The structure of osthole has been modified to improve its larvicidal activity against mosquitoes. A new efficient synthesis of osthole derivatives with Grignard reagents has been developed, which employs CuI and LiCI ...The structure of osthole has been modified to improve its larvicidal activity against mosquitoes. A new efficient synthesis of osthole derivatives with Grignard reagents has been developed, which employs CuI and LiCI as pro- moters and covers a broad range of substrates to afford the corresponding products in mild to good yields （up to 83%）. Bio-activity evaluation showed that several products exhibited better activities than osthole.展开更多
One\|pot”reaction of 1,3,5 tribromobenzene with nonylmagnesium bromide,prepared by 1\|bromononane with magnesium in THF,catalyzed by Ni(PPh\-3)\-2Cl\-2,was used to obtain hyperbranched polyphenylene 1.The macromolecu...One\|pot”reaction of 1,3,5 tribromobenzene with nonylmagnesium bromide,prepared by 1\|bromononane with magnesium in THF,catalyzed by Ni(PPh\-3)\-2Cl\-2,was used to obtain hyperbranched polyphenylene 1.The macromolecule was characterized by GPC with molecular weight M n=4247 and polydispersity PD =1 36.Under the conditin of Heck reaction catalyzed by palladium\|complexes,the terminal bromine groups on this macromolecule coupled with styrene and phenylacetylene,respectively,to provide correspondign hyperbranched polyphenylene 2 and 3 with stilbenyl and diphenylacetyl fluorophores on their surface.These two polymers both exhibited two bands E\-1 and E\-2 at near 260 nm and 300 nm in their UV spectra.In their powder photoluminescence spectra,the maximum emitting peaks at 401 nm and 386 nm in the range of blue luminescence were observed,respectively.展开更多
A new synthetic method of ketones from substituted benzimidazolium salts and Grignard reagents is reported. The influences of the various Grignard reagents on the yield of ketones and the mechanism are discussed.
We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） wit...We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） with Grignard reagent （1.3 mmol） mediated by NiCl2 （4 mol%） and （p-CH3Ph）3P （8 mol%） in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature.展开更多
1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of pr...1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.展开更多
The precise synthesis of polymer with narrow molecular weight distribution(?)and well-defined architectures is very essential to exploring the functions and properties of polymer materials.Here,a universal polymerizat...The precise synthesis of polymer with narrow molecular weight distribution(?)and well-defined architectures is very essential to exploring the functions and properties of polymer materials.Here,a universal polymerization method capable of low?and reactive hydrogen compatibility is reported by introducing super-Grignard reagents(R_(2)Mg?Li Cl)into polymer chemistry.Under mild conditions,various monomers,including nonpolar polystyrene and 4-methoxystyrene that cannot be initiated by Grignard reagents,and polar methacrylate,are successfully polymerized with full monomer conversion and low?.This approach is amenable to wide varieties of initiators,polymerization temperature,and feed ratio,which makes it attractive for applications in polymer synthesis.By adding methanol and water during the polymerization process,the reactive hydrogen compatibility of this method is confirmed,which makes this method avoid the rigorous restriction on polymerization conditions of anionic polymerization.Moreover,chain extension polymerization and block copolymerization are achieved and demonstrate the livingness of chain propagation,enabling the facile synthesis of well-defined macromolecular architectures.This work therefore expands the methodology libraries of living polymerization,which may cause inspirations to polymer science.展开更多
