A series of dearomatized isoprenylated acylphloroglucinols derivatives,hyperhenols A-E(1-5),as well as seven known analogues(6-12),were characterized from Hypericum henryi.Their structures were determined by combinati...A series of dearomatized isoprenylated acylphloroglucinols derivatives,hyperhenols A-E(1-5),as well as seven known analogues(6-12),were characterized from Hypericum henryi.Their structures were determined by combination of NMR,ECD spectroscopy,and X-ray difraction analysis.Compounds 1 and 6-8 were tested to exhibit potential antitumor properties,of which 6 and 7 inhibited cell growth through inducing apoptosis and cell cycle arrest.In addition,these compounds could induce autophagy and PINK1/Parkin-mediated mitophagy in cancer cell lines,as well as suppress lung cancer A549 cells metastasis in vitro.展开更多
Herein,we disclose a highly regio-/chemoselective tandem asymmetric dearomatized halofunctionalization reaction of phenoltethered ynamides with diverse electrophilic halogenation sources in a catalyst-free manner for ...Herein,we disclose a highly regio-/chemoselective tandem asymmetric dearomatized halofunctionalization reaction of phenoltethered ynamides with diverse electrophilic halogenation sources in a catalyst-free manner for the practical and rapid assembly of a series of halogenated spirocyclic enones.Besides,the related dearomatized selenation and protonation are also achieved,affording the corresponding selenated and protonated spirocycles in high efficiency.Moreover,the enantioselectivities of these products can be perfectly induced by Evans auxiliaries(99%ees).Significantly,this protocol not only represents the first tandem asymmetric halofunctionalization reaction of phenol derivatives,but also constitutes the first asymmetric halogenation/selenation of ynamides.Theoretical calculations indicate a remote induction model of Evans chiral auxiliary-attached keteniminium.展开更多
P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process o...P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process of aromatic hydroxylation and mechanism of regioselectivity catalyzed by cytochrome P450 monooxygenases remained ambiguous.Here,we have resolved these issues.With a stable chiral organofluorine probe,and especially with X-ray data of two isolated arene oxides derivatives,we demonstrate that an arene oxide pathway is definitely involved in P450-catalyzed aromatic hydroxylation.By the capture,isolation,identification and reactivity exploration of the arene 1,2-oxide and arene 2,3-oxide intermediates,together with advanced QM calculations,the mechanism of how two intermediates go to the same product has been elucidated.In addition to the model substrate,we also confirmed that an arene oxide intermediate is involved in the P450-catalyzed hydroxylation pathway of a natural product derivative methyl cinnamate,which indicates that this intermediate appears to be universal in P450-catalyzed aromatic hydroxylation.Our work not only provides the most direct evidence for the arene oxide pathway and new insights into the regioselectivity involved in P450-catalyzed aromatic hydroxylation,but also supplies a new synthetic approach to achieve the dearomatization of aromatic compounds.展开更多
A dearomatization strategy using dicetolic acid(6)as the starting material to synthesize the core intermediate(10R,13S,14S)-10,13-dimethyl-7,10,11,12,13,14,15,16-octahydro-3H-cyclopenta[a]phenanthrene-3,17(6H)-dione(2...A dearomatization strategy using dicetolic acid(6)as the starting material to synthesize the core intermediate(10R,13S,14S)-10,13-dimethyl-7,10,11,12,13,14,15,16-octahydro-3H-cyclopenta[a]phenanthrene-3,17(6H)-dione(20)for the formal synthesis of dydrogesterone is presented,achieving a total yield of 21%over nine steps.This approach features an environmentally friendly carbonyl protection strategy and efficient Heck coupling,while avoiding harsh conditions and hazardous reagents throughout the entire process.展开更多
The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficie...The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficient synthetic strategy include the following:(1)(+)-Taberdicatine B and(+)-tabernabovine B were accessed from common advanced intermediates by varying the substituents;(2) A one-pot asymmetric bromocyclization/hydrolysis was explored to assemble HPI skeleton;(3) Dieckmann condensation to form β-keto ester for the assembly of seven-membered ring;(4) An ester reduction/amide semireduction/cyclization sequence was applied to form the cage-like framework.展开更多
Catalytic asymmetric dearomatization(CADA)has emerged as a powerful strategy for transforming planar aromatic systems into three-dimensional chiral architectures[1].Notably,the Büchner reaction and arene cyclopro...Catalytic asymmetric dearomatization(CADA)has emerged as a powerful strategy for transforming planar aromatic systems into three-dimensional chiral architectures[1].Notably,the Büchner reaction and arene cyclopropanation excel in constructing complex polycyclic frameworks[2].However,current methods predominantly rely on diazo compounds as carbene precursors(Scheme1a),which pose safety risks and limit functional group compatibility.展开更多
