Categories: C-C Bond Formation > Oxygen-containing molecules > α,β-unsaturated compounds >
Synthesis of α,β-unsaturated compounds
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Recent Literature
A copper(I)-catalyzed carboxylation reaction of aryl- and alkenylboronic
esters under CO2 showed wide generality with higher functional group
tolerance compared to the corresponding Rh(I)-catalyzed reaction.
J. Takaya, K. Ukai, N. Iwasawa, Org. Lett.,
2008,
10, 2697-2700.
Treatment of 2,2-dimethylpropan-1,3-diol esters of aryl- and alkenylboronic
acids with a catalytic amount of [Rh(OH)(cod)]2 in the presence
of 1,3-bis(diphenylphosphino)propane and CsF in dioxane at 60°C under carbon
dioxide atmosphere gave carboxylic acids in good yields.
K. Ukai, M. Aoki, J. Takaya, N. Iwasawa, J. Am. Chem. Soc.,
2006,
128, 8706-8707.
The presence of LICl enabled an efficient process for the carboxylation of
functionalized organozinc reagents with CO2 in DMF as solvent.
K. Kobayashi, Y. Kondo, Org. Lett., 2009,
11, 2035-2037.
Formamides undergo addition reactions across alkynes and 1,3-dienes by
nickel/Lewis acid catalysis to give stereo- and regioselectively various α,β-
and β,γ-unsaturated amides. The presence of Lewis acid cocatalysts is crucial,
and formamide coordination to the Lewis acid is considered to be responsible for
the activation of their formyl C-H bonds probably through oxidative addition to
nickel(0).
Y. Nakao, H. Idei, K. S. Kanyiva, T. Hiyama, J. Am. Chem. Soc., 2009,
131, 5070-5071.
A palladium-catalyzed cross-coupling reaction between organoboronic acids and
commercially available N-methoxy-N-methylcarbamoyl chloride allows
the synthesis of Weinreb benzamides and heteroaromatic analogues, as well as α,β-unsaturated Weinreb
amides. This simple protocol is also
applicable to the use of potassium organotrifluoroborates.
R. Krishnamoorthy, S. Q. Lam, C. M. Manley, R. J. Herr, J. Org. Chem., 2010,
75, 1251-1258.
A convenient approach to selectively prepare a wide range of functionalized
propiolic acids was developed by AgI-catalyzed carboxylation of terminal alkynes
using carbon dioxide as carboxylative agent under ligand-free conditions.
X. Zhang, W.-Z. Zhang, X. Ren, L.-L. Zhang, X.-B. Lu, Org. Lett., 2011,
13, 2402-2405.
Pd(0)-catalyzed carbonylation of (Z)-2-en-4-yn carbonates in the presence
of CO and an alcohol gives vinylallenyl esters with an exclusively E-configuration
in high yields. The unreactivity of E-configured enyne carbonates may
indicate that the reaction is promoted via the cooperative coordination of
palladium with both alkynyl and carbonate moieties.
G. E. Akpınar, M. Kuş, M. Uçncu, E. Karakuş, L. Artok, Org. Lett., 2011,
13, 748-751.
