The intramolecular cycloizomerization of 2-alkynyl-3-nitrothiophenes was catalyzed by AuCl3 or CF3CO2Ag to produce the corresponding thieno[3,2-c]isoxazoles bearing carbonyl functionality in position 3 instead of expected 5-substituted 6H-thieno[3,2-b]pyrrol-6-one 4-oxides.
Intramolecular Iodine-Mediated Oxygen Transfer from Nitro Groups to C≡C Bonds
作者:Inga Cikotiene
DOI:10.1002/ejoc.201200100
日期:2012.5
from nitrogroups to C≡C bonds has been achieved by employment of iodine monochloride or molecular iodine. The precursors are heterocyclic, aromatic or acyclic compounds, each bearing a nitrogroup ortho to an internal alkyne. The developed methodology is general for the preparation of a wide range of fused isoxazoles, each bearing a carbonyl function in the fifth position in the isoxazole ring. It