Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridi...Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridine, followed by ring-closure with sodium sulfide or primary amine to form the oxy-bridged bicyclic molecules in good yields. Results Two bicyclic azasugars and a thiosugar were produced from L-sorbose in several steps. Conclusion The described procedures provide an efficient method to synthesize bicyclic azasugar and thiosugar with novel scaffold as potential glycosidase inhibitors.展开更多
In this paper,we report the concise total syntheses of three botryane sesquiterpenoids:dehydrobotrydienal,dehydrobotrydienol,and 10-oxodehydrodihydrobotrydial.The key transformations include tandem Co-tetramethylthiou...In this paper,we report the concise total syntheses of three botryane sesquiterpenoids:dehydrobotrydienal,dehydrobotrydienol,and 10-oxodehydrodihydrobotrydial.The key transformations include tandem Co-tetramethylthiourea-catalyzed Pauson–Khand and 6π-electrocyclization reactions to forge the tricyclic core structure of the botryanes,and further oxidative aromatization and oxidation to complete the total syntheses.展开更多
One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = ...One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = 5.5274（11）, b = 8.1603（16）, c = 28.830（6） A, V = 1300.4（4） A^3, Z = 4, Mr= 276.28, Dc = 1.411 g/cm^3, F（000） = 576,μ = 0.360 mm^-1, R = 0.0259 and wR = 0.0652 for 1414 observed reflections with I 〉 2σ（I）. While compound 2, C14H17N2O2PS, was obtained as a ring-cleavage product of compound 1. This crystal is of monoclinic system, space group P21/c with a = 9.5619（19）, b = 21.879（4）, c = 7.3618（15） A, β= 103.03（3）°, V=1500.4（5） A^3, Z = 4, Mr= 308.33, Dc = 1.365 g/cm^3, F（000） = 648,μ = 0.325 mm^-1, R = 0.0383 and wR =0.0742 for 2283 observed reflections with I 〉 2σ（I）. Phosphorus atom in each compound bonds with sulfur and carbon atoms using sp^3 hybrid orbitals, and crystals of these two compounds are formed and stabilized by intermolecular hydrogen bonds and Van der Waals＇ forces. The special structure of compound 1 leads to its good antimicrobial activity against staphylococcus aureus.展开更多
We reported a new protocol for constructing a unique indolizine-containing perifused tricycle by combining a copper relay-catalyzed three-component cascade with a 12πelectrocyclization reaction from readily available...We reported a new protocol for constructing a unique indolizine-containing perifused tricycle by combining a copper relay-catalyzed three-component cascade with a 12πelectrocyclization reaction from readily available starting materials.The indolizine generated by the copper-catalyzed multicomponent cascade is a key intermediate obtained during subsequent spontaneous electrocyclization.In contrast to the traditional SEAr reaction model,this study is based on the tetraene-like character of indolizine to form an aromatic heterocycle 12πelectron system that can spontaneously trigger 12πelectrocyclization.This transformation can not only enhance the reactivity of indolizine but also improve the electrocyclization model.This convergent strategy can significantly enhance synthetic versatility,and the resulting perifused cycle products containing indolizine may serve as a molecular platform for the discovery and characterization of pharmaceuticals and functional molecules.展开更多
As an important part of pericyclic reaction,6π 1,5-electrocyclization plays an important role in organic synthesis and chemical theory.Many types of five-membered rings could be constructed via 1,5-electrocyclization...As an important part of pericyclic reaction,6π 1,5-electrocyclization plays an important role in organic synthesis and chemical theory.Many types of five-membered rings could be constructed via 1,5-electrocyclization with high atom economy.Some elegant works have been reported in this field in the past few decades.However,it still needs a lot of effort in further advancements of 1,5-electrocyclization.展开更多
Comprehensive Summary.Herein, an intermolecular palladium(II)-catalyzed regioselective [4+2] benzannulation reaction capable of converting 2-pyridones into quinolinones was developed using electron-deficient alkenes a...Comprehensive Summary.Herein, an intermolecular palladium(II)-catalyzed regioselective [4+2] benzannulation reaction capable of converting 2-pyridones into quinolinones was developed using electron-deficient alkenes as two-carbon units. An examination of the reaction mechanism indicated that the extension from 2-pyridone to quinolinone was likely facilitated through a series of sequential C—H activation reactions or 6π electrocyclization, culminating in dehydrogenative aromatization. This method of diversity-oriented synthesis of quinolinone derivatives is characterized by a broad substrate scope, atom economy, and excellent chemical selectivity. In addition, these quinolinone derivatives exhibit fluorescent absorption within the visible-light spectrum, which makes them suitable candidates for the development of innovative fluorescent probes.展开更多
基金We thank the National Science Foundation of China(NSFC,N0.20372003)for financial support.
文摘Aim To develop a concise method for the synthesis of bicyclic azasugar and thiosugar with novel scaffold. Methods The two primary hydroxyl groups of compound 1 were selectively protected with tosyl cloloride in pyridine, followed by ring-closure with sodium sulfide or primary amine to form the oxy-bridged bicyclic molecules in good yields. Results Two bicyclic azasugars and a thiosugar were produced from L-sorbose in several steps. Conclusion The described procedures provide an efficient method to synthesize bicyclic azasugar and thiosugar with novel scaffold as potential glycosidase inhibitors.
