluorescence probe technique. The dependence of cmc on pH and ion strength was also investigated.
An amphiphilic triblock copolymer comprising double-bond-containing poly(phenoxyallene) (PPOA) was synthesized by a combination of conventional free radical polymerization and atom transfer radical polymerization (ATRP) via the site transformation strategy. A new bifunctional initiator containing azo and ATRP initiating groups was prepared and used for conventional free radical homopolymerization of phenoxyallene (POA) to afford a PPOA-based macroinitiator bearing ATRP initiating groups. Subsequent ATRP of hydrophilic monomer, 2-((diethylamino)ethyl methacrylate) (DEAEMA), initiated by PPOA-based macroinitiator afforded PDEAEMA-b-PPOA-b-PDEAEMA triblock copolymer. This triblock copolymer can self-assemble into micelles, and critical micelle concentration (cmc) of PDEAEMA-b-PPOA-b-PDEAEMA amphiphilic triblock copolymer in aqueous solution was determined by fluorescence probe technique. The dependence of cmc on pH and ion strength was also investigated.
2017, 37(12): 3257-3261
doi: 10.6023/cjoc201709043
Abstract:
2-Amino-3, 1-benzothiazine and its functionalized derivatives are known as useful compounds with a range of biological applications. A highly efficient reaction of o-aminocinnamate and isothiocyanates catalyzed by cationic ytterbium complex[Yb(CH3CN)9]3+[(AlCl4)3]3-·CH3CN under mild and solvent-free conditions was developed, which provides 2-amino-3, 1-benzothiazines in high yields and chemoselectivity.
2-Amino-3, 1-benzothiazine and its functionalized derivatives are known as useful compounds with a range of biological applications. A highly efficient reaction of o-aminocinnamate and isothiocyanates catalyzed by cationic ytterbium complex[Yb(CH3CN)9]3+[(AlCl4)3]3-·CH3CN under mild and solvent-free conditions was developed, which provides 2-amino-3, 1-benzothiazines in high yields and chemoselectivity.
2017, 37(12): 3262-3266
doi: 10.6023/cjoc201708007
Abstract:
Micromonospora sp. TP-A0468 harbors multiple biosynthetic gene clusters encoding the biosynthesis of secondary metabolites, including kosinostatin (KST) and rifamycins. In our study on the biosynthesis of KST, a new anthracycline polyketide 554B was isolated from the kstB1 deletion mutant ∆kstB1 and identified as shunt product of KST pathway bearing 4-acetyl-2, 3, 6-deoxyhexosyl moiety. The unexpected elimination of C-3' hydroxyl suggests a 3, 4-dehydratase involved in the biosynthesis of 554B, of which the encoding gene was proposed to located beyond the kst gene cluster. Bioinformatic analysis revealed orf6 of rifamycin biosynthetic gene cluster (rif) was the candidate of required 3, 4-dehydratase gene. Deletion of orf6 abolished the production of 554B, confirming the involvement of orf6 in the biosynthesis of 554B. Our study attributed orf6 to the origin of 2, 3, 6-deoxyhexosyl and unveiled the cooperation between biosynthetic gene clusters in Micromonospora sp. TP-A0468.
Micromonospora sp. TP-A0468 harbors multiple biosynthetic gene clusters encoding the biosynthesis of secondary metabolites, including kosinostatin (KST) and rifamycins. In our study on the biosynthesis of KST, a new anthracycline polyketide 554B was isolated from the kstB1 deletion mutant ∆kstB1 and identified as shunt product of KST pathway bearing 4-acetyl-2, 3, 6-deoxyhexosyl moiety. The unexpected elimination of C-3' hydroxyl suggests a 3, 4-dehydratase involved in the biosynthesis of 554B, of which the encoding gene was proposed to located beyond the kst gene cluster. Bioinformatic analysis revealed orf6 of rifamycin biosynthetic gene cluster (rif) was the candidate of required 3, 4-dehydratase gene. Deletion of orf6 abolished the production of 554B, confirming the involvement of orf6 in the biosynthesis of 554B. Our study attributed orf6 to the origin of 2, 3, 6-deoxyhexosyl and unveiled the cooperation between biosynthetic gene clusters in Micromonospora sp. TP-A0468.