Linear alkyl benzenes （LABs） are the main materials for detergent production. The presence of aromatic compounds in this material can decrease the quality of the final product and enhance the deactivation rate of ca...Linear alkyl benzenes （LABs） are the main materials for detergent production. The presence of aromatic compounds in this material can decrease the quality of the final product and enhance the deactivation rate of catalysts. In this research we used zeolite NaX for de-aromatization of the recycled paraffin from the alkylation unit of an LAB production complex. The effect of different parameters on the removal efficiency of adsorbent was studied and optimized. To study the re-usability of the adsorbent, the breakthrough curves were obtained by using a fixed bed column filled with the adsorbent. The results indicated that the adsorbent capacity remained unchanged after three regeneration cycles. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. It was concluded that the Langmuir model agreed well with the experimental data. The calculated thermodynamic parameters of the adsorption showed that the adsorption process was spontaneous and exothermic. The reaction rate was estimated by the pseudo-second order kinetic model.展开更多
We report herein a palladium-catalyzed diarylative dearomatization of indole by employing thioester and arylboronic acid as the aryl electrophiles.The reaction involved a decarbonylation/migratory insertion/terminal S...We report herein a palladium-catalyzed diarylative dearomatization of indole by employing thioester and arylboronic acid as the aryl electrophiles.The reaction involved a decarbonylation/migratory insertion/terminal Suzuki coupling procedure.Substrates bearing various functional groups are well tolerated in the reaction,affording the diarylated indoline skeletons in moderate to good yields.展开更多
A bicyclo[2.2.2]octane C/D ring system, with a lactonic ring at C-8 and C-9, of the atisine-type C20-diterpenoid alkaloids, was successfully synthesized, using an oxidative dearomatization/intramolecular Diels-Alder r...A bicyclo[2.2.2]octane C/D ring system, with a lactonic ring at C-8 and C-9, of the atisine-type C20-diterpenoid alkaloids, was successfully synthesized, using an oxidative dearomatization/intramolecular Diels-Alder reaction.展开更多
A catalytic asymmetric hydroxylative dearomatization reaction has been disclosed,and the products can smoothly transform into spiroannulation adducts by simply treated with a base under mild conditions.Novel in-situ g...A catalytic asymmetric hydroxylative dearomatization reaction has been disclosed,and the products can smoothly transform into spiroannulation adducts by simply treated with a base under mild conditions.Novel in-situ generated magnesium catalytic methods are developed by application of combinational ligands.Related concise transformaitons of the spiroannulation adducts have been carried out.展开更多
A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones...A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones.Mild reaction conditions,high diastereoselectivity,a broad substrate scope,effective functional group tolerance,and reasonable to remarkable yields were observed.展开更多
A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindol...A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindoles containing fused azaindoline architectures and vicinal quaternary centers in excellent yields（up to 96%） with high regio- and diastereoselectivity（dr 〉 19：1）. Moderate enantioselectivity（79% ee） was obtained by employing a chiral DMAP-type Lewis base catalyst.展开更多
Photo‐catalyzed tandem dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) was achieved,which affords spirocyclic carboxylic acids under mild conditions.The reaction has good functional grou...Photo‐catalyzed tandem dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) was achieved,which affords spirocyclic carboxylic acids under mild conditions.The reaction has good functional group tolerance with high yields.Mechanism studies indicate that the transformation was realized via intramolecular radical addition and nucleophilic addition.展开更多
The copper-catalyzed directed dearomatization of indoles with the assistance of directing groups has been developed for the synthesis of 2,3-diazido indolines with good yields and excellent diastereoselectivities in a...The copper-catalyzed directed dearomatization of indoles with the assistance of directing groups has been developed for the synthesis of 2,3-diazido indolines with good yields and excellent diastereoselectivities in aqueous solution.The resultant 2,3-diazides can be smoothly converted to other functional groups,including vicinal diamines,triazoles and benzotriazoles,in a single step.展开更多
