60026-93-9Relevant academic research and scientific papers
1,3-Dipolar cycloadditions of new mesoionic compounds. Synthesis of 1H-pyrrolo[1,2-c]thiazoles, pyrrolizines and 5,6,7,8-tetrahydroindolizines
Dalla Croce, Piero,La Rosa, Concetta
, p. 1843 - 1857 (2007/10/03)
We studied the 1,3-dipolar cycloaddition reactions between alkyne dipolarophiles and the new mesoionic compounds 2H,5H,7H-thiazolo[4,3-b]oxazol-2-one (12), 2H,5H,7H-pyrrolo[2,1-b]oxazol-2-one (13) and 2H,5H,7H-oxazolo[3,2-a]pyridin-2-one (14). These 1,3-dipoles were prepared in situ by means of cyclodehydration with acetic anhydride of the corresponding α-substituted 4-oxo-3-thiazolidine- (9), 2-oxo-1-pyrrolidine- (10) and 2-oxo-1-piperidineacetic acids (11). The cycloaddition reactions with alkyne dipolarophiles afforded single 1H-pyrrolo[1,2-c]thiazole, pyrrolizine and 5,6,7,8-tetrahydroindolizine derivatives, or a mixture of the two possible regioisomers, depending on whether symmetrical or unsymmetrical alkynes.
RHODIUM(II) CATALYZED CYCLIZATION OF DIAZO THIOCARBONYL COMPOUNDS FOR HETEROCYCLIC SYNTHESIS
Padwa, Albert,Kinder, Frederic R.,Nadler, William R.,Zhi, Lin
, p. 367 - 383 (2007/10/02)
The mesoionic thioisomuenchnone system was prepared from the rhodium(II) acetate catalyzed cyclization of a diazothioamide and was found to undergo smooth 1,3-dipolar cycloaddition with N-phenylmaleimide.In contrast to this system, the rhodium(II) reaction of α-diazo-β-oxo ester containing a thiocarbonyl group produced a cyclic thiocarbonyl ylide which extruded sulfur from a transient episulfide intermediate.
THE USE OF N-ETHYL-N'-DIMETHYLAMINOPROPYLCARBODIIMIDE OR SILICON TETRACHLORIDE IN PYRROLE SYNTHESES.
Anderson, Wayne K.,Heider, Arvela R.
, p. 357 - 364 (2007/10/02)
Two methods are used for mesoionic oxazolone formation in the synthesis of pyrroles in 1,3-dipolar cycloaddition reactions.N-ethyl-N'-dimethylaminopropylcarbodiimide or silicon tetrachloride are used to activate the N-acylamino acid.