A new approach to the synthesis of α,β unsaturated ketones from 1,2,3 trimethyl benzimidazolium salt via the condensation reaction with aldehydes followed by the addition reaction of Grignard reagents with quatern...A new approach to the synthesis of α,β unsaturated ketones from 1,2,3 trimethyl benzimidazolium salt via the condensation reaction with aldehydes followed by the addition reaction of Grignard reagents with quaternary C=N bond was provided.展开更多
The crystal structure of 7α-[（R）-1-hydroxyl-1-methyl-3-（thien-2-yl）propyl]-6,14-endoethanotetrahydrothebaine （C29H37NO4S, Mr=495.66） has been determined by single-crystal X-ray diffraction analysis. The crystal...The crystal structure of 7α-[（R）-1-hydroxyl-1-methyl-3-（thien-2-yl）propyl]-6,14-endoethanotetrahydrothebaine （C29H37NO4S, Mr=495.66） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs orthorhombic, space group P212121 with α=10.063（4）, b=12.571（5）, c=19.626（8）A°, V=2482.9（17）A°^3, Z=4, Dc=1.326 g/cm^3,μ=0.167 mm^-1, F（000）=1064, the final R=0.0537 and wR=0.0888. The C（7） substituent is l-hy-droxyl-1-methyl-3-（thienyl-2-）propyl group adopting R-configuration. The N-methyl group is located at the equatorial position as expected. The crystal structure shows the presence of intra- molecular hydrogen bonds, O（1）-H（1）…O（2）.展开更多
Z)-a-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of a-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(...Z)-a-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of a-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(PPh3)4 to afford (Z)-1,2-disubstituted vinylselenides 3, which were cross-coupled with Grignard reagents in the presence of (PPh3)2NiCl2 to give trisubstituted alkenes 4 stereoselectively in good yields.展开更多
The present paper narrates the addition of 5-trimethylsilylcyclohex-3-enone to Grig-nard reagent to give 1-substituted 5-trimethylsilylcyclohex-3-enol in a good yield. The stereochemistry of the addition reaction and ...The present paper narrates the addition of 5-trimethylsilylcyclohex-3-enone to Grig-nard reagent to give 1-substituted 5-trimethylsilylcyclohex-3-enol in a good yield. The stereochemistry of the addition reaction and their products are discussed.展开更多
A novel one-pot approach for the preparation of 2-mercaptobenzaldehyde, 2-mercaptocyclohex-l-enecarboxal- dehydes and 3-mercaptoacrylaldehydes [（Z）-3-mercapto-2-methyl-3-phenylacrylaldehyde, 3-mercapto-3-（o-tolyl）...A novel one-pot approach for the preparation of 2-mercaptobenzaldehyde, 2-mercaptocyclohex-l-enecarboxal- dehydes and 3-mercaptoacrylaldehydes [（Z）-3-mercapto-2-methyl-3-phenylacrylaldehyde, 3-mercapto-3-（o-tolyl）- acrylaldehyde）] starting from ortho-bromobenzaldehyde, 2-chlorocyclohex-l-enecarbaldehydes, （Z）-3-chloro-2- methyl-3-phenylacrylaldehyde and 3-chloro-3-（o-tolyl）acrylaldehyde is reported. The reaction of sulfur with the Grignard reagent of the acetal for the protection of the aldehyde group affords the title compounds through hydroly- sis with dilute hydrochloric acid in high yields.展开更多
A facile and efficient method for the formylation of Grignard reagent was reported, and a new approach for the preparation of aldehydes from Grignard reagent and benzimidazolium salts was provided.
l-α-biaomo-2,3,4,6-tetra-O-acetyl-D-giucopyranose reacts with Grignard eagents prepared frorn the acnvated magnesium under very mild condition to ellord C- glucosides in a very high yield compared with Grignard Reage...l-α-biaomo-2,3,4,6-tetra-O-acetyl-D-giucopyranose reacts with Grignard eagents prepared frorn the acnvated magnesium under very mild condition to ellord C- glucosides in a very high yield compared with Grignard Reagent prepared from usual method.β-anomer predominates in the reaction, mixture The configuration of anomers was assigned by 13C NMR spectra.展开更多
Allylsamarium bromide reacts with Q, 6 -unsaturated esters and a -alkyloxy carbonyl α, β-unsaturated esters to give l,2-addition and 1 .4-addition products respectively.
