In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was f...In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contactangle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorptionamount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly withincreasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both thehydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizin gacrylonitrile with vinyl carbohydrates.展开更多
Stereoselective transformation of Baylis-Hillman acetates I into corresponding (Z)-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodi...Stereoselective transformation of Baylis-Hillman acetates I into corresponding (Z)-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF4) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.展开更多
A simple and convenient procedure for stercoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethyls...A simple and convenient procedure for stercoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCI system to form selemde anions, which then undergo SN2' substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides.展开更多
Reaction of polystyrene-supported lithium selenide with 3-acetoxy-2-methylene-alkanoates afforded the corresponding allyl selenide resins and subsequent cleavage from the polymer by treating with methyl iodide to furn...Reaction of polystyrene-supported lithium selenide with 3-acetoxy-2-methylene-alkanoates afforded the corresponding allyl selenide resins and subsequent cleavage from the polymer by treating with methyl iodide to furnish (Z)-allyl iodides in good yields and high purities. The polymeric selenium reagent can be regenerated and reused. So it is a environmentally benign reagent.展开更多
An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)a...An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)acrylamides and organoboron reagents was successfully developed by using a 1,3-bis(2,6-diisopropylphenyl)acenaphthoimidazol-2-ylidene(AnIPr)-ligated oxazoline palladacycle.It enabled a very broad substrate scope tolerating different functional groups,electronic properties and steric bulkiness.Notably,it revealed a great potential to build diverse heterocycle-fused indoline alkaloids via the same intermediate 3-allyl-1,3-dimethylindolin-2-one.展开更多
Palladium-catalyzed cycloaddition reactions via Pd-π-allyl zwitterions have been established as significant synthetic transformations to enable numerous carbon-or heterocycles compounds that are key constituents of v...Palladium-catalyzed cycloaddition reactions via Pd-π-allyl zwitterions have been established as significant synthetic transformations to enable numerous carbon-or heterocycles compounds that are key constituents of various biologically active natural products and pharmaceuticals.In addition to the well-known Pd-π-allyl zwitterions,including palladium-trimethylenemethane and Pd-1,3/1,4-zwitterions,chemists have recently discovered new applications of several long ago reported but less-studied Pd-π-allyl zwitterions,which can straightforwardly and efficiently construct novel cyclic architectures.Meanwhile,some impressive newly designed zwitterions have been also developed.Those zwitterions are diverse and can serve as transient and highly reactive intermediates for the subsequent cyclization with various acceptors.In this review,we highlight recent advances in applications of these two types of zwitterions in the synthesis of complex polycyclics and medium-sized cyclic compounds.展开更多
Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid po...Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.展开更多
The reaction mechanisms of diene polymerization with homogeneous rare earth catalyst are studied by means of the spectra of ~1H-NMR, one-and two-dimensions ^(13)C-NMR. Based on the data of above NMR spectra, it is pro...The reaction mechanisms of diene polymerization with homogeneous rare earth catalyst are studied by means of the spectra of ~1H-NMR, one-and two-dimensions ^(13)C-NMR. Based on the data of above NMR spectra, it is proposed that the polymerization reaction proceeds according to the following mechanism: η~4-diene (cis-trans-)and η~3-allyl (syn-anti-).展开更多
