Synthesis of 4-aryl-substituted β-lactam enantiomers by enzyme-catalyzed kinetic resolution
摘要:
Enantiopure 4-phenyl- and 4-(p-tolyl)-2-azetidinones 3a, 3b, 4a and 4b (with e.e.s of greater than or equal to 96%) were prepared through lipase-catalyzed asymmetric butyrylation of the primary OH group of N-hydroxymethylated beta -lactams (+/-)-5 and (+/-)-6 at the (R)-stereogenic centre or by lipase-catalyzed asymmetric debutyrylation of O-butyryloxymethyl-2-azetidinones (+/-)-7 and (+/-)-8 at the (R)-stereogenic centre. The ring-opening of lactams 5a. 5b, 6b and 8a with HCl/EtOH afforded the corresponding P-amino ester enantiomers 9a, 9b, 10a and 10b with e.e.s or greater than or equal to 92%, (C) 2001 Elsevier Science Ltd. All rights reserved.
Molecular Basis for the Enantioselective Ring Opening ofβ-Lactams Catalyzed byCandida antarctica Lipase B
作者:Seongsoon Park、Enikö Forró、Harjap Grewal、Ferenc Fülöp、Romas J. Kazlauskas
DOI:10.1002/adsc.200303069
日期:2003.8
yielded the unreacted β-lactam in 39–46% yield (maximum yield is 50%) with ≥96% ee. The product β-amino acid esters reacted further by polymerization (not isolated or characterized) or by hydrolysis due to small amounts of water in the reaction mixture yielding β-amino acids (7–11% yield, ≥96% ee). The favored enantiomer of all four β-lactams had similar 3-D orientation of substituents, as did most previously
Comparison of separation performances of amylose- and cellulose-based stationary phases in the high-performance liquid chromatographic enantioseparation of stereoisomers of β-lactams
High‐performanceliquidchromatographic methods were developed for the separation of the enantiomers of 19 β‐lactams. The direct separations were performed on chiral stationaryphases containing either amylose‐tris‐3,5‐dimethylphenyl carbamate, (Kromasil® AmyCoat™ column) or cellulose‐tris‐3,5‐dimethylphenyl carbamate, (Kromasil® CelluCoat™ column) as chiral selector. The different methods were compared
Site-selective enzymatic C‒H amidation for synthesis of diverse lactams
作者:Inha Cho、Zhi-Jun Jia、Frances H. Arnold
DOI:10.1126/science.aaw9068
日期:2019.5.10
rings of varying size (see the Perspective by Hepworth and Flitsch). The enzyme directs amidation to the desired position and simultaneously prevents other side reactions. Science, this issue p. 575; see also p. 529 Evolved enzymes selectively form β-, γ-, and δ-lactams from simple precursors. A major challenge in carbon‒hydrogen (C‒H) bond functionalization is to have the catalyst control precisely where
Stereoselective construction of β-, γ- and δ-lactam rings via enzymatic C–H amidation
作者:Satyajit Roy、David A. Vargas、Pengchen Ma、Arkajyoti Sengupta、Ledong Zhu、K. N. Houk、Rudi Fasan
DOI:10.1038/s41929-023-01068-2
日期:——
are found in many biologically active natural products and pharmaceuticals, including important classes of antibiotics. Methods for the asymmetric synthesis of these molecules are therefore highly desirable, particularly through the selective functionalization of unreactive aliphatic C–H bonds. Here we show the development of a strategy for the asymmetric synthesis of β-, γ- and δ-lactams via the haemoprotein-catalysed
Synthesis of 4-aryl-substituted β-lactam enantiomers by enzyme-catalyzed kinetic resolution
作者:Enikő Forró、Ferenc Fülöp
DOI:10.1016/s0957-4166(01)00388-3
日期:2001.9
Enantiopure 4-phenyl- and 4-(p-tolyl)-2-azetidinones 3a, 3b, 4a and 4b (with e.e.s of greater than or equal to 96%) were prepared through lipase-catalyzed asymmetric butyrylation of the primary OH group of N-hydroxymethylated beta -lactams (+/-)-5 and (+/-)-6 at the (R)-stereogenic centre or by lipase-catalyzed asymmetric debutyrylation of O-butyryloxymethyl-2-azetidinones (+/-)-7 and (+/-)-8 at the (R)-stereogenic centre. The ring-opening of lactams 5a. 5b, 6b and 8a with HCl/EtOH afforded the corresponding P-amino ester enantiomers 9a, 9b, 10a and 10b with e.e.s or greater than or equal to 92%, (C) 2001 Elsevier Science Ltd. All rights reserved.