The three-component reaction of triphenylphosphine,dimethyl hex-2-en-4-ynedioate and arylidene N,N’-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1,3-disubstituted 7,9-diazas...The three-component reaction of triphenylphosphine,dimethyl hex-2-en-4-ynedioate and arylidene N,N’-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1,3-disubstituted 7,9-diazaspiro[4.5]dec-1-enes in good yields and with high diastereoselectivity.However,the similar three-component reaction with arylidene Meldrum acids resulted in a mixtures of cis/trans-1,2-disubstituted 7,9-dioxaspiro[4.5]dec-1-enes.Additionally,the three-component reaction of triphenylphosphine,dimethyl but-2-ynedioate and arylidene Meldrum acids gave polysubstituted 5-(triphe nyl-λ~5-phosphanylidene)cyclopenta-1,3-die nes.A plausible reaction mechanism was proposed for the formation of various products with different regioselectivity and diastereoselectivity.展开更多
A Rh(Ⅰ)-catalyzed highly regio-and enantioselective allylic alkylation of Meldrum acid with racemic allylic substrates bearing alkyl groups has been developed.The applying of chiral bisoxazopinephosphine ligand is es...A Rh(Ⅰ)-catalyzed highly regio-and enantioselective allylic alkylation of Meldrum acid with racemic allylic substrates bearing alkyl groups has been developed.The applying of chiral bisoxazopinephosphine ligand is essential for the high yields and selectivities.This method provides a rapid access to various chiral β-alkyl-γ,δ-unsaturated carboxylic acids and their derivatives.展开更多
A series of novel Meldrum＇s acid C60 derivatives were prepared in moderate yields from a convenient one-pot reaction of C60, the Meldrum＇s acid derivatives, 12 and 1,8-diazabicyclo-[5,4,0]-undec-7-ene （DBU） in tol...A series of novel Meldrum＇s acid C60 derivatives were prepared in moderate yields from a convenient one-pot reaction of C60, the Meldrum＇s acid derivatives, 12 and 1,8-diazabicyclo-[5,4,0]-undec-7-ene （DBU） in toluene at room temperature under nitrogen atmosphere. All the new compounds were fully characterized by the spectral data and elemental analysis. A carbene intermediate mechanism was proposed for this reaction.展开更多
Six 4-aryl-5-methoxylcarbonyl-6-methyl-3,4-dihydropyrid-2-ones have been synthesized by the reaction of aromatic aldehyde, methyl acetoactate, meldrum's acid and ammonium acetate under microwave irradiation withou...Six 4-aryl-5-methoxylcarbonyl-6-methyl-3,4-dihydropyrid-2-ones have been synthesized by the reaction of aromatic aldehyde, methyl acetoactate, meldrum's acid and ammonium acetate under microwave irradiation without solvent. The method has advantages of rapidity, mild condition, without solvent and higher yield.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21572196)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The three-component reaction of triphenylphosphine,dimethyl hex-2-en-4-ynedioate and arylidene N,N’-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1,3-disubstituted 7,9-diazaspiro[4.5]dec-1-enes in good yields and with high diastereoselectivity.However,the similar three-component reaction with arylidene Meldrum acids resulted in a mixtures of cis/trans-1,2-disubstituted 7,9-dioxaspiro[4.5]dec-1-enes.Additionally,the three-component reaction of triphenylphosphine,dimethyl but-2-ynedioate and arylidene Meldrum acids gave polysubstituted 5-(triphe nyl-λ~5-phosphanylidene)cyclopenta-1,3-die nes.A plausible reaction mechanism was proposed for the formation of various products with different regioselectivity and diastereoselectivity.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.21602130 and 21961023)the startup funding from Shanghai Jiao Tong University.
文摘A Rh(Ⅰ)-catalyzed highly regio-and enantioselective allylic alkylation of Meldrum acid with racemic allylic substrates bearing alkyl groups has been developed.The applying of chiral bisoxazopinephosphine ligand is essential for the high yields and selectivities.This method provides a rapid access to various chiral β-alkyl-γ,δ-unsaturated carboxylic acids and their derivatives.
基金Project supported by the National Natural Science Foundation of China （No. 20532040）.
文摘A series of novel Meldrum＇s acid C60 derivatives were prepared in moderate yields from a convenient one-pot reaction of C60, the Meldrum＇s acid derivatives, 12 and 1,8-diazabicyclo-[5,4,0]-undec-7-ene （DBU） in toluene at room temperature under nitrogen atmosphere. All the new compounds were fully characterized by the spectral data and elemental analysis. A carbene intermediate mechanism was proposed for this reaction.
文摘Six 4-aryl-5-methoxylcarbonyl-6-methyl-3,4-dihydropyrid-2-ones have been synthesized by the reaction of aromatic aldehyde, methyl acetoactate, meldrum's acid and ammonium acetate under microwave irradiation without solvent. The method has advantages of rapidity, mild condition, without solvent and higher yield.