A visible-light-induced spirocyclizative hydroarylation via reductive dearomatization of a series of non activated arenes including 2-phenyl indoles and naphthalene derivatives under mild conditions is de scribed.An i...A visible-light-induced spirocyclizative hydroarylation via reductive dearomatization of a series of non activated arenes including 2-phenyl indoles and naphthalene derivatives under mild conditions is de scribed.An intriguing chemoselective dearomative hydroarylation of 2-phenyl indoles is presented.Th dearomative hydroarylation protocol rapidly delivers valuable spirocycles with carbon-carbon doub bonds from readily accessible aromatic precursors in a single step.展开更多
Atom-and step-economy in IBX assisted diversity-oriented synthesis is achieved with a versatile AQ auxiliary α-amino acid analogs offering rapid access to polycyclic spiro-quinolines featuring a quaternary stereocent...Atom-and step-economy in IBX assisted diversity-oriented synthesis is achieved with a versatile AQ auxiliary α-amino acid analogs offering rapid access to polycyclic spiro-quinolines featuring a quaternary stereocenter in 20%–91% yields under mild conditions via 7,8-dearomatization of quinolines. Free of a preinstalled activation group is highlight of this intramolecular oxidation spiroannulation tandem reaction. This type of N-heterospirocycles, traditionally difficult to access, may open the door to a potentially interest scaffold for synthetic and medicinal chemistry.展开更多
Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral ...Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral polycyclic indolines. However, these reactions have been mostly limited to transition-metal catalysts, and the related chiral Br■nsted acid catalysis has been scarcely reported. Herein, we disclose a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides by direct activation of alkynes. This metal-free method enables the practical and atom-economical construction of an array of valuable chiral polycyclic indolines in moderate to good yields with high enantioselectivities.展开更多
A catalytic asymmetric brominative dearomatization reaction of benzofuran derivatives was achieved by using hydroquinidine 1,4-phthalazinediyl diether [（DHQ）_2PHAL] as the catalyst and N-bromoacetamide（NBAc） as th...A catalytic asymmetric brominative dearomatization reaction of benzofuran derivatives was achieved by using hydroquinidine 1,4-phthalazinediyl diether [（DHQ）_2PHAL] as the catalyst and N-bromoacetamide（NBAc） as the brominating reagent. A series of brominated spiro[benzofuran-2,5＇-oxazoles] bearing two contiguous stereogenic centers were obtained in high yields（up to 99%） with excellent enantioselectivity（up to 97% ee）.展开更多
Bichner reaction,as a unique type of expansive dearomatization,has become a practical strategy for the straightforward assembly of valuable functionalized cycloheptatrienes from ubiquitous aromatic precursors.Although...Bichner reaction,as a unique type of expansive dearomatization,has become a practical strategy for the straightforward assembly of valuable functionalized cycloheptatrienes from ubiquitous aromatic precursors.Although the asymmetric version has been investigated since the early 1990s,enantioselective Bichner reaction is still limited by the catalyst type and substrate scope.This review aims to propose the limitation and possible development direction of this field by summarizing the evolution of catalytic asymmetric Bichner reaction,which is organized on the basis of intra-and intermolecular reactions.Considering the different metal carbene precursors,the reactions are further classified by carbene sources.展开更多
Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong backgr...Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong background reaction and poses a daunting challenge to chemists for developing the catalytic asymmetric version. Reported herein is the first catalytic asymmetric dearomative azo-Diels–Alder reaction between2-vinylindoles and triazoledione. This protocol makes use of the high energy barrier of dearomatization to avert the strong background reaction of azo-Diels–Alder reaction, allowing the implementation of the projected reaction at ambient temperature. Density functional theory calculations have been performed to gain insights into the reaction mechanism and the origins of the enantioselectivity. By using this method,a variety of tetracyclic indole derivatives have been readily prepared in good to excellent yields and with excellent diastereo-and enantio–selectivities(33 examples, up to 97% yield and >99% ee, >20:1 dr).展开更多
基金supported by the NSFC-Joint Foundation of Yunnan Province(U1902213)Chongqing Municipal Natural Science Foundation(cstc2018jcyjAX0388)+3 种基金the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)Southeast Asia Biodiversity Research Institute,CAS(2017CASSEABRIQG003)State Key Laboratory of Phytochemistry and Plant Resources in West China(P2017-KF02 and P2019-ZZ05)the Natural Sciences Foundation of Yunnan Province(2019FA003).
