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
The different interactions between a chemosensor, 1-（naphthalen-2-yl）-3-（6-nitrobenzothiazol-2-yl）-thiourea （1）, and F, acetate （AcO-）, Cl-, and Br- anions have been investigated theoretically at the B3LYP/6-3...The different interactions between a chemosensor, 1-（naphthalen-2-yl）-3-（6-nitrobenzothiazol-2-yl）-thiourea （1）, and F, acetate （AcO-）, Cl-, and Br- anions have been investigated theoretically at the B3LYP/6-31＋G（d,p） level with the basis set superposition error （BSSE） correction. It was found that the high selectivity of compound 1 for F- can be ascribed to the ability of the anion to deprotonate the N-H fragment of the host sensor, while the chemosensor also has a strong affinity for AcO- by virtue of the formation of a hydrogen-bonded complex. Intramolecular charge transfer （ICT） causes the colorimetric signaling of compound 1 after interaction with F-/AcO. A study of substituent effects suggested that the O/NH- and O/S-substituted derivatives are also expected to be promising candidates for chromogenic F3AcO chemosensors.展开更多
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.
基金supported by the Natural Science Foundation of Inner Mongolia Autonomous Region (2011ZD02)
文摘The different interactions between a chemosensor, 1-（naphthalen-2-yl）-3-（6-nitrobenzothiazol-2-yl）-thiourea （1）, and F, acetate （AcO-）, Cl-, and Br- anions have been investigated theoretically at the B3LYP/6-31＋G（d,p） level with the basis set superposition error （BSSE） correction. It was found that the high selectivity of compound 1 for F- can be ascribed to the ability of the anion to deprotonate the N-H fragment of the host sensor, while the chemosensor also has a strong affinity for AcO- by virtue of the formation of a hydrogen-bonded complex. Intramolecular charge transfer （ICT） causes the colorimetric signaling of compound 1 after interaction with F-/AcO. A study of substituent effects suggested that the O/NH- and O/S-substituted derivatives are also expected to be promising candidates for chromogenic F3AcO chemosensors.
