Diethylzinc: A Chain-Transfer Agent in Intermolecular Radical Additions. A Parallel with Triethylborane
摘要:
In the presence of oxygen, diethylzinc can be used to promote radical additions to C=N bond containing radical accepters and to enones. In these reactions, it plays at the same time the role of the initiator and the role of the chain-transfer reagent. A parallel with triethylborane-mediated reactions is established. The methodology is restricted to secondary and tertiaryalkyl radicals generated from the corresponding alkyl iodides. It could not be extended either to C=C bond containing radical accepters such as methyl methacrylate and nitrocyclohexene or to diethylazodicarboxylate.
Evaluation of phenylorganotellurium compounds as radical precursors in dialkylzinc-mediated radical addition to CN double bonds
作者:Fabien Cougnon、Laurence Feray、Samantha Bazin、Michèle P. Bertrand
DOI:10.1016/j.tet.2007.09.014
日期:2007.11
Diethylzinc-mediated radical addition to CNbonds was investigated in the presence of phenylorganotellurium compounds as radical precursors. As group transfer agents, secondary alkyl phenyl tellurides were shown to be about twice as reactive as the corresponding alkyl iodides towards ethyl radical. Their use was proven to be advantageous regarding both chemoselectivity and yield. The replacement of