The development of catalytic asymmetric methods that enable access to value-added functionalities or structures,exemplified by allylic alcohols,is a highly interesting yet challenging topic from both academic and indu...The development of catalytic asymmetric methods that enable access to value-added functionalities or structures,exemplified by allylic alcohols,is a highly interesting yet challenging topic from both academic and industrial perspectives.However,before recent advances in chemical catalysis,there were scarce protocols toward constructing enantioenriched tertiary allylic alcohol scaffolds.In this context,peptide-mimic phosphonium salts were found to be highly efficient in catalytic asymmetricα-hydroxylation ofα,β-unsaturated and/orβ,Y-unsaturated compounds with satisfactory regio-and stereochemical outcomes(up to 97%yield and 95%ee).This methodology tolerates a broad array of substrates and thus provides an expeditious and unified platform for the assembly of enantioenriched tertiary allylic alcohols by avoiding the use of additional reductants and expensive metal catalysts.Furthermore,the power of this protocol is enlarged by simple conditions and the use of air as a source of hydroxyl functionality.展开更多
Comprehensive Summary 2,3-Allenyl amines have shown wide applicability in biomedical and synthetic applications.Due to their enormous potential for applications,researchers have been dedicated to the development of me...Comprehensive Summary 2,3-Allenyl amines have shown wide applicability in biomedical and synthetic applications.Due to their enormous potential for applications,researchers have been dedicated to the development of methods for synthesizing 2,3-allenyl amines.Herein,a palladium-catalyzed three-component reaction of 2-alkynyl-1,4-diol dicarbonates,organoboronic acids,and nitrogen nucleophiles forming 2,3-allenyl amines with excellent regio-and chemo-selectivity has been developed.Substrate compatibility and synthetic applications have been demonstrated.Control experiments supported a mechanism involving 1,2,3-triene-Pd species and methylene-π-allyl palladium species.展开更多
The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides a...The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.展开更多
A simple and directα-allylic alkylation of unmodified aldehydes with allylic alcohols catalyzed by primary amine/Brønsted acid has been developed.The N,N-dimethylethylenediamine/TfOH was identified as the optima...A simple and directα-allylic alkylation of unmodified aldehydes with allylic alcohols catalyzed by primary amine/Brønsted acid has been developed.The N,N-dimethylethylenediamine/TfOH was identified as the optimal catalyst to promote this transformation via an enamine process in high yields(up to 88%)and with good diastereoselectivities(up to 9∶1).展开更多
基金The authors are grateful to the National Natural Science Foundation of China for financial support(Grant No.20074033).
文摘In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contactangle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorptionamount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly withincreasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both thehydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizin gacrylonitrile with vinyl carbohydrates.
基金Project (No. 2004C21032) supported by the Key Technology R & DProgram of Zhejiang Province, China
文摘Stereoselective transformation of Baylis-Hillman acetates I into corresponding (Z)-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF4) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.
基金Project (No. 2004C21032) supported by the Key Technologies R &D Program of Zhejiang Province, China
文摘A simple and convenient procedure for stercoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCI system to form selemde anions, which then undergo SN2' substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides.
基金the National Natural Science Foundation of China (No. 20562005) NSF of Jiangxi Province (No. 0620021) for financial support.
文摘Reaction of polystyrene-supported lithium selenide with 3-acetoxy-2-methylene-alkanoates afforded the corresponding allyl selenide resins and subsequent cleavage from the polymer by treating with methyl iodide to furnish (Z)-allyl iodides in good yields and high purities. The polymeric selenium reagent can be regenerated and reused. So it is a environmentally benign reagent.
基金National Natural Science Foundation of China(No.22101133)Natural Science Foundation of Jiangsu Province(No.BK20200768)and Nanjing Forestry University are greatly acknowledged.
文摘An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)acrylamides and organoboron reagents was successfully developed by using a 1,3-bis(2,6-diisopropylphenyl)acenaphthoimidazol-2-ylidene(AnIPr)-ligated oxazoline palladacycle.It enabled a very broad substrate scope tolerating different functional groups,electronic properties and steric bulkiness.Notably,it revealed a great potential to build diverse heterocycle-fused indoline alkaloids via the same intermediate 3-allyl-1,3-dimethylindolin-2-one.
