Amination/annulation of chlorobutenones with chiral amine compounds: synthesis of 1,2,4-trisubstituted pyrroles

Demir, Ayhan Sıtkı
Igdir, AC
Gunay, NB
A series of 1,2,4-trisubstituted pyrroles have been synthesized in 83-96% yields on treatment of chiral primary amines, amino alcohols and esters of alpha-amino acids with different chlorobutenones in benzene-triethylamine. The conversions proceed without racemization.


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%.
Functionalization of oxabenzonorbornadiene: Manganese(III)-mediated oxidative addition of dimedone
ÇALIŞKAN, Raşit; Sari, Ozlem; Balcı, Metin (Wiley, 2017-09-01)
3-Chloro-1,2,3,4-tetrahydro-1,4-epoxynaphthalen-2-yl)-3-hydroxy-5,5-dimethylcy-clohex- 2-en-1-one, synthesized by the reaction of oxabenzonorbornadiene with Mn(OAc)(3) and dimedone in the presence of HCl in acetic acid, was submitted to ring-opening reactions with BBr3 and H2SO4. Reaction with BBr3 yielded 2 products, a 5-membered ring and an 8-membered ring, with the former being the major product. However, the H2SO4-supported reaction exclusively formed an 8-membered ring. The mechanism of formation of th...
Chemoenzymatic synthesis of alpha(1)- and alpha-acetoxylated cyclic ketones
Tanyeli, Cihangir; Akhmedov, M (Elsevier BV, 2004-06-07)
alpha,beta-Unsaturated and saturated cyclic ketones were selectively oxidized at the alpha'- and alpha-positions using Mn(OAc)(3) and Pb(OAc)(4), respectively, resulting in high chemical yields. The resultant racemic alpha'- and alpha-acetoxylated substrates were resolved into corresponding enantiomerically enriched alpha'- and alpha-hydroxylated and acetoxylated compounds with 96-98% ee via PLE hydrolysis. The absolute configurations of alpha'-acetoxy-alpha,beta-unsaturated cyclic ketones were determined b...
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 ...
Novel enantioselective synthesis of both enantiomers of furan-2-yl Amines and amino acids
Demir, Ayhan Sıtkı; Sesemoglu, O; Ulku, D; Arici, C (Wiley, 2003-01-01)
A new enantioselective synthesis of furan-2-yl amines and amino acids is described, in which the key step is the oxazaborolidine-catalyzed enantioselective reduction of O-benzyl (E)- and (Z)-furan-2-yl ketone oximes to the corresponding chiral amines. The chirality of the furan-2-yl amines is fully controlled by the appropriate choice of the geometrical isomer of the O-benzyl oxime. Oxidation of the furan ring furnished amino acids in high yields.
Citation Formats
A. S. Demir, A. Igdir, and N. Gunay, “Amination/annulation of chlorobutenones with chiral amine compounds: synthesis of 1,2,4-trisubstituted pyrroles,” TETRAHEDRON-ASYMMETRY, pp. 3170–3175, 2005, Accessed: 00, 2020. [Online]. Available: