Enediynes undergo intramolecular [2 + 2 + 2] cycloaddition in the presence of cobalt(II) iodide (CoI 2 ), manganese and an N-heterocyclic carbene (IPr) generated in situ from the corresponding imidazolium salt and butyllithium (BuLi). Polycyclic cyclohexadienes are obtained selectively. This new method represents an interesting alternative to those employing air-sensitive cyclopentadi-Moreover, the N-heterocyclic carbene can be used catalytically, which is a significant improvement compared to the corresponding phosphine-based system which requires an excess of ligand.
Cycloaddition reactions O 0070A Straightforward Procedure for the [2 + 2 + 2] Cycloaddition of Enediynes. -In the presence of stoichiometric amounts of cobalt iodide and manganese, and a catalytic amount of carbene IPr, the enediynes are chemoselectively transformed into polycyclic fused 1,3-cyclohexadienes. -(GENY, A.; GAUDREL, S.; SLOWINSKI, F.; AMATORE, M.; CHOURAQUI, G.; MALACRIA, M.; AUBERT*, C.; GANDON, V.; Adv. Synth. Catal. 351 (2009) 1-2, 271-275; Lab. Chim. Org., CNRS, Univ. P. et M. Curie, F-75252 Paris, Fr.; Eng.) -Klein 23-037
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.