Categories: C=C Bond Formation >
Reductive alkene formations
Name Reactions
Recent Literature
Electrolysis using an undivided cell fitted with a pair of zinc electrodes in a
mixture of saturated aqueous NH4Br and tetrahydrofuran enables an
efficient synthesis of alkenes from epoxides. The reaction is mediated by Zn(0)
with a hierarchically organized nanostructure.
J.-M. Huang, Z.-Q. Lin, D.-S. Chen, Org. Lett., 2012,
14, 22-25.
The combination of Re2O7 as catalyst and triphenyl
phosphite as a reductant enables the deoxygenation of unactivated aliphatic
epoxides to alkenes. The reaction proceeds stereospecifically with variously
substituted epoxides under neutral conditions and tolerates various functional
groups.
T. Nakagiri, M. Murai, K. Takai, Org. Lett.,
2015,
17, 3346-3349.
A stereoinvertive deoxygenation of trans-3-arylglycidates provides
thermodynamically less stable (Z)-cinnamate esters by using nickel
triflate and triphenylphosphine. The reaction offers broad functional group
tolerance and affords the corresponding (Z)-cinnamate esters in high
yields and with moderate to high E/Z ratios.
S. Akkarasamiyo, S. Chitsomkhuan, S. Buakaew, J. S. M. Samec, P. Chuawong, P.
Kuntiyong, Synlett, 2022,
33,
1353-1356.
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.
An easily accessible copper(I)/N-heterocyclic carbene (NHC) complex enables a
regioselective allylic reduction of allylic bromides with (TMSO)2Si(Me)H
as hydride source. The reaction provides aryl- and alkyl-substituted branched
α-olefins in good yields, which are valuable building blocks for synthesis.
T. N. T. Nguyen, N. O. Thiel, F. Pape, J. F. Teichert, Org. Lett.,
2016, 18, 2455-2458.
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.
A tetramethylthiourea-mediated stereospecific deoxygenation of respective
cis- and trans-cyanoepoxides in ethanol enables an efficient
synthesis of >99% diastereopure Z- and E-alkenyl nitriles. The
desired products are obtained in excellent yields.
Y. Zhang, S. Shi, Z. Yang, J. Org. Chem., 2024, 89,
2748-2758.
A tetramethylthiourea-mediated stereospecific deoxygenation of respective
cis- and trans-cyanoepoxides in ethanol enables an efficient
synthesis of >99% diastereopure Z- and E-alkenyl nitriles. The
desired products are obtained in excellent yields.
Y. Zhang, S. Shi, Z. Yang, J. Org. Chem., 2024, 89,
2748-2758.