L‐Proline‐Catalyzed Activation of Methyl Ketones or Active Methylene Compounds and DMF‐DMA for Syntheses of (2E)‐3‐Dimethylamino‐2‐ propen‐1‐ones

Abstract

A cascade organocatalysis is reported for the nucleophilic and electrophilic dual activation taking place in the reaction of methyl ketones or active methylene compounds with DMF‐DMA (N,N‐dimethylformamide dimethyl acetal). L‐Proline serves as an efficient organocatalyst in the covalent and noncovalent synchronous mode for the ambiphilic activation of various aryl, heteroaryl, and styryl methyl ketones, cyclic ketones, and 1,3‐diketones with DMF‐DMA to achieve the convenient syntheses of the versatile synthons (2E)‐1‐aryl/heteroaryl/styryl‐3‐(dimethylamino)‐2‐propen‐1‐ones, (E)‐α‐[(dimethylamino)formylidene]cycloalkanones, and (E)‐2‐(dimethylamino)formylidene‐1,3‐diketones in high yields under solvent‐free conditions.

Synthesis, C–H bond functionalisation and cycloadditions of 6-styryl-1,2-oxathiine 2,2-dioxides

“…The following styrylketones and enaminoketones were obtained by standard procedures and possessed spectroscopic and physical data in agreement with literature data: (E)-4-(4methoxyphenyl)but-3-en-2-one, 37 (E)-4-(4-nitrophenyl)but-3-en-2-one, 38 (E)-4-(4-(4-trifluoromethyl)phenyl)but-3-en-2-one, 39 (E)-4-(2-bromophenyl)but-3-en-2-one 40 and (1E,4E)-1-(dimethylamino)-5-phenylpenta-1,4-dien-3-one. 41 Preparation of enaminoketones (1E,4E)-1-(Dimethylamino)-5-phenylpenta-1,4-dien-3-one 2a. 4-Phenyl-3-buten-2-one (5.00 g, 34.2 mmol) was dissolved in DMFDMA (11.4 mL, 85.5 mmol, 2.5 eq.)…”

Expedient synthesis of highly substituted 3,4-dihydro-1,2-oxathiine 2,2-dioxides and 1,2-oxathiine 2,2-dioxides: revisiting sulfene additions to enaminoketones

“…3-(Dimethylamino)-1-(4pyridyl)-2-propen-1-one (9j) was obtained by heating 4-acetylpyridine in DMFDMA containing 10 mol % L-proline. 44…”

New enaminone sesquiterpenic: TiCl4-catalyzed synthesis, spectral characterization, crystal structure, Hirshfeld surface analysis, DFT studies and cytotoxic activity

“…Due to their rich applications, many synthesis approaches to these compounds have been developed.The most popular route for the synthesis of β-enaminones is the condensation of βdicarbonyl compounds with amines, or activation of methylene ketones by dialkylamino dimethyl acetals [15]. Various modified synthetic pathways have been reported in literature for the synthesis of β-enaminones using Lewis acids, inorganic acids, ionic liquids, and transition metal catalysts [16].…”