90304-05-5Relevant academic research and scientific papers
(3S,4S)-N-substituted-3,4-dihydroxypyrrolidines as ligands for the enantioselective Henry reaction
Rénio, Márcia R.R.,Sousa, Francisco J.P.M.,Tavares, Nélia C.T.,Valente, Artur J.M.,da Silva Serra, M. Elisa,Murtinho, Dina
, (2021/02/03)
The enantioselective Henry reaction is a very important and useful carbon–carbon bond forming reaction. The execution of this reaction requires the use of efficient chiral catalysts. In this work, in situ formed complexes of N-substituted dihydroxypyrrolidines, chiral ligands derived from L-tartaric acid and amines, were evaluated as catalysts in the enantioselective Henry reaction. The results showed that the nature of the N-substituent on the ligand significantly influences the outcome of the reaction. Best results were obtained using a Cu (II) complex of (3S,4S)-N-benzyl-3,4-dihydroxypyrrolidine, in the presence of DIPEA, for the reaction of aromatic aldehydes with nitromethane, at room temperature, originating products with er up to 92:8 (R:S) and conversions up to 96%. The interaction between the pyrrolidine ligand and the copper ion, in isopropanol, was followed by UV-vis spectrophotometry, showing a 1:1 stoichiometry and a binding constant of 4.4. The results obtained will contribute to the design and development of more efficient chiral catalysts for this type of reaction.
Enantioselective syntheses of trans-3,4-difluoropyrrolidines and investigation of their applications in catalytic asymmetric synthesis
Marson, Charles M.,Melling, Robert C.
, p. 9771 - 9779 (2007/10/03)
Asymmetric syntheses of enantiopure trans-3,4-difluoropyrrolidines have been prepared by the introduction of fluorine at both centers in a single operation; asymmetric epoxidations and additions to benzaldehyde were conducted using catalysts whose chirality depends on organofluorine asymmetry.
The first enantioselective syntheses of vicinal difluoropyrrolidines and the first catalytic asymmetric synthesis mediated by the C2 symmetry of a -CHFCHF- Unit
Marson, Charles M.,Melling, Robert C.
, p. 1223 - 1224 (2007/10/03)
The first enantiopure vicinal difluorides of C2 symmetry have been prepared by the introduction of fluorine at both centres in a single operation; the first asymmetric synthesis using a catalyst whose chirality depends on organofluorine asymmetry is described.