The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo (naphtho)pyran-3-carboxylic acids (1) with aromatic aldehydes in the presence of piperidine yielded4-styryl-3-carboxami-dopiperidyl coumarin derivatives 4. The...The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo (naphtho)pyran-3-carboxylic acids (1) with aromatic aldehydes in the presence of piperidine yielded4-styryl-3-carboxami-dopiperidyl coumarin derivatives 4. The reaction of hydrazine hydrate with 1gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1with primary amines afforded compounds 7―9. And the treatment of la with Grignard reagents afforded3-aroyl-4-methyl coumarin derivatives 10.展开更多
Grignard additions to a quinoxalinium salt were studied. Depending on the ratio of the reagents and reaction temperature, 1, 2, 3, 4-tetrahydroquinoxaline and 1, 2-dihydroquinoxaline derivatives could be resulted sele...Grignard additions to a quinoxalinium salt were studied. Depending on the ratio of the reagents and reaction temperature, 1, 2, 3, 4-tetrahydroquinoxaline and 1, 2-dihydroquinoxaline derivatives could be resulted selectively.展开更多
A practical and scalable synthesis route of acetylphenylboronic acids is described. Bromoacetophenones(compounds 3a, 3b) were ketalized with ethylene glycol and triethyl orthoformate to give bromo ketals(compounds 4a_...A practical and scalable synthesis route of acetylphenylboronic acids is described. Bromoacetophenones(compounds 3a, 3b) were ketalized with ethylene glycol and triethyl orthoformate to give bromo ketals(compounds 4a_4c) in 60_80% yields. Compounds 4a_4b were treated with a Grignard reagent and then exchanged with borate to give p- and m-acetylphenyl boronic acids(compounds 5a and 5b) in 80% and 56% yields, respectively. The o-form(compound 5c) was obtained in 61% yield via the BuLi method.展开更多
Polymer-supported selenovinyl bromide, easily prepared from polymer-supported selenenyl bromide with acetylene, reacts with different Grignard reagents using a step-by-step strategy to obtain （E）-1, 2-disubstituted ...Polymer-supported selenovinyl bromide, easily prepared from polymer-supported selenenyl bromide with acetylene, reacts with different Grignard reagents using a step-by-step strategy to obtain （E）-1, 2-disubstituted ethenes in good yields.展开更多
The preparation of carbosilane dendrimers with cores of myo-inositol and the outmost periphery groups of allyl groups has been reported. By using alternate hydrosilylation and alkenylation reactions, the dendrimer ha...The preparation of carbosilane dendrimers with cores of myo-inositol and the outmost periphery groups of allyl groups has been reported. By using alternate hydrosilylation and alkenylation reactions, the dendrimer have been carried up to the third generation with 48 allyl groups on the periphery.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21272129 and 21372133） and ＂111＂ Project of Ministry of Educa- tion of China （No. B06005）. We also thank Prof. Er-Cai Shang and Dr. Yan-Jun Guo for their kind advices.
文摘The structure of osthole has been modified to improve its larvicidal activity against mosquitoes. A new efficient synthesis of osthole derivatives with Grignard reagents has been developed, which employs CuI and LiCI as pro- moters and covers a broad range of substrates to afford the corresponding products in mild to good yields （up to 83%）. Bio-activity evaluation showed that several products exhibited better activities than osthole.
文摘One\|pot”reaction of 1,3,5 tribromobenzene with nonylmagnesium bromide,prepared by 1\|bromononane with magnesium in THF,catalyzed by Ni(PPh\-3)\-2Cl\-2,was used to obtain hyperbranched polyphenylene 1.The macromolecule was characterized by GPC with molecular weight M n=4247 and polydispersity PD =1 36.Under the conditin of Heck reaction catalyzed by palladium\|complexes,the terminal bromine groups on this macromolecule coupled with styrene and phenylacetylene,respectively,to provide correspondign hyperbranched polyphenylene 2 and 3 with stilbenyl and diphenylacetyl fluorophores on their surface.These two polymers both exhibited two bands E\-1 and E\-2 at near 260 nm and 300 nm in their UV spectra.In their powder photoluminescence spectra,the maximum emitting peaks at 401 nm and 386 nm in the range of blue luminescence were observed,respectively.
