An efficient synthesis of chiral benzannulated spiroketals via catalytic asymmetric[3+2]cycloaddition of exocyclic enol ethers with p-quinones was achieved.The transformation was enabled by a chiral N,N′-dioxides/Tm^...An efficient synthesis of chiral benzannulated spiroketals via catalytic asymmetric[3+2]cycloaddition of exocyclic enol ethers with p-quinones was achieved.The transformation was enabled by a chiral N,N′-dioxides/Tm^(Ⅲ)complex as the Lewis acid catalyst and afforded a series of enantiomerically enriched benzannulated spiroketal derivatives in good yields(up to 99%)and enantioselectivities(up to 98%ee).Topographic steric maps and distribution of the buried volumes of the catalysts via Cavallo’s SambVca 2 tool were used to elucidate the enantioinduction raised by the ligands and the metal ions.展开更多
Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different ty...Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different types of cyclohexa- 1,4-dione derivatives. The structure of the prepared polymers was confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers show a large amount of nitrogen adsorbed at low relative pressure indicating microporosity. These polymers have Brunauer Emmitt and Teller （BET） surface areas in the range from 492 （m^2g^-1） to 685 （m^2 g^-1）. The prepared polymers were found to be useful for pervaporation separation of methanol-toluene mixture with a separation factor up to 12.5 and fluxes, varying between 6.7×10-3 kg/（m^2 h） and 13.4 × 10^-3 kg/（m^2 h）.展开更多
The stereoselective synthesis of substituted [2,2,1]-bicyclo- heptan-2-one 12,a supposed intermediate to the spiroketal fragment of azadi- rachtin was described.When 12 was treated with mCPBA in CH_2Cl_2 in the pres- ...The stereoselective synthesis of substituted [2,2,1]-bicyclo- heptan-2-one 12,a supposed intermediate to the spiroketal fragment of azadi- rachtin was described.When 12 was treated with mCPBA in CH_2Cl_2 in the pres- ence of excess amount of solid sodium bicarbonate,only 13 was obtained.The spiroketal intermediate 20 was converted from 9 through 5 steps by an alterna- tive route.展开更多
Several simple analogues of peroxyplakoric acid were synthesized by using Kobayashi＇s method to construct the key 1,2-dioxane core and tested in vitro for antimalarial activity. The scope and limitation of the method...Several simple analogues of peroxyplakoric acid were synthesized by using Kobayashi＇s method to construct the key 1,2-dioxane core and tested in vitro for antimalarial activity. The scope and limitation of the method was also briefly examined.展开更多
11 pyrazolyl or pyridinyl substituted tonghaosu analogs were synthesized. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against larvae ...11 pyrazolyl or pyridinyl substituted tonghaosu analogs were synthesized. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against larvae of large white butterfly （Pieris brassicae L.）, larvicidal activity toward mosquito （Culex quinquefasciatus Say） and growth control activity toward larvae of Spodoptera litura Fab were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.展开更多
The spiro concept for chiral ligand design represents an important contribution to the area of asymmetric catalysis. Due to the considerable difficulties in the construction of enantiopure all-carbon spiro backbones, ...The spiro concept for chiral ligand design represents an important contribution to the area of asymmetric catalysis. Due to the considerable difficulties in the construction of enantiopure all-carbon spiro backbones, the development of catalytic asymmetric synthesis of chiral spiro structures via short steps is highly valuable. Herein we present our studies on the catalytic asymmetric synthesis of aromatic spiroketals and the corresponding diphos- phine （SKP） ligands.展开更多
Twenty-one tonghaosu analogs were synthesized via hydroamination or selective reduction of the endocyclic double bond of the corresponding dienol spiroketals. Structures of all the new compounds were confirmed by ^1H ...Twenty-one tonghaosu analogs were synthesized via hydroamination or selective reduction of the endocyclic double bond of the corresponding dienol spiroketals. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against large white butterfly （Pieris brassicae L） and larvicidal activity toward mosquito （Culex quinquefasciatus Say） were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.展开更多
Natural occurring aromatic polyketides from actinomycetes indicate a structurally and functionally diverse fam-ily of polycyclic polyphenols.Some of them are consequently suggested as lead structures for drug developm...Natural occurring aromatic polyketides from actinomycetes indicate a structurally and functionally diverse fam-ily of polycyclic polyphenols.Some of them are consequently suggested as lead structures for drug development.Among them,rubromycins are derived from a single C26 polyketide chain and exhibit an unusual bisbenzannu-lated[5,6]-spiroketal system that connects a highly oxygenated naphthazarin motif to an isocoumarin unit.This type of biosynthetically elusive polycyclic polyketides has shown promising pharmacological activities,includ-ing antimicrobial,anticancer,and enzyme inhibition activity.The unique structures,intriguing biosynthesis,and marked bioactivities of rubromycins have drawn considerable attention from several chemists and biologists.This review covers the isolation,characterization,biosynthesis,and biological studies of these structurally diverse and complex rubromycins.展开更多
A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insectic...A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal ac-tivity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.展开更多
A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this ...A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this mild reaction condition.Furthermore,a hypothetical mechanism is also shown.展开更多
The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ...The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ac-tive component, B-ring-homo-tonghaosu, 2-(2',4'-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Further-more new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its struc-ture and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.展开更多
基金the National Natural Science Foundation of China(Nos.21890723 and 21921002)the Science and Technology Department of Sichuan Province(Nos.2021YJ0561)for financial support.
