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Synthesis of alkenes by anti-eliminations
Name Reactions
Recent Literature
Heating with NaI and DBU in dimethoxyethane effected clean
elimination of tosylates to terminal olefins. This simple one-pot procedure was
also applied to tosylates derived from an Evans Aldol Reaction.
P. Phukan, M. Bauer, M. E. Maier, Synthesis, 2003, 1324-1328.
The preparation of any length alkenyl halide from inexpensive starting
reagents is reported. Standard organic transformations were used to prepare
straight chain α-olefin halides in excellent overall yields with no
detectable olefin isomerization and full recovery of any unreacted starting
material.
T. W. Baughman, J. C. Sworen, K. B. Wagener, Tetrahedron, 2004, 60, 10943-10948.
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.
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. Concellón, H. Rodriguez-Solla, C. Simal, M. Huerta, Org. Lett.,
2005, 7, 5833-5835.
A microwave-assisted, metal-free direct decarboxylative elimination of
arylacetic acids in the presence of PIFA as oxidant readily provides alkenes in
good yields.
S.-W. Wu, J.-L. Liu, F. Liu, Org. Lett.,
2016,
18, 1-3.
The use of TMSO-/Bu4N+ as Lewis base activator
enables highly stereoselective aza-Peterson olefinations from bench-stable
α,α-bis(trimethylsilyl)toluene reagents and N-substituted imines. N-t-butanesulfinyl
imines were utilized for the synthesis of Z-stilbenes with excellent
selectivities, while N-aryl imines generated E-stilbenes under
identical reaction conditions via syn-elimination of an in situ formed
hypervalent silicate.
M. Das, D. F. O'Shea, Org. Lett., 2016, 18,
336-339.
A samarium-promoted synthesis of (E)-nitroalkenes from
1-bromo-1-nitroalkan-2-ols in high yields together with an efficient preparation of the
1-bromo-1-nitroalkan-2-ols constitutes a simple and advantageous alternative
toward nitroalkenes with total E-stereoselectivity. A mechanism is proposed to
explain the E-stereoselectivity of the β-elimination reaction.
J. M. Concellón, P. L. Bernad, H. Rodríguez-Solla, C. Concellón, J. Org. Chem., 2007,
72, 5451-5423.
A zinc carbenoid-mediated chain extension of β-dicarbonyl compounds
provides access to α,β-unsaturated-γ-keto esters and amides with complete E selectivity
via an intermediate
zinc enolate, which is treated sequentially with iodine and DBU.
M. D. Ronsheim, C. K Zercher, J. Org. Chem., 2003, 68,
4535-4538.
Triphosgene and DMAP as Mild Reagents for Chemoselective Dehydration of
Tertiary Alcohols
M. O. Ganiu, A. H. Cleveland, J. L. Paul. R. Kartika,
Org. Lett., 2019, 21, 5611-5615.
The reaction of organocerium reagents, generated in situ from aryl and
heteroaryl lithium compounds, with cycloalkanones proceeds cleanly to provide
alkoxides. Addition of MsCl or SOCl2 with DBU gave aryl-substituted
cycloalkenes in good yields. A short total synthesis of (±)-laurokamurene B is
described.
J. Tallineau, G. Bashiardes, J.-M. Coustard, F. Lecornué, Synlett, 2009,
2761-2764.