2017, 37(12): 3267-3273
doi: 10.6023/cjoc201708026
Abstract:
In order to explore novel pyrazole oxime derivatives with potent biological activities, a series of novel pyrazole oximes carrying tetrazole unit were designed and synthesized by the method of active substructure combination. The structures of the title compounds were confirmed by 1H NMR, 13C NMR, and elemental analysis. Preliminary bioassay data showed that some aimed compounds displayed good insecticidal activities. At the concentration of 500 μg/mL, ten compounds exhibited insecticidal activity against Oriental armyworm with 90%~100%, nine compounds had insecticidal activity against Aphis medicaginis with 80%~100%, ten compounds possessed insecticidal activity against Nilaparvata lugens with 80%~100%, and one compound exhibited 80% acaricidal activity against Tetranychus cinnabarinus. When the concentration was reduced to 100 μg/mL, one compound still showed insecticidal activity against Aphis medicaginis with 85%. Additionally, some compounds had certain fungicidal activity, at 200 μg/mL two compounds showed 60%~80% fungicidal activity against Pseudoperonospora cubensis.
In order to explore novel pyrazole oxime derivatives with potent biological activities, a series of novel pyrazole oximes carrying tetrazole unit were designed and synthesized by the method of active substructure combination. The structures of the title compounds were confirmed by 1H NMR, 13C NMR, and elemental analysis. Preliminary bioassay data showed that some aimed compounds displayed good insecticidal activities. At the concentration of 500 μg/mL, ten compounds exhibited insecticidal activity against Oriental armyworm with 90%~100%, nine compounds had insecticidal activity against Aphis medicaginis with 80%~100%, ten compounds possessed insecticidal activity against Nilaparvata lugens with 80%~100%, and one compound exhibited 80% acaricidal activity against Tetranychus cinnabarinus. When the concentration was reduced to 100 μg/mL, one compound still showed insecticidal activity against Aphis medicaginis with 85%. Additionally, some compounds had certain fungicidal activity, at 200 μg/mL two compounds showed 60%~80% fungicidal activity against Pseudoperonospora cubensis.
2017, 37(12): 3274-3281
doi: 10.6023/cjoc201706037
Abstract:
A novel tetraphenylethyene-functionalized rhodamine derivative (TPE-RhB) was designed and synthesized. FT-IR, NMR, MS, elemental analysis, cyclic voltammetry electrochemical analysis, UV-Vis, and molecular fluorescence were used to study its structure, electrochemical and optical properties. These results showed that the electron affinity of TPE-RhB was 3.66 eV, which is expected to develop electron-transporting material. A significant aggregation-induced emission (AIE) effect of TPE-RhB was found through solution fluorescence test in different V(EtOH):V(H2O) mixed solvents. Furthermore, sensor TPE-RhB displayed highly seletive and sensitive off-on fluorescence response and naked-eye color change to Fe3+ in EtOH/H2O (V:V=1:1, Tris-HCl pH 7.0) solution. The association constant between TPE-RhB and Fe3+ was detected to be 3.12×103 and the detection limit was calculated to be 3.53×10-7 mol·L-1. The probe TPE-RhB also showed a good linearity (R2=0.9915) in the range of 60~180 μmol/L of Fe3+ ion. The mechanisms had been supported by Job's plot evalution, fluorescence titrations, and 1H NMR spectroscopic studies.
A novel tetraphenylethyene-functionalized rhodamine derivative (TPE-RhB) was designed and synthesized. FT-IR, NMR, MS, elemental analysis, cyclic voltammetry electrochemical analysis, UV-Vis, and molecular fluorescence were used to study its structure, electrochemical and optical properties. These results showed that the electron affinity of TPE-RhB was 3.66 eV, which is expected to develop electron-transporting material. A significant aggregation-induced emission (AIE) effect of TPE-RhB was found through solution fluorescence test in different V(EtOH):V(H2O) mixed solvents. Furthermore, sensor TPE-RhB displayed highly seletive and sensitive off-on fluorescence response and naked-eye color change to Fe3+ in EtOH/H2O (V:V=1:1, Tris-HCl pH 7.0) solution. The association constant between TPE-RhB and Fe3+ was detected to be 3.12×103 and the detection limit was calculated to be 3.53×10-7 mol·L-1. The probe TPE-RhB also showed a good linearity (R2=0.9915) in the range of 60~180 μmol/L of Fe3+ ion. The mechanisms had been supported by Job's plot evalution, fluorescence titrations, and 1H NMR spectroscopic studies.
