Microwave irradiation or low temperature improved synthesis of antiparasitic Morita-Baylis-Hillman adducts

Abstract

Relatamos a síntese de 24 adutos de Morita-Baylis-Hillman (3a-3l/6a-6l) usando irradiação de microondas a 80 o C ou protocolo convencional a 0 o C para promover reações entre aldeídos aromáticos e acrilato de metila ou acrilonitrila (81-99%). Provamos que a reação de formação do acrilato de 2-hidroxi(4-bromofenil)metila é reversível a 120 o C.It is reported the synthesis of 24 Morita-Baylis-Hillman adducts (3a-3l/6a-6l) using microwave irradiation at 80 o C or conventional protocol at 0 o C to promote the reactions between aromatic aldehydes and methyl acrylate or acrylonitrile (81-99%). It is shown that the reaction of 2-hydroxy(4-bromophenyl)methyl acrylate formation is reversible at 120 o C.

Morita‐Baylis‐Hillman Reaction Accessing GABA Intermediates: Synthesis of New Lipophilic Hydroxylated γ‐Nitroesters

“…To optimize the experimental conditions the MBH reaction was performed using fatty aldehyde 7 g as template. The experiments were carried out in agreement to literature using alkyl aldehydes as starting materials to MBH adduct synthesis . The reaction progress was monitored by Thin Layer Chromatography (TLC) and by Gas Chromatography coupled to Flame Ionization Detector (GC‐FID).…”

Pentapeptide Nanoreactor as a Platform for Halogenations, Diels–Alder Reaction, and Morita–Baylis–Hillman Reaction

“…Finally, we have used the peptide 1 reactor for the Morita–Baylis–Hillman (MBH) reaction between benzaldehyde and ethyl acrylate in methanol in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO). 30 The MBH reaction of benzaldehyde and ethyl acrylate in methanol increases 1.5-fold in the presence of the supramolecular nanoreactor 1 (Figure 5c) in 96 h. The experimental details are given in the Supporting Information.…”

Synthesis of 16 New Hybrids from Tetrahydropyrans Derivatives and Morita˗Baylis˗Hillman Adducts: In Vitro Screening against Leishmania donovani

“…[ 7 ], MBHR is an exquisite reaction and each reaction must have its experimental parameters carefully optimized as an individual problem. However, some facts are incontestable: the MBHR between methyl acrylate reacting with p -bromobenzaldehyde is reversible at elevated temperatures [ 21 ]; several MBHR are faster at 0 °C than at room temperature [ 23 , 24 ]; and the type of solvent (aprotic or protic) [ 25 , 26 ] and the phenol or naphthol additives modifies the reactions rate. We can see in Table 1 (Entries 1, 2, 4–8, 10 ) and Table 2 (Entries 1–6, 8 and 10) that it used t-buOH/H 2 O at 80 °C under microwave irradiation as the first experimental attempt [ 21 ].…”

“…However, some facts are incontestable: the MBHR between methyl acrylate reacting with p -bromobenzaldehyde is reversible at elevated temperatures [ 21 ]; several MBHR are faster at 0 °C than at room temperature [ 23 , 24 ]; and the type of solvent (aprotic or protic) [ 25 , 26 ] and the phenol or naphthol additives modifies the reactions rate. We can see in Table 1 (Entries 1, 2, 4–8, 10 ) and Table 2 (Entries 1–6, 8 and 10) that it used t-buOH/H 2 O at 80 °C under microwave irradiation as the first experimental attempt [ 21 ]. When this condition was not efficient, low temperatures were used (0 °C) in DMF/water as the solvent mixture and used phenol as the additive, increasing yields (Entries 7, 9 and 11, Table 2 ).…”

“…In connection with our interest in the discovery of new Morita-Baylis-Hillman adducts with promising leishmanicidal and other bioactivities [ 5 , 18 , 19 , 20 , 21 ], we present here the design, synthesis, and in vitro screening against Leishmania donovani of sixteen new molecular hybrids ( 8a – h and 9a – h , Figure 2 ). It is important to note here that our design is based on the fact that inhibitors of opioid receptors participate in the mechanism of action against leishmaniasis interfering with the immune system, not only participating in the function of the immune cells, but also modulating innate and acquired immune responses [ 22 ].…”