Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

A highly α-regioselective N-nucleophilic allylic substitution of cyclic MBH alcohols and acetates with imidazole or benzimidazole, in toluene at reflux with an azeotropic distillation, was successfully carried out with no catalysts or additives, affording the corresponding N-substituted imidazole derivatives in good yields. On the other hand, in refluxing toluene or methanol, the aza-Michael addition of imidazole onto acyclic MBH alcohols was performed using DABCO as an additive, leading to the corresponding 1,4-adducts in 70–84% yields

Asymmetric synthesis of 1,2- and 1,4-dihydroquinolines

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. Asymmetric synthesis of dihydroquinolines by addition of organometallic reagents (RM) on a chiral 3-quinolinyl aminal was studied. 1,2-adducts were obtained with good regio- and diastereoselectivity

Et3B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

A practical and efficient palladium-catalyzed direct allylation of β-dicarbonyl compounds with both cyclic and acyclic Morita–Baylis–Hillman (MBH) alcohols, using Et3B as a Lewis acid promoter, is described herein. A wide range of the corresponding functionalized allylated derivatives have been obtained in good yields and with high selectivity

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

International audienceAn efficient synthesis of a series of γ-ketoallylphosphonates through a direct conversion of both primary and secondary Morita–Baylis–Hillman (MBH) alcohols by trialkyl phosphites with or without DMAP, used as additive, and under solvent-free conditions, is described herein for the first time. Subsequently, a highly regioselective Luche reduction of the primary phosphonate 2a (R = H) gave the corresponding γ-hydroxyallylphosphonate 5 that further reacted with tosylamines in the presence of diiodine (15 mol %) as a catalyst, affording the corresponding S N 2-type products 6a–d in 63 to 70% isolated yields. Alternatively, the alcohol 5 produced the corresponding acetate 7 which, mediated by Ce(III), was successfully converted into the corresponding γ-aminoallylphosphonates 8a–d. 290

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

<p>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.</p