Ionic liquids [Bmim]BF4 and [Bpy]BF4 were employed as environmentally benign media in Doebner condensation to synthesize α, β-unsaturated carboxylic acid. The good results showed that [Bmim]BF4 and [Bpy]BF4 were ef...Ionic liquids [Bmim]BF4 and [Bpy]BF4 were employed as environmentally benign media in Doebner condensation to synthesize α, β-unsaturated carboxylic acid. The good results showed that [Bmim]BF4 and [Bpy]BF4 were efficient media for Doebner condensation, which could be recycled easily. The highest yields could reach 93% and 90% in [Bmim]BF4 and [Bpy]BF4, respectively.展开更多
A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions ca...A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions can be used for the synthesis of drugs and biologically active organic compound of arsenic, antimony and bismuth. A possible new mechanism of the reaction is proposed.展开更多
Sinapinic acid is a widespread compound in vegetable material and is as such common in the human diet. Recently it has drawn attention because of its biological activities. Sinapinic acid can be synthesized from syrin...Sinapinic acid is a widespread compound in vegetable material and is as such common in the human diet. Recently it has drawn attention because of its biological activities. Sinapinic acid can be synthesized from syringaldehyde via the Knoevenagel-Doebner condensation. However this reaction is limited by the formation of 4-vinylsyringol after a second decarboxylation. To gain more detailed information about this reaction and to improve control over the formation of sinapinic acid, the concentration time history of syringaldehyde and the reaction products of this reaction have been monitored over time at different reaction temperatures. The formation of 4-vinylsyringol was found to be inhibited by performing the reaction at temperature below 80°C. This allows the reaction to be optimized for the production of sinapinic acid, with an optimal yield of 78% after 2.5 hours at 70°C.展开更多
A mild and efficient Knoevenagel-Doebner reaction from malonic acid and a wide range of aldehydes was catalyzed by a catalytic system consisting offlalanine and 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU）, affording th...A mild and efficient Knoevenagel-Doebner reaction from malonic acid and a wide range of aldehydes was catalyzed by a catalytic system consisting offlalanine and 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU）, affording the corresponding （E）-a,fl-unsaturated carboxylic acids in good to excellent yields and with high stereoselectivity. The advantage of the method is that the reaction could proceed smoothly at ambient temperature so that it can tolerate a variety of functional groups and avoid unnecessary side reactions.展开更多
基金supported by National 863 High-Tech Research and Development Program of China(No.2007AA05Z101).
文摘Ionic liquids [Bmim]BF4 and [Bpy]BF4 were employed as environmentally benign media in Doebner condensation to synthesize α, β-unsaturated carboxylic acid. The good results showed that [Bmim]BF4 and [Bpy]BF4 were efficient media for Doebner condensation, which could be recycled easily. The highest yields could reach 93% and 90% in [Bmim]BF4 and [Bpy]BF4, respectively.
文摘A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions can be used for the synthesis of drugs and biologically active organic compound of arsenic, antimony and bismuth. A possible new mechanism of the reaction is proposed.
文摘Sinapinic acid is a widespread compound in vegetable material and is as such common in the human diet. Recently it has drawn attention because of its biological activities. Sinapinic acid can be synthesized from syringaldehyde via the Knoevenagel-Doebner condensation. However this reaction is limited by the formation of 4-vinylsyringol after a second decarboxylation. To gain more detailed information about this reaction and to improve control over the formation of sinapinic acid, the concentration time history of syringaldehyde and the reaction products of this reaction have been monitored over time at different reaction temperatures. The formation of 4-vinylsyringol was found to be inhibited by performing the reaction at temperature below 80°C. This allows the reaction to be optimized for the production of sinapinic acid, with an optimal yield of 78% after 2.5 hours at 70°C.
基金This work was supported by the National NaturalScience Foundation of China （Nos. 30930107, 30973640）, the Key Project of Science and Technology of Shanghai （No. 09431901700）, the Major Special Project for the Creation of New Drugs （No. 2009ZX09301-011） and Shanghai Leading Academic Discipline Project （No. B906）.
文摘A mild and efficient Knoevenagel-Doebner reaction from malonic acid and a wide range of aldehydes was catalyzed by a catalytic system consisting offlalanine and 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU）, affording the corresponding （E）-a,fl-unsaturated carboxylic acids in good to excellent yields and with high stereoselectivity. The advantage of the method is that the reaction could proceed smoothly at ambient temperature so that it can tolerate a variety of functional groups and avoid unnecessary side reactions.