2017, 37(12): 3282-3288
doi: 10.6023/cjoc201707001
Abstract:
Twelve novel isoxazoles containing (1-bi(4-fluorophenyl)methyl)piperazine unit were prepared in two steps starting from propargyl bromide, (1-bi(4-fluorophenyl)methyl)piperazine and hydroxymoyl chlorides with moderate yield (21%~76%). The structures of the new compounds were characterized by IR, MS, 1H NMR, 13C NMR and elemental analysis, and their in vitro anti-tumor activity was screened. The bioactive assay for the newly prepared compounds manifested that ten newly isoxazole derivatives exhibited good to excellent inhibitory activity against CDC25B in 20 μg/mL with inhibition of 64.15%~95.87% and IC50 of 35.62~13.67 μg/mL. Four isoxazoles exhibited good to excellent inhibitory activity against Leukemia cell HL-60 in 40 μmol/L (IC50:36.51~15.25 μg/mL), 2-(2-fluorophenyl)-5-(1-(bi-(4-fluorophenyl)methyl)-piperazine)methylisoxazole (5g) and 2-(4-fluorophenyl)-5-(1-(bi-(4-fluorophenyl)methyl)piperazine)methylisoxazole (5h) exhibited good to excellent inhibitory activity against Lung cancer cell A-549 (IC50 value up to 21.09 and 35.36 μg/mL, respectively).
Twelve novel isoxazoles containing (1-bi(4-fluorophenyl)methyl)piperazine unit were prepared in two steps starting from propargyl bromide, (1-bi(4-fluorophenyl)methyl)piperazine and hydroxymoyl chlorides with moderate yield (21%~76%). The structures of the new compounds were characterized by IR, MS, 1H NMR, 13C NMR and elemental analysis, and their in vitro anti-tumor activity was screened. The bioactive assay for the newly prepared compounds manifested that ten newly isoxazole derivatives exhibited good to excellent inhibitory activity against CDC25B in 20 μg/mL with inhibition of 64.15%~95.87% and IC50 of 35.62~13.67 μg/mL. Four isoxazoles exhibited good to excellent inhibitory activity against Leukemia cell HL-60 in 40 μmol/L (IC50:36.51~15.25 μg/mL), 2-(2-fluorophenyl)-5-(1-(bi-(4-fluorophenyl)methyl)-piperazine)methylisoxazole (5g) and 2-(4-fluorophenyl)-5-(1-(bi-(4-fluorophenyl)methyl)piperazine)methylisoxazole (5h) exhibited good to excellent inhibitory activity against Lung cancer cell A-549 (IC50 value up to 21.09 and 35.36 μg/mL, respectively).
2017, 37(12): 3289-3295
doi: 10.6023/cjoc201707024
Abstract:
In order to explore novel pyrazole derivatives with good biological activities, a series of pyrazole-containing pyrazole oxime esters were designed and synthesized according to the method of active substructure combination. Their structures were determined by 1H NMR, 13C NMR spectra and elemental analysis. The preliminary bioactivity test showed that some of the target compounds had good insecticidal activity against Aphis medicaginis at a concentration of 500 μg/mL, some title compounds displayed good insecticidal activity against Nilaparvata lugens at 500 μg/mL. In addition, some of the designed compounds exhibited certain anti-tumor activity against HepG2 cells.
In order to explore novel pyrazole derivatives with good biological activities, a series of pyrazole-containing pyrazole oxime esters were designed and synthesized according to the method of active substructure combination. Their structures were determined by 1H NMR, 13C NMR spectra and elemental analysis. The preliminary bioactivity test showed that some of the target compounds had good insecticidal activity against Aphis medicaginis at a concentration of 500 μg/mL, some title compounds displayed good insecticidal activity against Nilaparvata lugens at 500 μg/mL. In addition, some of the designed compounds exhibited certain anti-tumor activity against HepG2 cells.
