Vinyl bromides derivedfrom 2-alkylidene-4-oxothiazolidines represent a class of vinyl halides, which readily undergo a bromophilic attack by a range of nucleophiles. With Ph3P, AcS−, CN−, I−, F−, Ac2CH− and N3− the attack ends up with reductive debromination, whereas the bromine substitution takes place with KSCN. When acetate anion and organic bases, such as pyridine, Et3N or morpholine, are employed
A facile access to thiazolidin-4-ones from α-enolic dithioesters and α-halohydroxamates in situ derived active 1,3-dipolar aza-oxyallyl cations was achieved under mild conditions.
Regioselective synthesis of 1,3-thiazines by sequential 4-oxothiazolidine to 1,2-dithiole to 1,3-thiazine transformations: role of intramolecular non-bonded S⋯O interactions
作者:Aleksandar Rašović、Peter J. Steel、Erich Kleinpeter、Rade Marković
DOI:10.1016/j.tet.2006.12.075
日期:2007.2
A new synthetic approach to 2,3-dihydro-4H-1,3-thiazine derivatives based upon reductive rearrangement of 1,2-dithiole-3-ylidene thiones has been developed. In turn, the 1,2-dithiole derivatives were prepared by an efficient ring-opening-c losing process of 2-alkylidene-4-oxothiazolidines, induced in the presence of Lawesson's reagent by intramolecular non-bonded 1,5-type (SO)-O-... interactions in the 4-oxothiazolidine precursors. (c) 2007 Elsevier Ltd. All rights reserved.
π-Annulation reactions of 4-thiazolidinone enaminones in the synthesis of fused bi- and tri-cyclic compounds
作者:Bojan P. Bondžić、Zdravko Džambaski、Aleksandra M. Bondžić、Rade Marković
DOI:10.1016/j.tet.2012.09.080
日期:2012.11
reactivity of α-C of the exocyclic double bond (a so called push pull system) to obtain bicyclic fused thiazolidinones via π-annulation cyclization. Appropriate reaction conditions to selectively activate this position and secondary nitrogen towards N,π-annulation were found. Furthermore, the intramolecular vinylogous iminium ion 6-exo-trig cyclization was used to access fused bicyclic precursors for the
A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR spectroscopy and DFT theoretical calculations. It was found that the thermodynamically less stable anti-isomer was initially formed in the course of the oxidation, but it underwent epimerization