Synthesis of enones

Related: α,β-unsaturated compounds
(C-C Coupling)

Name Reactions

Recent Literature

Two optimal catalytic systems for the convenient and fast α-methylenation of aldehydes with aqueous formaldehyde are described that allow short reaction times and afford the methylenated products in good to excellent yields and chemoselectivity.
A. Erkkilä, P. M. Pihko, J. Org. Chem., 2006, 71, 2538-2541.

A domino oxidation of primary alcohols gives α,β-unsaturated compounds using the combination of PCC-NaOAc and stabilized Wittig reagents.
J. Shet, V. Desai, S. Tilve, Synthesis, 2004, 1859-1863.

Water is an effective medium for the Wittig reaction over a wide range of stabilized ylides and aldehydes including especially substrates with large hydrophobic entities. Despite sometimes poor solubility of the reactants, good yields and high E-selectivities are achieved, and the rate of the reactions in water is unexpectedly accelerated.
A. El-Batta, C. Jiang, W. Zhao, R. Anness, A. L. Cooksy, M. Bergdahl, J. Org. Chem., 2007, 72, 5244-5259.

A highly efficient α alkylation of ketones with primary alcohols by the use of a recyclable palladium catalyst has been demonstrated.
M. S. Kwon, N. Kim, S. H. Seo, I. S. Park, R. K. Cheedrala, J. Park, Angew. Chem. Int. Ed., 2005, 42, 6913-6915.

o-Iodoxybenzoic acid (IBX) was found to be highly effective in oxidations adjacent to carbonyl and benzylic functionalities to form either α,β-unsaturated carbonyl compounds or conjugated aromatic carbonyl systems. Fine-tuning of the reaction conditions allowed remarkably selective transformations within multifunctional substrates.
K. C. Nicolaou, T. Montagnon, P. S. Baran, Y.-L. Zhong, J. Am. Chem. Soc., 2002, 124, 2245-2258.

(PCy₃)₂Cl₂Ru=CHPh-catalyzed Kharasch additions of trihaloalkanes across olefins provide polyhalogenated adducts, which upon hydrolysis furnish α,β-unsaturated ketones, aldehydes, or γ-hydroxybutenolides. This two-step process represents an overall acylation or carbonylation of an olefin.
B. T. Lee, T. O. Schrader, B. Martin-Matute, C. R. Kauffman, P. Zhang, M. L. Snapper, Tetrahedron, 2004, 60, 7391-7396.

The combination of Mo and cationic Au catalysts dramatically accelerated the rearrangement of diverse propargyl alcohols to yield α,β-unsaturated compounds under mild conditions, and high product yields. A practical application to the highly challenging primary propargyl alcohols and the N-alkynyl amides is achieved.
M. Egi, Y. Yamaguchi, N. Fujiwara, S. Akai, Org. Lett., 2008, 10, 1867-1870.

The use of cationic silver (AgSbF₄) as a catalyst for intra- and intermolecular alkyne-carbonyl coupling is described. Intermolecular coupling proceeds stereoselectively to afford trisubstituted enones.
J. U. Rhee, M. J. Krische, Org. Lett., 2005, 7, 2493-2495.

A novel, convenient and stereoselective synthesis of trisubstituted E-alkenones has been achieved by InCl₃-mediated chemoselective reduction of Baylis-Hillman adducts with NaBH₄ as reductant.
B. Das, J. Banerjee, N. Chowdhury, A. Majhi, H. Holla, Synlett, 2006, 1879-1882.

Various α,β-unsaturated ketones were stereoselectively synthesized in high yields by a condensation of alkenyl trichloroacetates with aldehydes using the mild base dibutyltin dimethoxide as a catalyst in the presence of methanol.
A. Yanagisawa, R. Goudu, T. Arai, Org. Lett., 2004, 6, 4281-4283.

A practical and environmentally friendly method for the oxidative rearrangement of five- and six-membered cyclic tertiary allylic alcohols to α,β-unsaturated β-disubstituted ketones by IBX in DMSO is described. Several conventional protecting groups (e.g., Ac, MOM, and TBDPS) are tolerated.
M. Shibuya, S. Ito, M. Takahashi, Y. Iwabuchi, Org. Lett., 2004, 6, 4303-4306.