文摘A series of dearomatized isoprenylated acylphloroglucinols derivatives,hyperhenols A-E(1-5),as well as seven known analogues(6-12),were characterized from Hypericum henryi.Their structures were determined by combination of NMR,ECD spectroscopy,and X-ray difraction analysis.Compounds 1 and 6-8 were tested to exhibit potential antitumor properties,of which 6 and 7 inhibited cell growth through inducing apoptosis and cell cycle arrest.In addition,these compounds could induce autophagy and PINK1/Parkin-mediated mitophagy in cancer cell lines,as well as suppress lung cancer A549 cells metastasis in vitro.
基金supported by the National Natural Science Foundation of China(22125108 and 22121001 for Ye LW,22122109 and 22271253 for Hong X)the National Key R&D Program of China(2022YFA1504301,Hong X)+8 种基金the Zhejiang Provincial Natural Science Foundation of China(LDQ23B020002,Hong X)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(SNZJU-SIAS-006,Hong X)the Beijing National Laboratory for Molecular Sciences(BNLMS202102,Hong X)the CAS Youth Interdisciplinary Team(JCTD-2021-11,Hong X)the Fundamental Research Funds for the Central Universities(226-2022-00140,226-2022-00224,and 226-2023-00115,Hong X)the State Key Laboratory of Physical Chemistry of Solid Surfaces(202210,Hong X)the Leading Innovation Team grant from the Department of Science and Technology of Zhejiang Province(2022R01005,Hong X)the Natural Science Foundation of Jiangsu Province(BK20211059)National Found for Fostering Talents of Basic Science(NFFTBS,J1310024).
文摘Herein,we disclose a highly regio-/chemoselective tandem asymmetric dearomatized halofunctionalization reaction of phenoltethered ynamides with diverse electrophilic halogenation sources in a catalyst-free manner for the practical and rapid assembly of a series of halogenated spirocyclic enones.Besides,the related dearomatized selenation and protonation are also achieved,affording the corresponding selenated and protonated spirocycles in high efficiency.Moreover,the enantioselectivities of these products can be perfectly induced by Evans auxiliaries(99%ees).Significantly,this protocol not only represents the first tandem asymmetric halofunctionalization reaction of phenol derivatives,but also constitutes the first asymmetric halogenation/selenation of ynamides.Theoretical calculations indicate a remote induction model of Evans chiral auxiliary-attached keteniminium.
