New applications of transition metal-based single electron reducing agents in organic synthesis: Samarium diiodide-promoted beta-elimination reactions

ORGN 114

Jose M. Concellón, Humberto Rodriguez-Solla,, Carmen Concellón, Carmen Simal, and Pamela Díaz. Organic and Inorganic Department, University of Oviedo, Julian Claveria, 8, Oviedo, 33071, Spain
We describe an efficient and highly diastereoselective preparation of alkenes from O-acetylated chlorohydrines, in which the b-elimination reaction is initiated by metalation of non-activated C-Cl bonds by samarium diiodide in the presence of visible light. To the best of our knowledge, this is the first methodology to promote 1,2 elimination processes by treatment of chlorinated compounds, in which the C-Cl bond is not activated, with SmI2.

Also, we previously reported the synthesis of a,b-unsaturated ketones with total or high diastereoselectivity through a b-elimination process by reaction of a-chloro-b-hydroxy ketones with samarium diiodide or triiodide. Here, we show our results in the diastereoselective synthesis of (E)-a,b-unsaturated ketones by a sequential reaction of dichloroketone and aldehydes with samarium diiodide.