- Palladium-catalyzed nucleophilic allylic substitution of Morita–Baylis–Hillman adducts with enamines: Synthesis of 1,5-dicarbonyl compounds
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An efficient nucleophilic allylic substitution of a variety of Morita–Baylis–Hillman adducts with enamines catalyzed by Pd(OAc)2 in the presence of ZnBr2 as a promoter is described in the present study. The reaction gives SN2-type 1,5-dicarbonyl compounds that may subsequently undergo an intramolecular conjugate addition onto the enone moiety affording the corresponding 1,4-adducts. All the synthesized compounds have been isolated in moderate to good yields and fully characterized.
- Bouhalleb, Ghalia,Bouajila, Jalloul,Rezgui, Farhat
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- Direct palladium-catalyzed allylic alkylations of alcohols with enamines: Synthesis of homoallyl ketones
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An efficient, direct nucleophilic allylic substitution of α-, β- and γ-substituted alcohols with enamines, using the Pd(OAc)2/PPh3 catalyst system and ZnBr2 as a promoter in CH2Cl2 at reflux, is reported. The reaction course was dependent on the steric hindrance at the α- or γ-positions with respect to the functionalized α-carbon, selectively affording in moderate to good yields, α- or γ-homoallyl ketones, the so-called “linear” and “branched” products, respectively.
- Bouhalleb, Ghalia,Mhasni, Olfa,Poli, Giovanni,Rezgui, Farhat
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supporting information
p. 2525 - 2529
(2017/06/13)
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- Unexpected nucleophilic behaviour of free-radicals generated from α-iodoketones
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The unexpected nucleophilic reactivity of free-radicals generated from α-iodoketones is reported; two different procedures, either employing tin or the more environmentally acceptable ethylsulfone-based coupling reagent 5c have been developed.
- De Dobbeleer, Corinne,Pospiil, Jii,De Vleeschouwer, Freija,De Proft, Frank,Marko, Istvan E.
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supporting information; experimental part
p. 2142 - 2144
(2009/09/06)
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- Efficient access to functionalised medium-ring systems by radical fragmentation/radical addition to α-iodoketones
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Functionalised medium-ring systems of various sizes can be efficiently prepared by a novel approach that embodies a radical-induced fragmentation of bicyclic β-hydroxy ketones, followed by a second radical-coupling reaction. The unexpected reactivity of α
- De Dobbeleer, Corinne,Ates, Ali,Vanherk, Jean-Christophe,Markó, István E.
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p. 3889 - 3893
(2007/10/03)
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- Esters α-methyleniques par substitution d'ethers et d'acetates derives de l'α-(hydroxymethyl)acrylate d'ethyle
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α-(Methylene)alkanoic esters are prepared in high yields by substitution of α-(acetoxymethyl)acrylates using Grignard reagents in the presence of a catalytic amount of copper(I) salt.This reaction can be applied to lithium enolates of esters and ketones a
- Amri, Hassen,Rambaud, Monique,Villieras, Jean
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- Utilization of Ethyl 2-((Phenylsulfonyl)methyl)acrylate for the Synthesis of α-Methylenevalerolactones
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A two-step sequence is described for conversion of cyclic and acyclic ketone enolates into α-methylenevalerolactones.The first step involves Michael addition to ethyl α-((phenylsulfonyl)methyl)acrylate 1 with concomitant elimination of PhSO2 and formation of unsaturated keto esters 2-7.In the next sequence chemoselective ketone reduction is usually followed by spontaneous lactonization on acidification.Contrary to the five- and six-membered ring systems, the cis-fused isomer predominates in the seven- and eight-membered ring compounds 12 and 13.Spiro α-methylenevalerolactones 17a,b are as well obtainable by a short sequence of steps from 2-oxocyclohexanecarboxylate and 1.
- Ghera, Eugene,Yechezkel, Tamar,Hassner, Alfred
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p. 5977 - 5982
(2007/10/02)
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