文摘P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process of aromatic hydroxylation and mechanism of regioselectivity catalyzed by cytochrome P450 monooxygenases remained ambiguous.Here,we have resolved these issues.With a stable chiral organofluorine probe,and especially with X-ray data of two isolated arene oxides derivatives,we demonstrate that an arene oxide pathway is definitely involved in P450-catalyzed aromatic hydroxylation.By the capture,isolation,identification and reactivity exploration of the arene 1,2-oxide and arene 2,3-oxide intermediates,together with advanced QM calculations,the mechanism of how two intermediates go to the same product has been elucidated.In addition to the model substrate,we also confirmed that an arene oxide intermediate is involved in the P450-catalyzed hydroxylation pathway of a natural product derivative methyl cinnamate,which indicates that this intermediate appears to be universal in P450-catalyzed aromatic hydroxylation.Our work not only provides the most direct evidence for the arene oxide pathway and new insights into the regioselectivity involved in P450-catalyzed aromatic hydroxylation,but also supplies a new synthetic approach to achieve the dearomatization of aromatic compounds.
文摘A dearomatization strategy using dicetolic acid(6)as the starting material to synthesize the core intermediate(10R,13S,14S)-10,13-dimethyl-7,10,11,12,13,14,15,16-octahydro-3H-cyclopenta[a]phenanthrene-3,17(6H)-dione(20)for the formal synthesis of dydrogesterone is presented,achieving a total yield of 21%over nine steps.This approach features an environmentally friendly carbonyl protection strategy and efficient Heck coupling,while avoiding harsh conditions and hazardous reagents throughout the entire process.
基金the Qingdao Marine Science and Technology Center(No.2022QNLM030003-2)the Fundamental Research Funds for the Central Universities,Taishan Scholar Program of Shandong Province(No.tsqn202103152)National Natural Science Foundation of China(No.22171251) for financial support。
文摘The first total synthesis of(+)-taberdicatine B and(+)-tabernabovine B has been accomplished in 10steps with 26.9% overall yield and 15 steps with 7.3% overall yield,respectively.The prominent features of this efficient synthetic strategy include the following:(1)(+)-Taberdicatine B and(+)-tabernabovine B were accessed from common advanced intermediates by varying the substituents;(2) A one-pot asymmetric bromocyclization/hydrolysis was explored to assemble HPI skeleton;(3) Dieckmann condensation to form β-keto ester for the assembly of seven-membered ring;(4) An ester reduction/amide semireduction/cyclization sequence was applied to form the cage-like framework.
文摘Catalytic asymmetric dearomatization(CADA)has emerged as a powerful strategy for transforming planar aromatic systems into three-dimensional chiral architectures[1].Notably,the Büchner reaction and arene cyclopropanation excel in constructing complex polycyclic frameworks[2].However,current methods predominantly rely on diazo compounds as carbene precursors(Scheme1a),which pose safety risks and limit functional group compatibility.
基金Financial support of the Iran Chemical Industries Investment Company is greatly acknowledged
文摘Linear alkyl benzenes （LABs） are the main materials for detergent production. The presence of aromatic compounds in this material can decrease the quality of the final product and enhance the deactivation rate of catalysts. In this research we used zeolite NaX for de-aromatization of the recycled paraffin from the alkylation unit of an LAB production complex. The effect of different parameters on the removal efficiency of adsorbent was studied and optimized. To study the re-usability of the adsorbent, the breakthrough curves were obtained by using a fixed bed column filled with the adsorbent. The results indicated that the adsorbent capacity remained unchanged after three regeneration cycles. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. It was concluded that the Langmuir model agreed well with the experimental data. The calculated thermodynamic parameters of the adsorption showed that the adsorption process was spontaneous and exothermic. The reaction rate was estimated by the pseudo-second order kinetic model.
基金the Shanghai Institute of Materia Medicathe Chinese Academy of Sciences+4 种基金the National Natural Science Foundation of China(Nos.21772211 and 21920102003)the Youth Innovation Promotion Association CAS(Nos.2014229 and 2018293)the Science and Technology Commission of Shanghai Municipality(Nos.17JC1405000 and 18431907100)the Program of Shanghai Academic Research Leader(No.19XD1424600)the National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”,China(No.2018ZX09711002-006)for financial support。
文摘We report herein a palladium-catalyzed diarylative dearomatization of indole by employing thioester and arylboronic acid as the aryl electrophiles.The reaction involved a decarbonylation/migratory insertion/terminal Suzuki coupling procedure.Substrates bearing various functional groups are well tolerated in the reaction,affording the diarylated indoline skeletons in moderate to good yields.
