Unexpected C–C Bond Cleavage: A Route to 3,6-Diarylpyridazines and 6-Arylpyridazin-3-ones from 1,3-Dicarbonyl Compounds and Methyl Ketones
摘要:
An unexpected C-C bond cleavage has been revealed in the absence of metal. This observation has been exploited to develop an efficient approach toward 3,6-iarylpyridazines and 6-arylpyridazin-3-ones from simple and commercially available 1,3-dicarbonyl compounds and methyl ketones.
Transition metal complexes of N-heterocyclic carbenes, method of preparation and use in transition metal catalyzed organic transformations
申请人:Organ G. Michael
公开号:US20070073055A1
公开(公告)日:2007-03-29
The present invention relates to catalysts of transition metal complexes of N-heterocyclic carbenes, their methods of preparation and their use in chemical synthesis. The synthesis, ease-of-use, and activity of the compounds of the present invention are substantial improvements over in situ catalyst generation. Further, the transition metal complexes of N-heterocyclic carbenes of the present invention may be used as precatalysts in metal-catalyzed cross-coupling reactions.
A User-Friendly, All-Purpose Pd–NHC (NHC=N-Heterocyclic Carbene) Precatalyst for the Negishi Reaction: A Step Towards a Universal Cross-Coupling Catalyst
作者:Michael G. Organ、Stephanie Avola、Igor Dubovyk、Niloufar Hadei、Eric Assen B. Kantchev、Christopher J. O'Brien、Cory Valente
DOI:10.1002/chem.200600206
日期:2006.6.14
We have developed the first user-friendly Negishi protocol capable of routinely cross-coupling all combinations of alkyl and aryl centers. The use of an easily synthesized, air stable, highly active, well-defined precatalyst PEPPSI-IPr (1; PEPPSI=pyridine-enhanced precatalyst preparation, stabilization and initiation; IPr=diisopropylphenylimidazolium derivative) substantially increases the scope, reliability
Simple, commercially available iodine was successfully employed as a highly efficient and chemoselective catalyst for the oxidative annulation of β,γ-unsaturatedhydrazones to produce 1,6-dihydropyridazines under mild conditions for the first time. Interestingly, when active β,γ-unsaturatedhydrazone compounds containing electron-donating groups, such as furyl, thienyl, and cycloalkyl, were used, pyrroles