Farhat Rezgui

DMAP-catalyzed hydroxymethylation of 2-cyclohexenones in aqueous medium through Baylis-Hillman reaction

Abstract Reaction of 2-cyclohexenones 1a-d with aqueous formaldehyde, catalyzed by DMAP in THF, affords the corresponding 2-(hydroxymethyl)-2-cyclohexenones 2a-d in good yields.

ASYMMETRIC SYNTHESIS OF 1,2- AND 1,4-DIHYDROQUINOLINES

Abstract Asymmetric synthesis of dihydroquinolines by addition of organometallic reagents on a chiral 3-quinolinyl aminal was studied. 1,2-Adducts were obtained with good regio- and diastereoselectivity. The absolute configuration for 1,2-adducts was determined by X-ray analysis and for 1,4-adducts by chemical correlation.

Réaction régiospécifique des carbanions stabilisés avec la 2-(acétoxyméthyl)cyclohex-2-én-1-one: Synthèse de diénones bicycliques

Abstract Regiospecific replacement of acetoxy group in 2-(acetoxymethyl)-2-cyclohexenone 1 by stabilized carbanions, leads to S N 2 type products 2a-g , 5 and 6 . Bicyclic dienones 4 are prepared in “ one pot ” from the reaction of 2 with K 2 CO 3 in refluxing absolute ethanol.

Regioselective S-allylation of thiols with cyclic Baylis–Hillman acetates

An efficient and mild S-allylation of thiols with cyclic Baylis–Hillman acetates with no need of a transition-metal-catalyst or an expensive additive is described. Allyl sulfides are prepared in good to excellent yields (60–97%) and a single regioisomer was observed in all cases.\absfigure{gsrp809453ab01} GRAPHICAL ABSTRACT

Regioselective reaction of a cyclic Baylis-Hillman adduct with alcohols and thiols

Cyclic Baylis-Hillman adduct 1 reacts with alcohols and thiols in the presence of p-TsOH to give regioselectively the corresponding allylic ethers 4 and thioethers 6 in satisfactory to good yields.

Transition-metal-free nucleophilic allylic substitutions of Morita–Baylis–Hillman bromides with aliphatic and aromatic amines

ABSTRACT A simple protocol for the preparation of functionalized allylic amines under mild, transition-metal-free conditions from the reaction of Morita–Baylis–Hillman (MBH) bromides with amines is described herein. The treatment of the MBH bromides with various amines in the presence of NaI and Et3N in aqueous acetone solution and at room temperature affords the corresponding functionalized allyl amines in moderate to good yields (45–87%). The reaction is rapid and carried out at room temperature. GRAPHICAL ABSTRACT

“On water” reaction of deactivated anilines with 4-methoxy-3-buten-2-one, an effective butynone surrogate

Poorly nucleophilic aromatic amines (nitroanilines, chloroanilines, etc.) react readily and selectively with trans-4-methoxy-3-buten-2-one, a convenient, effective and inexpensive surrogate for 3-butyn-2-one, to afford (Z)-enaminones. The efficiency of the reaction mostly lies in the use of water as a solvent, which enhances the reaction rate by a 45 to 200-fold factor with regard to other media.

General and Efficient Transesterification of β-Keto Esters with Various Alcohols Using Et3N as a Brønsted Base Additive

Abstract Transesterification of β-keto esters with a wide variety of allyl, benzyl, propargyl, and alkyl alcohols using, for the first time, commercially available and inexpensive Et3N as a Brønsted base additive, is efficiently performed in toluene at reflux. The corresponding esters are exclusively obtained in 57–98% yields with no trace amounts of γ,δ-ketones, usually expected from the decarboxylative Carroll rearrangement. GRAPHICAL ABSTRACT

Potential antioxidant activity of Morita-Baylis-Hillman adducts

The wide variety of potent biological activities of Morita-Baylis-Hillman adducts (MBH) encouraged us to synthesize new series of products belonging to this class of compounds, possessing different functionalities and exhibiting potential antioxidant activity. As part of our on-going program on targeting molecules with antioxidant activity, we describe herein different DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activities of MBH alcohols and their derivatives including acetates, phosphonates and hydrazonophosphonates. The obtained results showed that the strongest DPPH radical scavenging activity was observed in the case of hydrazonophosphonates in comparison to the other MBH derivatives.

A direct synthetic route to allyl sulfides from cyclic Morita–Baylis–Hillman alcohols

ABSTRACT p-TsOH-mediated the direct α-substitution of cyclic Morita–Baylis–Hillman alcohols with aliphatic and aromatic thiols in refluxing THF. The reaction proceeded with complete α-regioselectivity and provided the corresponding allyl sulfides in moderate to good yields. GRAPHICAL ABSTRACT