文摘An efficient synthesis of chiral benzannulated spiroketals via catalytic asymmetric[3+2]cycloaddition of exocyclic enol ethers with p-quinones was achieved.The transformation was enabled by a chiral N,N′-dioxides/Tm^(Ⅲ)complex as the Lewis acid catalyst and afforded a series of enantiomerically enriched benzannulated spiroketal derivatives in good yields(up to 99%)and enantioselectivities(up to 98%ee).Topographic steric maps and distribution of the buried volumes of the catalysts via Cavallo’s SambVca 2 tool were used to elucidate the enantioinduction raised by the ligands and the metal ions.
文摘Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different types of cyclohexa- 1,4-dione derivatives. The structure of the prepared polymers was confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers show a large amount of nitrogen adsorbed at low relative pressure indicating microporosity. These polymers have Brunauer Emmitt and Teller （BET） surface areas in the range from 492 （m^2g^-1） to 685 （m^2 g^-1）. The prepared polymers were found to be useful for pervaporation separation of methanol-toluene mixture with a separation factor up to 12.5 and fluxes, varying between 6.7×10-3 kg/（m^2 h） and 13.4 × 10^-3 kg/（m^2 h）.
文摘The stereoselective synthesis of substituted [2,2,1]-bicyclo- heptan-2-one 12,a supposed intermediate to the spiroketal fragment of azadi- rachtin was described.When 12 was treated with mCPBA in CH_2Cl_2 in the pres- ence of excess amount of solid sodium bicarbonate,only 13 was obtained.The spiroketal intermediate 20 was converted from 9 through 5 steps by an alterna- tive route.
基金Project supported by the National Natural Science Foundation of China （Nos. 20025207, 20272071, 20372075, 20321202）, the Chinese Academy ot Sciences （“Knowledge Innovation”project, KGCX2-SW-209）, and the Major State Basic Research Development Program （No. G2000077502） of China.
文摘Several simple analogues of peroxyplakoric acid were synthesized by using Kobayashi＇s method to construct the key 1,2-dioxane core and tested in vitro for antimalarial activity. The scope and limitation of the method was also briefly examined.
文摘11 pyrazolyl or pyridinyl substituted tonghaosu analogs were synthesized. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against larvae of large white butterfly （Pieris brassicae L.）, larvicidal activity toward mosquito （Culex quinquefasciatus Say） and growth control activity toward larvae of Spodoptera litura Fab were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.
文摘The spiro concept for chiral ligand design represents an important contribution to the area of asymmetric catalysis. Due to the considerable difficulties in the construction of enantiopure all-carbon spiro backbones, the development of catalytic asymmetric synthesis of chiral spiro structures via short steps is highly valuable. Herein we present our studies on the catalytic asymmetric synthesis of aromatic spiroketals and the corresponding diphos- phine （SKP） ligands.
基金Project supported by the National Natural Science Foundation of China （Nos. 29672083, 20072043）, the Chinese Academy of Sciences, the Ministry of Science and Technology of China （No. G2000077502）, and the Shanghai Commission of Science and Technology.
文摘Twenty-one tonghaosu analogs were synthesized via hydroamination or selective reduction of the endocyclic double bond of the corresponding dienol spiroketals. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against large white butterfly （Pieris brassicae L） and larvicidal activity toward mosquito （Culex quinquefasciatus Say） were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.
基金This work was financially supported by the National Natural Science Foundation of China(No.81903494)the Scientific Research Foun-dation of Qingdao University.
文摘Natural occurring aromatic polyketides from actinomycetes indicate a structurally and functionally diverse fam-ily of polycyclic polyphenols.Some of them are consequently suggested as lead structures for drug development.Among them,rubromycins are derived from a single C26 polyketide chain and exhibit an unusual bisbenzannu-lated[5,6]-spiroketal system that connects a highly oxygenated naphthazarin motif to an isocoumarin unit.This type of biosynthetically elusive polycyclic polyketides has shown promising pharmacological activities,includ-ing antimicrobial,anticancer,and enzyme inhibition activity.The unique structures,intriguing biosynthesis,and marked bioactivities of rubromycins have drawn considerable attention from several chemists and biologists.This review covers the isolation,characterization,biosynthesis,and biological studies of these structurally diverse and complex rubromycins.
基金the National Natural Science Foundation of China (Nos. 29672083, 20072043), the Chinese Academy of Sciences, the State Ministry of Science and Technology (No. 2000077502), the Shanghai Committee of Science and Technology.
文摘A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal ac-tivity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.
基金support from the Natural Science Foundation of China(Nos.29070070,29372077).
文摘A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this mild reaction condition.Furthermore,a hypothetical mechanism is also shown.
基金the National Natural Science Foundation of China (Grant Nos. 29672083, 20072043), Chinese Academy of Sciences, the State Ministry of Science and Technology (No. G2000077502), Shanghai Committee of Science and Technology and the
文摘The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ac-tive component, B-ring-homo-tonghaosu, 2-(2',4'-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Further-more new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its struc-ture and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.