基金supported by the National Natural Science Foundation of China (Nos. 21772008, 21632002 and U1606403)Natural Science Foundation of Guangdong Province (No. 2016A030306011)+1 种基金Shenzhen Basic Research Program (Nos. JCYJ20170818090044432 and JCYJ20160226105337556)Qingdao National Laboratory for Marine Science and Technology (No. LMDBKF201703)
文摘In this paper,we report the concise total syntheses of three botryane sesquiterpenoids:dehydrobotrydienal,dehydrobotrydienol,and 10-oxodehydrodihydrobotrydial.The key transformations include tandem Co-tetramethylthiourea-catalyzed Pauson–Khand and 6π-electrocyclization reactions to forge the tricyclic core structure of the botryanes,and further oxidative aromatization and oxidation to complete the total syntheses.
基金This work was supported by the National Natural Science Foundation of China (20271046), Natural Science Foundation of Henan Education Department (2004150004) and Natural Foundation of Henan Province (200011500027)
文摘One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = 5.5274（11）, b = 8.1603（16）, c = 28.830（6） A, V = 1300.4（4） A^3, Z = 4, Mr= 276.28, Dc = 1.411 g/cm^3, F（000） = 576,μ = 0.360 mm^-1, R = 0.0259 and wR = 0.0652 for 1414 observed reflections with I 〉 2σ（I）. While compound 2, C14H17N2O2PS, was obtained as a ring-cleavage product of compound 1. This crystal is of monoclinic system, space group P21/c with a = 9.5619（19）, b = 21.879（4）, c = 7.3618（15） A, β= 103.03（3）°, V=1500.4（5） A^3, Z = 4, Mr= 308.33, Dc = 1.365 g/cm^3, F（000） = 648,μ = 0.325 mm^-1, R = 0.0383 and wR =0.0742 for 2283 observed reflections with I 〉 2σ（I）. Phosphorus atom in each compound bonds with sulfur and carbon atoms using sp^3 hybrid orbitals, and crystals of these two compounds are formed and stabilized by intermolecular hydrogen bonds and Van der Waals＇ forces. The special structure of compound 1 leads to its good antimicrobial activity against staphylococcus aureus.
基金The authors thank NSFC(grant nos.21772019 and 22371024)support from the Venture&Innovation Support Program for Chongqing Overseas Returnees(grant nos.cx2019007 and cx2020047)the Basic and Frontier Research Project of Chongqing(grant no.CSTB2022NSCQ-MSX0320).
文摘We reported a new protocol for constructing a unique indolizine-containing perifused tricycle by combining a copper relay-catalyzed three-component cascade with a 12πelectrocyclization reaction from readily available starting materials.The indolizine generated by the copper-catalyzed multicomponent cascade is a key intermediate obtained during subsequent spontaneous electrocyclization.In contrast to the traditional SEAr reaction model,this study is based on the tetraene-like character of indolizine to form an aromatic heterocycle 12πelectron system that can spontaneously trigger 12πelectrocyclization.This transformation can not only enhance the reactivity of indolizine but also improve the electrocyclization model.This convergent strategy can significantly enhance synthetic versatility,and the resulting perifused cycle products containing indolizine may serve as a molecular platform for the discovery and characterization of pharmaceuticals and functional molecules.
基金This work was supported by the National Natural Science Foundation of China(Nos.21725201,21890721 and 22131001)。
文摘As an important part of pericyclic reaction,6π 1,5-electrocyclization plays an important role in organic synthesis and chemical theory.Many types of five-membered rings could be constructed via 1,5-electrocyclization with high atom economy.Some elegant works have been reported in this field in the past few decades.However,it still needs a lot of effort in further advancements of 1,5-electrocyclization.
基金the Natural Science Foundation of Anhui University of Chinese Medicine(2021rczd003 and 2022AH050440)the Cooperation Project of Fuyang Municipal Government and Fuyang Normal University(No.SXHZ202002)+1 种基金the Natural Science Foundation of Fuyang Normal University(FYKFKT24001)the National Natural Science Foundation of China(Grant No.22301074)for financial support.
文摘Comprehensive Summary.Herein, an intermolecular palladium(II)-catalyzed regioselective [4+2] benzannulation reaction capable of converting 2-pyridones into quinolinones was developed using electron-deficient alkenes as two-carbon units. An examination of the reaction mechanism indicated that the extension from 2-pyridone to quinolinone was likely facilitated through a series of sequential C—H activation reactions or 6π electrocyclization, culminating in dehydrogenative aromatization. This method of diversity-oriented synthesis of quinolinone derivatives is characterized by a broad substrate scope, atom economy, and excellent chemical selectivity. In addition, these quinolinone derivatives exhibit fluorescent absorption within the visible-light spectrum, which makes them suitable candidates for the development of innovative fluorescent probes.
