Synthesis of N-substituted 2,4-thiazolidinediones from oxazolidinethiones
摘要:
A novel reaction has been found between oxazolidinethione and bromoacetyl bromide to afford N-substituted 2,4-thiazolidinediones through an intramolecular nucleophilic substitution reaction. Interestingly a step of elimination was carried out in trisubstituted oxazolidinethiones forming a double bond. (c) 2005 Elsevier Ltd. All rights reserved.
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed
NbCl5 has been employed as promoter of a novelrearrangement to afford chiral N-substituted 1,3-thiazine-2,4-diones with one or two new stereogenic centers from di- and trisubstituted N-enoyl oxazolidinethiones. The trisubstituted E-isomers provide the anti-diastereomers mainly.