Synthesis and Chemistry of 4,5-Dimagnesioimidazole Dianions
作者:Ralf H.-J. Butz、Stephen D. Lindell
DOI:10.1021/jo0161680
日期:2002.4.1
procedure for the generation of 4,5-dimagnesioimidazoles is described. N-Protected 2-substituted 4,5-diiodoimidazoles were treated with i-PrMgCl (2.4 equiv) in THF at 0-5 degrees C. The resulting vicinal dianions reacted with electrophiles to give 4,5-disubstituted imidazoles in 27-71% yields.
The preparation of imidazolo[5,4-b]carbazole-4,10-quinones 9 is described. The key steps of the synthesis are selective halogen-metal exchanges on the imidazole 3 and subsequent addition to carbonyl groups of ethyl-3-formylindole-2-carboxylate 4.