基金Project supported by the Provincial Natural Science Foundation of Shaaxi Province
文摘A new synthetic method of ketones from substituted benzimidazolium salts and Grignard reagents is reported. The influences of the various Grignard reagents on the yield of ketones and the mechanism are discussed.
基金financially supported by the Fundamental Research Funds for the Central Universities,Southwest University for Nationalities (No.12NZYTH03)the Natural Science Foundation of Southwest University for Nationalities (No.381010)+1 种基金the Project of Postgraduate Degree Construction,Southwest University for Nationalities (No.2013XWD-S0703)the State Administration of Foreign Experts Affairs project (No.2012-10)
文摘We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） with Grignard reagent （1.3 mmol） mediated by NiCl2 （4 mol%） and （p-CH3Ph）3P （8 mol%） in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature.
基金This work was supported by the NNSFC (No.29672004).
文摘1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
基金funding support from National Natural Science Foundation of China(NSFC,Nos.22271286 and 21971236)the Haixi Institute of CAS(No.CXZX-2017-P01)。
文摘The precise synthesis of polymer with narrow molecular weight distribution(?)and well-defined architectures is very essential to exploring the functions and properties of polymer materials.Here,a universal polymerization method capable of low?and reactive hydrogen compatibility is reported by introducing super-Grignard reagents(R_(2)Mg?Li Cl)into polymer chemistry.Under mild conditions,various monomers,including nonpolar polystyrene and 4-methoxystyrene that cannot be initiated by Grignard reagents,and polar methacrylate,are successfully polymerized with full monomer conversion and low?.This approach is amenable to wide varieties of initiators,polymerization temperature,and feed ratio,which makes it attractive for applications in polymer synthesis.By adding methanol and water during the polymerization process,the reactive hydrogen compatibility of this method is confirmed,which makes this method avoid the rigorous restriction on polymerization conditions of anionic polymerization.Moreover,chain extension polymerization and block copolymerization are achieved and demonstrate the livingness of chain propagation,enabling the facile synthesis of well-defined macromolecular architectures.This work therefore expands the methodology libraries of living polymerization,which may cause inspirations to polymer science.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No.2 9872 0 32 )andtheSpecialScienceResearchFoundationofEducationCommitteeofShaanxiProvince (No .98JK12 0 )
文摘A new approach to the synthesis of α,β unsaturated ketones from 1,2,3 trimethyl benzimidazolium salt via the condensation reaction with aldehydes followed by the addition reaction of Grignard reagents with quaternary C=N bond was provided.
基金The project was supported by the NNSFC (No. 30271492)
文摘The crystal structure of 7α-[（R）-1-hydroxyl-1-methyl-3-（thien-2-yl）propyl]-6,14-endoethanotetrahydrothebaine （C29H37NO4S, Mr=495.66） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs orthorhombic, space group P212121 with α=10.063（4）, b=12.571（5）, c=19.626（8）A°, V=2482.9（17）A°^3, Z=4, Dc=1.326 g/cm^3,μ=0.167 mm^-1, F（000）=1064, the final R=0.0537 and wR=0.0888. The C（7） substituent is l-hy-droxyl-1-methyl-3-（thienyl-2-）propyl group adopting R-configuration. The N-methyl group is located at the equatorial position as expected. The crystal structure shows the presence of intra- molecular hydrogen bonds, O（1）-H（1）…O（2）.
文摘Z)-a-Selanyl alkenyl Grignard reagents 2 were prepared conveniently by treatment of a-bromovinylselenides 1 with magnesium filings in THF. Intermediates 2 were reacted with alkyl iodides in the presence of CuI or Pd(PPh3)4 to afford (Z)-1,2-disubstituted vinylselenides 3, which were cross-coupled with Grignard reagents in the presence of (PPh3)2NiCl2 to give trisubstituted alkenes 4 stereoselectively in good yields.