基金the financial support provided by the National Science Foundation of China(No.81273387)
文摘A bicyclo[2.2.2]octane C/D ring system, with a lactonic ring at C-8 and C-9, of the atisine-type C20-diterpenoid alkaloids, was successfully synthesized, using an oxidative dearomatization/intramolecular Diels-Alder reaction.
基金the financial support from the National Natural Science Foundation of China (Nos. 21901092, 21807053)Innovation Fund for Medical Sciences (No. 2019-12M-5-074)+2 种基金Program for Chang-jiang Scholars and Innovative Research Team in University (PCSIRT) (No. IRT_15R27)the Funds for Fundamental Research Creative Groups of Gansu Province (No. 20JR5RA310)the Fundamental Research Funds for the Central Universities (Nos. lzujbky2020-49, 2021-kb21)
文摘A catalytic asymmetric hydroxylative dearomatization reaction has been disclosed,and the products can smoothly transform into spiroannulation adducts by simply treated with a base under mild conditions.Novel in-situ generated magnesium catalytic methods are developed by application of combinational ligands.Related concise transformaitons of the spiroannulation adducts have been carried out.
文摘A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones.Mild reaction conditions,high diastereoselectivity,a broad substrate scope,effective functional group tolerance,and reasonable to remarkable yields were observed.
基金financial support from the NSFC(21572135 and 21321061)
文摘A mild and efficient dearomatic [3＋2] annulation reaction of 3-nitro-7-azaindoles and Morita Baylis Hillman carbonates from isatins was developed catalyzed by DMAP, affording the corresponding polycyclic spirooxindoles containing fused azaindoline architectures and vicinal quaternary centers in excellent yields（up to 96%） with high regio- and diastereoselectivity（dr 〉 19：1）. Moderate enantioselectivity（79% ee） was obtained by employing a chiral DMAP-type Lewis base catalyst.
文摘Photo‐catalyzed tandem dearomatization/carboxylation of benzyl o‐halogenated aryl ether with CO_(2) was achieved,which affords spirocyclic carboxylic acids under mild conditions.The reaction has good functional group tolerance with high yields.Mechanism studies indicate that the transformation was realized via intramolecular radical addition and nucleophilic addition.
基金the National Natural Science Foundation of China(Nos.21472172,21272212)Natural Science Foundation of Zhejiang Province(No.LY17B060009)。
文摘The copper-catalyzed directed dearomatization of indoles with the assistance of directing groups has been developed for the synthesis of 2,3-diazido indolines with good yields and excellent diastereoselectivities in aqueous solution.The resultant 2,3-diazides can be smoothly converted to other functional groups,including vicinal diamines,triazoles and benzotriazoles,in a single step.
基金the financial supports from the National Natural Science Foundation of China(Nos.22022111,21871257,21801240)the Natural Science Foundation of Fujian Province(No.2020J02008)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)。
文摘A visible-light-induced spirocyclizative hydroarylation via reductive dearomatization of a series of non activated arenes including 2-phenyl indoles and naphthalene derivatives under mild conditions is de scribed.An intriguing chemoselective dearomative hydroarylation of 2-phenyl indoles is presented.Th dearomative hydroarylation protocol rapidly delivers valuable spirocycles with carbon-carbon doub bonds from readily accessible aromatic precursors in a single step.
基金the National Natural Science Foundation of China (Nos. 22101074, 21877206, and 21772032)the 111 Project (No. D17007)+2 种基金Excellent Youth Foundation of Henan Scientific Committee (No. 222300420012)China Postdoctoral Science Foundation (No. 2019M660173)the Natural Science Foundation of Henan Province (No. 202300410233)。
文摘Atom-and step-economy in IBX assisted diversity-oriented synthesis is achieved with a versatile AQ auxiliary α-amino acid analogs offering rapid access to polycyclic spiro-quinolines featuring a quaternary stereocenter in 20%–91% yields under mild conditions via 7,8-dearomatization of quinolines. Free of a preinstalled activation group is highlight of this intramolecular oxidation spiroannulation tandem reaction. This type of N-heterospirocycles, traditionally difficult to access, may open the door to a potentially interest scaffold for synthetic and medicinal chemistry.
