Fluoroboric acid adsorbed on silica-gel（HBF4·SiO2） has been found to be an extremely efficient and recyclable catalyst for the preparation of β-enaminones and β-enamino esters under solvent-free conditions.
A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradi...A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradiation.展开更多
Electron impact induced fragmentation mechanisms of trans α aryl β enamino esters were investigated using mass analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data...Electron impact induced fragmentation mechanisms of trans α aryl β enamino esters were investigated using mass analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data. It was found that the main characteristic fragmentations of compounds studied were: an odd electron ion M +· -EtOH was formed by losing a neutral molecule of ethanol; and the skeletal rearrangements took place; and the ring opening reaction happened after losing a carbon monoxide; and the typical McLafferty rearrangement underwent in ester group. The cyclization reaction caused by losing neutral molecule of TsNH 2 due to the ortho effects of substituted group of aromatic ring was also observed.展开更多
The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and nin...The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and ninhydrin afforded functionalized spiro[indene-2,4＇-pyrrolo[3,4-b]pyridines] and spiro[acenaphthylene-1,4＇-pyrrolo[3,4-b]- pyridines] in good yields. The similar reaction of phenanthrene-9,10-dione resulted in the formation of the unexpected complex phenanthro[9＇, 10＇：4,5]furo[2,3-c]pyrrolo[3,4-b]pyrroles in satisfactory yields.展开更多
The novel 1,2-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-l-methyl-lH-pyrrole-2,5-diones with cinnamaldehy...The novel 1,2-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-l-methyl-lH-pyrrole-2,5-diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2-diaryl and 1,4-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones in comparable yields.展开更多
An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction me...An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction mechanism involves the formation of β-enamino ester and its sequential Michael addition to arylidene acetoacetate.展开更多
文摘Fluoroboric acid adsorbed on silica-gel（HBF4·SiO2） has been found to be an extremely efficient and recyclable catalyst for the preparation of β-enaminones and β-enamino esters under solvent-free conditions.
基金the National Natural Science Foundation of China(No.20472074)the Innovation Fund for 0utstanding Scholar of Henan Province(No.0621001100)for financial support.
文摘A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium（IV） ammonium nitrate （CAN） under ultrasonic irradiation.
文摘Electron impact induced fragmentation mechanisms of trans α aryl β enamino esters were investigated using mass analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data. It was found that the main characteristic fragmentations of compounds studied were: an odd electron ion M +· -EtOH was formed by losing a neutral molecule of ethanol; and the skeletal rearrangements took place; and the ring opening reaction happened after losing a carbon monoxide; and the typical McLafferty rearrangement underwent in ester group. The cyclization reaction caused by losing neutral molecule of TsNH 2 due to the ortho effects of substituted group of aromatic ring was also observed.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21572196） and the Priority Academic Program Development of Jiangsu Higher Education Institutions. We also want to give sincerely thanks to the Analysis Center of Yangzhou University for providing all necessary instruments for characterization of structures.
文摘The base promoted three-component reaction of β-enamino imide, malononitrile and various cyclic α-diketones in acetonitrile showed interesting molecular diversity. The reactions with acenaphthylene-1,2-dione and ninhydrin afforded functionalized spiro[indene-2,4＇-pyrrolo[3,4-b]pyridines] and spiro[acenaphthylene-1,4＇-pyrrolo[3,4-b]- pyridines] in good yields. The similar reaction of phenanthrene-9,10-dione resulted in the formation of the unexpected complex phenanthro[9＇, 10＇：4,5]furo[2,3-c]pyrrolo[3,4-b]pyrroles in satisfactory yields.
文摘The novel 1,2-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones were selectively synthesized in high yields by the base catalyzed cyclization reaction of 3-arylamino-l-methyl-lH-pyrrole-2,5-diones with cinnamaldehyde and its derivatives in acetonitrile at room temperature. However, when piperidinium trifluoroacetate was employed as catalyst, the reaction afforded a mixture of 1,2-diaryl and 1,4-diaryl substituted pyrrolo[3,4-b]pyridine-5,7-diones in comparable yields.
基金Supported by the National Natural Science Foundation of China(No.20972132)the Fund of Key Laboratory of Environmental Resource and Material,Jiangsu Province,China
文摘An efficient synthetic protocol for the 1,4-diaryl-1,4-dihydropyridines was developed via the domino four-component reaction of arylamine,acetylenedicarboxylate,aromatic aldehyde and ethyl acetoacetate.The reaction mechanism involves the formation of β-enamino ester and its sequential Michael addition to arylidene acetoacetate.