基金the financial support from the National Natural Science Foundation of China(Nos.22071143 and 21772215)Start-up Funding for Scientific Research of Nanning Normal University(No.86612345)“BAGUI Scholar”Program of Guangxi Province of China。
文摘Palladium-catalyzed cycloaddition reactions via Pd-π-allyl zwitterions have been established as significant synthetic transformations to enable numerous carbon-or heterocycles compounds that are key constituents of various biologically active natural products and pharmaceuticals.In addition to the well-known Pd-π-allyl zwitterions,including palladium-trimethylenemethane and Pd-1,3/1,4-zwitterions,chemists have recently discovered new applications of several long ago reported but less-studied Pd-π-allyl zwitterions,which can straightforwardly and efficiently construct novel cyclic architectures.Meanwhile,some impressive newly designed zwitterions have been also developed.Those zwitterions are diverse and can serve as transient and highly reactive intermediates for the subsequent cyclization with various acceptors.In this review,we highlight recent advances in applications of these two types of zwitterions in the synthesis of complex polycyclics and medium-sized cyclic compounds.
文摘Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.
基金The Project is supported by "Laboratory of Physics & Chemistry, Academia Sinica" and "National Natural Science Foundation of China"
文摘The reaction mechanisms of diene polymerization with homogeneous rare earth catalyst are studied by means of the spectra of ~1H-NMR, one-and two-dimensions ^(13)C-NMR. Based on the data of above NMR spectra, it is proposed that the polymerization reaction proceeds according to the following mechanism: η~4-diene (cis-trans-)and η~3-allyl (syn-anti-).
基金Financial support was provided by the National Natural Science Foundation of China(22222109,21921002,22101189 and 22371190)the National Key R&DProgramof China(2018YFA0903500)+3 种基金Beijing National Laboratory for Molecular Sciences(BNLMs202101)Sichuan Science Foundation for Distinguished Young Scholars(2023NSFSC1921)Sichuan Provincial Natural Science Foundation(2022NSFSC1181,24NSFSC6590)Fundamental Research Funds from Sichuan University(2020SCUNL108)and Fundamental Research Funds for the Central Universities.
文摘The development of catalytic asymmetric methods that enable access to value-added functionalities or structures,exemplified by allylic alcohols,is a highly interesting yet challenging topic from both academic and industrial perspectives.However,before recent advances in chemical catalysis,there were scarce protocols toward constructing enantioenriched tertiary allylic alcohol scaffolds.In this context,peptide-mimic phosphonium salts were found to be highly efficient in catalytic asymmetricα-hydroxylation ofα,β-unsaturated and/orβ,Y-unsaturated compounds with satisfactory regio-and stereochemical outcomes(up to 97%yield and 95%ee).This methodology tolerates a broad array of substrates and thus provides an expeditious and unified platform for the assembly of enantioenriched tertiary allylic alcohols by avoiding the use of additional reductants and expensive metal catalysts.Furthermore,the power of this protocol is enlarged by simple conditions and the use of air as a source of hydroxyl functionality.
基金National Natural Science Foundation of China(No.21988101)is greatly appreciated.
文摘Comprehensive Summary 2,3-Allenyl amines have shown wide applicability in biomedical and synthetic applications.Due to their enormous potential for applications,researchers have been dedicated to the development of methods for synthesizing 2,3-allenyl amines.Herein,a palladium-catalyzed three-component reaction of 2-alkynyl-1,4-diol dicarbonates,organoboronic acids,and nitrogen nucleophiles forming 2,3-allenyl amines with excellent regio-and chemo-selectivity has been developed.Substrate compatibility and synthetic applications have been demonstrated.Control experiments supported a mechanism involving 1,2,3-triene-Pd species and methylene-π-allyl palladium species.
文摘The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.
基金This work was supported by the National Natural Science Foundation of China(21390400,21025208 and 21202171)the Ministry of Science and Technology(MoST)(2011CB808600)and the Chinese Academy of Sciences.
文摘A simple and directα-allylic alkylation of unmodified aldehydes with allylic alcohols catalyzed by primary amine/Brønsted acid has been developed.The N,N-dimethylethylenediamine/TfOH was identified as the optimal catalyst to promote this transformation via an enamine process in high yields(up to 88%)and with good diastereoselectivities(up to 9∶1).