A series of novel N-（substituted benzyl）-3,5-bis（benzylidene）-4-piperidones 5a--50 were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolys...A series of novel N-（substituted benzyl）-3,5-bis（benzylidene）-4-piperidones 5a--50 were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolysis decarboxylation and aldol condensation. The structures were confirmed by 1↑H NMR, IR, MS techniques and elemental analysis. Assay-based antiproliferative activity study using leukemic cell lines K562 revealed that most of the title compounds have high effectiveness in inhibiting leukemia K562 cells proliferation, among which the compounds 5g （IC50=7.81 μg·mL^-1）, 5k （IC50=6.35μg·mL^-1）, 51 （IC50=7.20 μg·mL^-1）, and 50 （IC50=5.79 μg·mL^-1） have better inhibition activities than standard 5-fluorouracil （IC50=8.56 μg·mL^-1）.展开更多
Cross double Mannich reaction and tandem cyclization were achieved under iodine catalyzed conditions,yielding a series of highly substituted 4-piperidones.Among the possible diastereomers,only one diastereomer was iso...Cross double Mannich reaction and tandem cyclization were achieved under iodine catalyzed conditions,yielding a series of highly substituted 4-piperidones.Among the possible diastereomers,only one diastereomer was isolated,which could be ascribed to the chair-like transition state in six-membered ring,in which all of the hindered groups are located in the pseudoequatorial orientation.展开更多
A multicomponent double Mannich reaction of amines, aldehydes and ketones was efficiently catalyzed by molecular iodine, producing a series of 4-piperidones in a stereoselective way. A variety of amines, aldehydes and...A multicomponent double Mannich reaction of amines, aldehydes and ketones was efficiently catalyzed by molecular iodine, producing a series of 4-piperidones in a stereoselective way. A variety of amines, aldehydes and ketones were tolerated in this tandem process, including those with labile functinal groups. Further investigation of the reaction between alkyl-imines and ketones showed that imines from amines and ketones were formed in situ and isomerized to enamine in the presence of molecular iodine to accelerate the corresponding Mannich addition.展开更多
A novel and concise synthetic access to enantiopure chiral 2-aryl/alkyl substituted 4-piperidone has been demonstrated.This new route features two key steps:the highly diastereoselective conjugate addition of homochir...A novel and concise synthetic access to enantiopure chiral 2-aryl/alkyl substituted 4-piperidone has been demonstrated.This new route features two key steps:the highly diastereoselective conjugate addition of homochiral lithium amides to trans-β-substituted-α,β-unsaturated methyl esters guaranteed the enantiopurity at 2 position(de>19:1)and the intramolecular attacking of carbanions to methyl esters led to the formation of the piperidone ring.A wide range of substrates,including chiral2-aryl and 2-alkyl-4-piperidones,were successfully synthesized with modest to high yield.Moreover,some non-chiral3-substituted-4-piperidones were also synthesized with enhanced ring-formation yield,implicating the versatility of this method in construction of various piperidine rings.展开更多
文摘A series of novel N-（substituted benzyl）-3,5-bis（benzylidene）-4-piperidones 5a--50 were synthesized with substituted benzylamines as raw materials via a series of Michael addition, Dieckmann condensation, hydrolysis decarboxylation and aldol condensation. The structures were confirmed by 1↑H NMR, IR, MS techniques and elemental analysis. Assay-based antiproliferative activity study using leukemic cell lines K562 revealed that most of the title compounds have high effectiveness in inhibiting leukemia K562 cells proliferation, among which the compounds 5g （IC50=7.81 μg·mL^-1）, 5k （IC50=6.35μg·mL^-1）, 51 （IC50=7.20 μg·mL^-1）, and 50 （IC50=5.79 μg·mL^-1） have better inhibition activities than standard 5-fluorouracil （IC50=8.56 μg·mL^-1）.
基金NSFC(No21002079)and Project(No20096203120002)supported by the Ministry of Education of the People's Republic of ChinaTechnological Innovation Project(NosNWNU-KJCXGC-03-75 and NWNU-KJCXGC-03-64) of Northwest Normal University for supporting our research
文摘Cross double Mannich reaction and tandem cyclization were achieved under iodine catalyzed conditions,yielding a series of highly substituted 4-piperidones.Among the possible diastereomers,only one diastereomer was isolated,which could be ascribed to the chair-like transition state in six-membered ring,in which all of the hindered groups are located in the pseudoequatorial orientation.
文摘A multicomponent double Mannich reaction of amines, aldehydes and ketones was efficiently catalyzed by molecular iodine, producing a series of 4-piperidones in a stereoselective way. A variety of amines, aldehydes and ketones were tolerated in this tandem process, including those with labile functinal groups. Further investigation of the reaction between alkyl-imines and ketones showed that imines from amines and ketones were formed in situ and isomerized to enamine in the presence of molecular iodine to accelerate the corresponding Mannich addition.
基金CAS Key Laboratory of Synthetic Chemistry of Natural Substances (2008DP173071) for analysis support
文摘A novel and concise synthetic access to enantiopure chiral 2-aryl/alkyl substituted 4-piperidone has been demonstrated.This new route features two key steps:the highly diastereoselective conjugate addition of homochiral lithium amides to trans-β-substituted-α,β-unsaturated methyl esters guaranteed the enantiopurity at 2 position(de>19:1)and the intramolecular attacking of carbanions to methyl esters led to the formation of the piperidone ring.A wide range of substrates,including chiral2-aryl and 2-alkyl-4-piperidones,were successfully synthesized with modest to high yield.Moreover,some non-chiral3-substituted-4-piperidones were also synthesized with enhanced ring-formation yield,implicating the versatility of this method in construction of various piperidine rings.