基金financial support from the National Natural Science Foundation of China(Nos.22125108,22101238,92056104 and 21772161)the China Postdoctoral Science Foundation(No.2020M680087)+3 种基金the Natural Science Foundation of Fujian Province of China(No.2019J02001)the President Research Funds from Xiamen University(No.20720210002)the Fundamental Research Funds for the Central Universities(No.20720202008)NFFTBS(No.J1310024)。
文摘Catalytic asymmetric dearomatization of indoles and alkynes has received much attention in the past decade because this strategy offers an attractive and alternative way for the efficient synthesis of valuable chiral polycyclic indolines. However, these reactions have been mostly limited to transition-metal catalysts, and the related chiral Br■nsted acid catalysis has been scarcely reported. Herein, we disclose a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides by direct activation of alkynes. This metal-free method enables the practical and atom-economical construction of an array of valuable chiral polycyclic indolines in moderate to good yields with high enantioselectivities.
基金the National Key R&D Program of China (No. 2016YFA0202900)National Basic Research Program of China (No.2015CB856600)+1 种基金the National Natural Science Foundation of China (Nos. 21332009, 21421091)the Chinese Academy of Sciences (Nos. XDB20000000, QYZDY-SSW-SLH012) for generous financial support
文摘A catalytic asymmetric brominative dearomatization reaction of benzofuran derivatives was achieved by using hydroquinidine 1,4-phthalazinediyl diether [（DHQ）_2PHAL] as the catalyst and N-bromoacetamide（NBAc） as the brominating reagent. A series of brominated spiro[benzofuran-2,5＇-oxazoles] bearing two contiguous stereogenic centers were obtained in high yields（up to 99%） with excellent enantioselectivity（up to 97% ee）.
基金support from MoST(No.2021YFC2100100)the National Natural Science Foundation of China(No.22125108)Yunnan Normal University,and Applied Basic Research Projects of Yunnan Province(No.202101AT070217).
文摘Bichner reaction,as a unique type of expansive dearomatization,has become a practical strategy for the straightforward assembly of valuable functionalized cycloheptatrienes from ubiquitous aromatic precursors.Although the asymmetric version has been investigated since the early 1990s,enantioselective Bichner reaction is still limited by the catalyst type and substrate scope.This review aims to propose the limitation and possible development direction of this field by summarizing the evolution of catalytic asymmetric Bichner reaction,which is organized on the basis of intra-and intermolecular reactions.Considering the different metal carbene precursors,the reactions are further classified by carbene sources.
基金the generous financial support from Natural Science Foundation of Henan Province (No.222300420084)application research plan of Key Scientific Research Projects in Colleges and Universities of Henan Province (No.22A150056)+1 种基金the Youth Innovation Team Program in Colleges and Universities of Shandong Province (No.2022KJ228)National Natural Science Foundation of China (No.22208302)。
文摘Due to the high electrophilic nature of azo-dienophiles, azo-Diels–Alder proceeds rapidly even without the need of a catalyst and is therefore regarded as the “click reaction”. This spontaneity causes strong background reaction and poses a daunting challenge to chemists for developing the catalytic asymmetric version. Reported herein is the first catalytic asymmetric dearomative azo-Diels–Alder reaction between2-vinylindoles and triazoledione. This protocol makes use of the high energy barrier of dearomatization to avert the strong background reaction of azo-Diels–Alder reaction, allowing the implementation of the projected reaction at ambient temperature. Density functional theory calculations have been performed to gain insights into the reaction mechanism and the origins of the enantioselectivity. By using this method,a variety of tetracyclic indole derivatives have been readily prepared in good to excellent yields and with excellent diastereo-and enantio–selectivities(33 examples, up to 97% yield and >99% ee, >20:1 dr).