基金Supported by the National Natural Science Foundation of China Youth Foundation of Tianjin
文摘The present paper narrates the addition of 5-trimethylsilylcyclohex-3-enone to Grig-nard reagent to give 1-substituted 5-trimethylsilylcyclohex-3-enol in a good yield. The stereochemistry of the addition reaction and their products are discussed.
基金We gratefully acknowledge the support by the Na- tional Natural Science Foundation of China （Nos. 20772072 and 20972087）.
文摘A novel one-pot approach for the preparation of 2-mercaptobenzaldehyde, 2-mercaptocyclohex-l-enecarboxal- dehydes and 3-mercaptoacrylaldehydes [（Z）-3-mercapto-2-methyl-3-phenylacrylaldehyde, 3-mercapto-3-（o-tolyl）- acrylaldehyde）] starting from ortho-bromobenzaldehyde, 2-chlorocyclohex-l-enecarbaldehydes, （Z）-3-chloro-2- methyl-3-phenylacrylaldehyde and 3-chloro-3-（o-tolyl）acrylaldehyde is reported. The reaction of sulfur with the Grignard reagent of the acetal for the protection of the aldehyde group affords the title compounds through hydroly- sis with dilute hydrochloric acid in high yields.
基金supported by the National Natural Science Foundation of China(Grant No.20172041)the Provincial Natural Science Foundation of Shaanxi Province(Grant No.2003B12).
文摘A facile and efficient method for the formylation of Grignard reagent was reported, and a new approach for the preparation of aldehydes from Grignard reagent and benzimidazolium salts was provided.
文摘l-α-biaomo-2,3,4,6-tetra-O-acetyl-D-giucopyranose reacts with Grignard eagents prepared frorn the acnvated magnesium under very mild condition to ellord C- glucosides in a very high yield compared with Grignard Reagent prepared from usual method.β-anomer predominates in the reaction, mixture The configuration of anomers was assigned by 13C NMR spectra.
文摘Allylsamarium bromide reacts with Q, 6 -unsaturated esters and a -alkyloxy carbonyl α, β-unsaturated esters to give l,2-addition and 1 .4-addition products respectively.
文摘The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo (naphtho)pyran-3-carboxylic acids (1) with aromatic aldehydes in the presence of piperidine yielded4-styryl-3-carboxami-dopiperidyl coumarin derivatives 4. The reaction of hydrazine hydrate with 1gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1with primary amines afforded compounds 7―9. And the treatment of la with Grignard reagents afforded3-aroyl-4-methyl coumarin derivatives 10.
文摘Grignard additions to a quinoxalinium salt were studied. Depending on the ratio of the reagents and reaction temperature, 1, 2, 3, 4-tetrahydroquinoxaline and 1, 2-dihydroquinoxaline derivatives could be resulted selectively.
基金the National Nature Science Foundation of China(No.30 17110)
文摘A practical and scalable synthesis route of acetylphenylboronic acids is described. Bromoacetophenones(compounds 3a, 3b) were ketalized with ethylene glycol and triethyl orthoformate to give bromo ketals(compounds 4a_4c) in 60_80% yields. Compounds 4a_4b were treated with a Grignard reagent and then exchanged with borate to give p- and m-acetylphenyl boronic acids(compounds 5a and 5b) in 80% and 56% yields, respectively. The o-form(compound 5c) was obtained in 61% yield via the BuLi method.
基金We are grateful to the National Natural Science Foundation of China(Project No.20332060)the CAS Academician Foundation of Zhejiang Province.
文摘Polymer-supported selenovinyl bromide, easily prepared from polymer-supported selenenyl bromide with acetylene, reacts with different Grignard reagents using a step-by-step strategy to obtain （E）-1, 2-disubstituted ethenes in good yields.
基金We are grateful to the National Natural Science Foundation of China for financial support(No.29874020).
文摘The preparation of carbosilane dendrimers with cores of myo-inositol and the outmost periphery groups of allyl groups has been reported. By using alternate hydrosilylation and alkenylation reactions, the dendrimer have been carried up to the third generation with 48 allyl groups on the periphery.
