Asymmetric synthesis of novel 1,4-aminoalcohol ligands with norbornene and norbornane backbone: use in the asymmetric diethylzinc addition to benzaldehyde

2007-09-27
Tanyeli, Cihangir
ERDEM, Mine
ÇAKIR, Esen
KESKİN, Eda
The asymmetric synthesis of cis-1,4-aminoalcohols with norbornene and norbornane backbone was performed starting with (2S, 3R)-(-)-cis-hemiester 1 (98% ee). Chemoselective amination with HMPTA followed by Grignard reactions and subsequent LAH reductions afforded compounds 5a-d. cis-Hemiester 1 was also transformed into chiral ligands 7a-f and 9a-d with the DCC coupling method followed by LAH reduction using acyclic, heterocyclic amines and various aniline derivatives and p-toluenesulfonamide, respectively. The chiral ligands were subjected to asymmetric diethylzinc addition to examine their effectiveness as chiral catalysts. Among these, arylamine and tosyl substituted chiral ligands 9a-d exhibited the highest selectivities (up to 97% ee).
TETRAHEDRON-ASYMMETRY

Suggestions

Asymmetric synthesis of 1,4-amino alcohol ligands with a norbornene backbone for use in the asymmetric diethylzinc addition to benzaldehyde
Tanyeli, Cihangir (Elsevier BV, 2005-06-06)
The asymmetric synthesis of cis-1,4-amino alcohols with a norbornene backbone was performed starting with (2S,3R)(-)-cis-hemiester 2 (98% ee). Chemoselective amination with NH4OH and HMPTA followed by LAH reduction afforded 5 and 7. respectively. Amido ester 6 was transformed into chiral ligand 9 with Grignard reaction followed by LAH reduction. The chiral ligands 5. 7. and 9 were subjected to asymmetric diethylzinc addition to examine their effectiveness as chiral catalysts. Among these, c chiral ligand 7 ...
Enantioselective synthesis of both enantiomers of 2-amino-2-(2-furyl)ethan-1-ol as a flexible building block for the preparation of serine and azasugars
Demir, Ayhan Sıtkı; Sesenoglu, O; Aksoy-Cam, H; Kaya, H; Aydogan, K (Elsevier BV, 2003-05-16)
The selective conversion of 1-(2-furyl)-2-hydroxyethan-1-one and ethyl 2-(2-furyl)-2-oxo acetate into (E)- and (Z)-oximes and oxime ethers followed by oxazaborolidine-catalyzed enantioselective reduction using different amino alcohols furnished both enantiomers of the important chiral building block 2-amino-2-(2-furyl)ethan-1-ol with an ee of up to 96%.
Asymmetric synthesis of norbornene based 1,4-amino alcohol derivatives and applications in asymmetric transformations
Sünbül, Murat; Tanyeli, Cihangir; Department of Chemistry (2005)
The asymmetric synthesis of cis-1,4-aminoalcohols with norbornene backbone was performed starting with simple and cheap anhydride 30. Quinine-mediated desymmetrization of anhydride 30 with methanol resulted in (2S,3R)-(-)-cis-hemiester 31 (98% e.e.). Chemoselective amination with HMPTA and NH4OH followed by LAH reduction afforded (2S,3R)-(+)-36 and (2S,3R)-(-)-37, respectively. The amidoester (2S,3R)-(-)-32 was transformed into chiral ligand (2S,3R)-(-)-35 with Grignard reaction followed by LAH reduction. T...
Asymmetric synthesis and molecular docking study of enantiomerically pure pyrrolidine derivatives with potential antithrombin activity
Ayan, Seylan; Doğan, Özdemir; Ivantcova, Polina M.; Datsuk, Nikita G.; Shulga, Dmitry A.; Chupakhin, Vladimir I.; Zabolotnev, Dmitry V.; Kudryavtsev, Konstantin V. (Elsevier BV, 2013-07-31)
The (2R,4R,5S)- and (2S,4S,5R)-enantiomers of 4-(tert-butyl) 2-methyl 5-(4-bromophenyl)-pyrrolidine-2,4-dicarboxylate 3 were synthesized efficiently with an ee of >90% on a gram scale using a FAM-catalytic methodology. Subsequent modification afforded enantiopure N-((4-chlorophenyl)thio)acetyl pyrrolidine derivatives 4, which are potential thrombin inhibitors according to comprehensive molecular docking studies.
Enantioselective synthesis of 2-(2-arylcyclopropyl)glycines: Conformationally restricted homophenylalanine analogs
Demir, Ayhan Sıtkı; Sesenoglu, O; Ulku, D; Arici, C (Wiley, 2004-01-01)
Starting from simple aromatic aldehydes and acetylfuran, (E)-1-(furan-2-yl)-3-arylprop-2-en-1-ones (2) were synthesized in high yields. Cyclopropanation of the C=C bond with trimethylsulfoxonium iodide (Me3SO+I-) furnished (furan-2-yl)(2-arylcyclopropyl)methanones 3 in 90-97% yields. Selective conversion of cyclopropyl ketones to their (E)- and (Z)-oxime ethers 5 and oxazaborolidine-catalyzed stercoselective reduction of the C-N bond followed by separation of the formed diastereoisomers, furnished (2-arylcy...
Citation Formats
C. Tanyeli, M. ERDEM, E. ÇAKIR, and E. KESKİN, “Asymmetric synthesis of novel 1,4-aminoalcohol ligands with norbornene and norbornane backbone: use in the asymmetric diethylzinc addition to benzaldehyde,” TETRAHEDRON-ASYMMETRY, pp. 2349–2357, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40171.