TY  - JOUR
AU  - Lázár, László
AU  - Kivela, H
AU  - Pihlaja, K
AU  - Fülöp, Ferenc
TI  - A convenient and highly stereoselective synthesis of 14-substituted 8,13-diazaoestrone analogues by domino ring closures
JF  - TETRAHEDRON LETTERS
J2  - TETRAHEDRON LETT
VL  - 45
PY  - 2004
SP  - 6199
EP  - 6201
PG  - 3
SN  - 0040-4039
DO  - 10.1016/j.tetlet.2004.05.054
UR  - https://m2.mtmt.hu/api/publication/1013243
ID  - 1013243
N1  - Inst. of Pharmaceutical Chemistry, University of Szeged, H-6701 POB 121, Szeged, Hungary            
            Department of Chemistry, Structural Chemistry Group, University of Turku, FIN-20014, Turku, Finland            
            Cited By :11            
            Export Date: 20 May 2023            
            CODEN: TELEA            
            Correspondence Address: Fülöp, F.; Inst. of Pharmaceutical Chemistry, , Szeged, Hungary; email: fulop@pharma.szote.u-szeged.hu            
            Funding details: Hungarian Scientific Research Fund, OTKA, TS40888            
            Funding text 1: Financial support from the Hungarian Research Foundation (OTKA No TS40888), as well as Hungarian State Eötvös Fellowship (Hungarian Scholarship Board) to L.L. is acknowledged.
AB  - By means of convenient domino ring closure reactions of 1-(2-aminoethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 2 and 7-oxo-acids, 14-substituted 8,13-diazaoestrone derivatives (5 and 6) were formed with similar to100% diastereoselectivity. (C) 2004 Elsevier Ltd. All rights reserved.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Hetényi, Anasztázia
AU  - Martinek, Tamás
AU  - Lázár, László
AU  - Zalán, Zita
AU  - Fülöp, Ferenc
TI  - Substituent-dependent negative hyperconjugation in 2-aryl-1,3-N,N-heterocycles. Fine-tuned anomeric effect?
JF  - JOURNAL OF ORGANIC CHEMISTRY
J2  - J ORG CHEM
VL  - 68
PY  - 2003
IS  - 14
SP  - 5705
EP  - 5712
PG  - 8
SN  - 0022-3263
DO  - 10.1021/jo034417+
UR  - https://m2.mtmt.hu/api/publication/1013527
ID  - 1013527
AB  - The epimerization reactions of conformationally inflexible 2-aryl-1,3-N,N-heterocycles were used as model systems to study the role of the nitrogen lone pair-C2 associated antibonding orbital hyperconjugative interactions in the experimentally observed substituent-dependent generalized anomeric effect. The measured reaction free enthalpies were found to correlate well with the sum of the hyperconjugative stabilization energies of all the vicinal donor-acceptor orbital overlaps around C2, obtained from ab initio NBO analysis, and both quantities correlated linearly with the Hammett-Brown substituent constant. The individual stereoelectronic interactions (n(N)-sigma*(C2-N), n(N)-sigma*(C2-Ar), n(N-sigma)*(C2-H)) were also observed to exhibit a substituent dependence, despite their distance from the 2-aryl substituent and their nonperiplanar arrangement. The higher the electron-withdrawing effect of the 2-aryl substituent, the larger was the stabilization for n(N)-sigma*(C2-Ar), while the overlaps n(N)-sigma*(C2-N) and n(N)-sigma*(C2-H) changed in the opposite sense. The different polarization of the acceptor sigma* orbitals, caused by the 2-aryl substituent, accounted for the observed propagation of the substituent effect. These results promote a detailed explanation of the useful tautomeric behavior of the 2-aryl-1,3-X,N-heterocycles, and reveal the nature of the connection between the anomeric effect and the Hammett-type linear free energy relationship.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Zalán, Zita
AU  - Martinek, Tamás
AU  - Lázár, László
AU  - Fülöp, Ferenc
TI  - Synthesis and conformational analysis of 1,3,2-diazaphosphorino[6,1-a]isoquinolines, a new ring system
JF  - TETRAHEDRON
J2  - TETRAHEDRON
VL  - 59
PY  - 2003
SP  - 9117
EP  - 9125
PG  - 9
SN  - 0040-4020
DO  - 10.1016/j.tet.2003.09.062
UR  - https://m2.mtmt.hu/api/publication/1013518
ID  - 1013518
N1  - CAplus AN 2003:841978 (Journal);
AB  - Through ring-closure reactions of N- or V-substituted 1-(2'-aminoethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (5a-e) with phenylphosphonyl dichloride, 1- or 3-substituted 4-phenyl-1,3,4,6,7,11b-tetrahydro-2H-1,3,2-diazaphosphorino[6,1-a]isoqui nolin-4-one diastereomers (7a-e and 8a-c,e), the first representatives of a new ring system, were prepared. The diastereomeric ratios in the cyclizations and the conformer (A-E) populations of the nitrogen-bridged tricyclic systems (7 and 8) were strongly influenced by the N- and 1'-substituents of the starting diamines. The conformational analysis of compounds 7 and 8 was performed by H-1, C-13 and P-31 NMR methods. (C) 2003 Elsevier Ltd. All rights reserved.
LA  - English
DB  - MTMT
ER  -