A series of enantiomencally pure (4R,5R)-(-)-4-alkryloxy-5-[(1R,2dihydro-2(5H)-furanones (2) have been synthesized in excellent yields via asymmetric conjugateadditions of primary alcohols to (R)-(-)-5-[(1R,2S,5R)-men...A series of enantiomencally pure (4R,5R)-(-)-4-alkryloxy-5-[(1R,2dihydro-2(5H)-furanones (2) have been synthesized in excellent yields via asymmetric conjugateadditions of primary alcohols to (R)-(-)-5-[(1R,2S,5R)-menthyloxy]-2(5H)-furanone (1) in the presenceof a catalytic amount of sodium in DMF, which provides access to new multifunctional homochiralbuilding blocks, optically. pure (R) or (S)-2-alkyloxy- 1,4-butanediols (3).展开更多
The benzophenone-initiated photoaddition of N-methyl ammes 2 to the chiral synthon1 proceeds in a regiospecitlc and highlyr stereocontrolled thshion to give the C-C photoadductscontaining a ne\viy stereogenic center 3...The benzophenone-initiated photoaddition of N-methyl ammes 2 to the chiral synthon1 proceeds in a regiospecitlc and highlyr stereocontrolled thshion to give the C-C photoadductscontaining a ne\viy stereogenic center 3a-3c. The enantiomerically pure N-C photoadducts, aminobutenolides 5a-5c have been obtained from the enantioselective photoaddition of secondary cyclicammes 4 with the chiral synthon 1 under the same conditions.展开更多
Valuable chiral N-Boc-β-benzyl-β-amino acid was concisely synthesized via construction of chiral NBoc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation.All of the starting materials f...Valuable chiral N-Boc-β-benzyl-β-amino acid was concisely synthesized via construction of chiral NBoc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation.All of the starting materials for the synthesis of chiral N-Boc-β-benzyl-β-amino acid are cheap,and two-step short procedure make it easy for the rapid construction of various chiral β-arylmethyl-β-amino acids and important drugs,such as sitagliptin phosphate.展开更多
Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydro...Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydroxy 1 methylethyl) pyrrolidine was found to be the best ligand in asymmetric conjugate addition among the five ligands. The products were obtained with up to 70% ee . The configuration of the product was determined jointly by the substituents on the carbon of the hydroxy group and the nitrogen atom.展开更多
文摘A series of enantiomencally pure (4R,5R)-(-)-4-alkryloxy-5-[(1R,2dihydro-2(5H)-furanones (2) have been synthesized in excellent yields via asymmetric conjugateadditions of primary alcohols to (R)-(-)-5-[(1R,2S,5R)-menthyloxy]-2(5H)-furanone (1) in the presenceof a catalytic amount of sodium in DMF, which provides access to new multifunctional homochiralbuilding blocks, optically. pure (R) or (S)-2-alkyloxy- 1,4-butanediols (3).
文摘The benzophenone-initiated photoaddition of N-methyl ammes 2 to the chiral synthon1 proceeds in a regiospecitlc and highlyr stereocontrolled thshion to give the C-C photoadductscontaining a ne\viy stereogenic center 3a-3c. The enantiomerically pure N-C photoadducts, aminobutenolides 5a-5c have been obtained from the enantioselective photoaddition of secondary cyclicammes 4 with the chiral synthon 1 under the same conditions.
基金financial support for this study from the National Natural Science Foundation of China (No. 21472110)
文摘Valuable chiral N-Boc-β-benzyl-β-amino acid was concisely synthesized via construction of chiral NBoc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation.All of the starting materials for the synthesis of chiral N-Boc-β-benzyl-β-amino acid are cheap,and two-step short procedure make it easy for the rapid construction of various chiral β-arylmethyl-β-amino acids and important drugs,such as sitagliptin phosphate.
基金theNationalNaturalScienceFoundationofChina (No .2 9972 0 16andQTProgram ) theTeachingandResearchAwardProgramforOutstandingYoungTeachersinHigherEducationInstitutionsoftheMinistryofEducationofChina
文摘Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydroxy 1 methylethyl) pyrrolidine was found to be the best ligand in asymmetric conjugate addition among the five ligands. The products were obtained with up to 70% ee . The configuration of the product was determined jointly by the substituents on the carbon of the hydroxy group and the nitrogen atom.
