Caroline da Ros Montes D'Oca

Síntese de novas amidas graxas a partir da aminólise de ésteres metílicos

Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce citotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs).

Synthesis of β-ketoesters from renewable resources and Meldrum's acid

β-Ketoesters are valuable building blocks for the synthesis of compounds with different biological activities. In this study, a series of fatty β-ketoesters were obtained from fatty acids and Meldrums acid using N,N-dicyclohexylcarbodiimide and dimethylaminopyridine. In addition, we demonstrate for the first time the synthesis of new fatty β-ketoesters from oleic (cis-C18:1), elaidic (trans-C18:1), ricinoleic (cis-C18:1, 12-OH), linoleic (cis,cis-C18:2), and linolenic (cis,cis,cis-C18:3) acids in good yields.

Synthesis and antiproliferative activity of novel hybrid 3-substituted polyhydroquinoline-fatty acids

This work describes the synthesis of new long-chain fatty acid polyhydroquinoline derivatives (hybrid PHQ-fatty acids) using a Hantzsch four-component reaction without the use of metals and catalyzed by non-toxic acids. The PHQ-fatty acids were synthesized from fatty β-ketoesters in the presence of sulfamic acid (H2NSO3H) in good yields (70–81%). Following the synthesis, for the first time, the in vitro antiproliferative activity of a series of long-chain PHQ-fatty acids was investigated in a glioma cell line (C6 rat malignant GBM cell line). Notably, all of the tested compounds were active against this cell line. Superior activity was observed for PHQ with a hydroxyl group on the aromatic ring and a stearic fatty acid chain, reducing the cell viability by ca. 40% at 5 μM.

One pot domino reaction accessing γ-nitroesters: synthesis of GABA derivatives

Michael addition of 1,3-dicarbonyl compounds to nitrostyrenes is efficiently promoted by hydrotalcite [Mg–Al] to afford the respective γ-nitrodicarbonyl adducts. Differently, the addition of Meldrums acid leads to a direct access of γ-nitroesters through a one pot domino process. GABA derivatives (+/−)-phenibut and (+/−)-baclofen were readily synthesized from the respective nitro adducts.

New Multicomponent Reaction for the Direct Synthesis of β-Aryl-γ-nitroesters Promoted by Hydrotalcite-Derived Mixed Oxides as Heterogeneous Catalyst

A new approach based on multicomponent/domino combined reactions for the synthesis of γ-nitroesters promoted by a mixed aluminium-magnesium oxides derived from hydrotalcite-like material was developed. Different γ-nitroesters were synthesized in 15-95% yield using Meldrum’s acid, aromatic aldehydes, nitromethane and different alcohols as reagents and solvents. The γ-aminobutyric acid derivatives, Phenibut and Baclofen, were prepared in 63 and 61% overall yield, respectively, through a two steps synthetic strategy. A mechanistic pathway was proposed based on the gas chromatography mass spectrometry (GC-MS) and electrospray ionization mass spectrometry (ESI-MS) experiments.

A new multicomponent reaction for direct synthesis of primary γ-nitroamides

A new multicomponent reaction for direct synthesis of γ-nitroamides promoted by ammonium carbonate was developed. A series of γ-nitroamides were synthesized in 35–93% yield from Meldrums acid, aromatic or aliphatic aldehydes, nitromethane and ammonium carbonate. A mechanistic pathway was proposed based on electrospray ionization mass spectrometry (ESI/MS) experiments.