TY  - JOUR
A1  - Stojanovic, Milovan
A1  - Markovic, Rade
A1  - Kleinpeter, Erich
A1  - Baranac-Stojanovic, Marija
T1  - Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions
T2  - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry
N2  - Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed. Instead, the bicyclic (5,6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic control, whereas the formation of the eight-membered ring was kinetically controlled.
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/36400
SN  - 1477-0520
VL  - 10
IS  - 3
SP  - 575
EP  - 589
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -