Categories: C=C Bond Formation >

Reductive alkene formations

Name Reactions

Corey-Winter Olefin Synthesis

Julia-Lythgoe Olefination

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Recent Literature

A highly stereoselective synthesis of aromatic α,β-unsaturated amides was achieved by treatment of aromatic α,β-epoxyamides with samarium diiodide. α,β-epoxyamides are easily prepared by the reaction of enolates derived from α-chloroamides with carbonyl compounds at -78°C.
J. M. Concellón, E. Bardales, J. Org. Chem., 2003, 5, 9492-9295.

The ionic liquid 1-methyl-3-pentylimidazolium fluoroborate, [pmIm]BF₄, is an efficient catalyst as well as solvent for the stereoselective debromination of various vicinal-dibromides to the corresponding (E)-alkenes in high yields under microwave irradiation. This reaction does not require any conventional reducing agent, and the ionic liquid can be recycled.
B. C. Ranu, R. Jana, J. Org. Chem., 2005, 70, 8621-8624.

Dichloroindium hydride (Cl₂InH) generated in situ from the combination of a catalytic amount of indium(III) chloride and sodium borohydride in acetonitrile reduces activated vic-dibromides to the corresponding (E)-alkenes in excellent yields.
B. C. Ranu, A. Das, A. Hajira, Synthesis, 2003, 1012-1014.

Dimethyl sulfoxide efficiently causes the reductive elimination of 3-aryl 2,3-dibromopropanoates to cinnamates with good yield. For most substrates debromination is the major pathway, whereas dehydrobromination is a competing pathway with thiophene derivatives. ¹H NMR, ⁸¹Br NMR, and MS indicated the formation of brominated-DMSO, MeBr, and HBr as byproducts.
W. Li, J. Li, M. Lin, S. Wacharasindhu, K. Tabei, T. S. Mansour, J. Org. Chem., 2007, 72, 6016-6021.

The use of SmI₂ in the reductive elimination of 1,2-acetoxy sulfones (Julia-Lythgoe olefination) and the reductive cleavage of vinyl sulfones is reported.
G. E. Keck, K. A. Savin, M. Weglarz, J. Org. Chem., 1995, 60, 3194-3204.

Stereoselective β-elimination of diastereomeric mixtures of 2-bromo-3-hydroxy­esters is achieved by using unactivated manganese and trimethylsilyl chloride, to yield (E)-α,β-unsaturated esters with total diastereoselectivity.
J. M. Concellón, H. Rodríguez-Solla, V. del Amo, Synlett, 2006, 315-317.

Samarium diiodide promotes a photoinduced metalation of nonactivated C-Cl bonds of O-acetyl chlorohydrins and a β-elimination which affords alkenes with total or high stereoselectivity.
J. M. Concellon, H. Rodriguez-Solla, C. Simal, M. Huerta, Org. Lett., 2005, 7, 5833-5835.