Mechanistic Investigation of DBU-Based Ionic Liquids for Aza-Michael Reaction: Mass Spectrometry and DFT Studies of Catalyst Role

Cândido, Augusto A.; Rozada, Thiago C.; Rozada, Andrew M.F.; Souza, João Raul B. de; Pilau, Eduardo Jorge; Rosa, Fernanda A.; Basso, Ernani A.; Gauze, Gisele F.

doi:10.21577/0103-5053.20200066

Cited by 3 publications

(2 citation statements)

References 26 publications

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“…In order to check the chemical structures and purities, all compounds were characterized by 1 H and 13 C NMR, FTIR and elemental analysis (see Figure S5 in Supporting Information ). The syntheses of [MIMH][MeSO 3 ], [TMGH][MeSO 3 ] and [DBUH][HSO 4 ] were described in previous works [ 14 , 35 ].…”

Section: Methodsmentioning

confidence: 99%

New Protic Ionic Liquids as Potential Additives to Lubricate Si-Based MEMS/NEMS

et al. 2023

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The motivation for this work was to develop new protic ionic liquids (PILs) as additives for the lubrication of micro and nanoelectromechanical systems (MEMS and NEMS). Ten PILs based on the combination of methylimidazolium ([MIMH]), 4-picolinium ([4-picH]), pyridinium ([PyrH]), 1,8-diazabicyclo[5.4.0]-undec-7-ene-8-ium ([DBUH]) and tetramethylguanidinium ([TMGH]) cations with hydrogen sulfate([HSO4]) and mesylate ([MeSO3]) anions were tested as additives in polyethylene glycol (PEG200) to lubricate steel/silicon and silicon/silicon contacts. The best additive was [4-picH][HSO4], which adsorbed strongly on the Si surface, leading to a protective film that reduced wear by up to 15 times compared to PEG200.

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Section: Methodsmentioning

confidence: 99%

New Protic Ionic Liquids as Potential Additives to Lubricate Si-Based MEMS/NEMS

et al. 2023

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“…It can be assumed that similarly to the proposed mechanism in the aza-Michael addition of simple substrates [43] , the acidic hydrogen of protonated DBU may form a hydrogen bond with the carbonyl oxygen of the steroidal substrate, while the anion may increase the electron density on the sulfur atom of the thiol reaction partner either via deprotonation or H-bond formation.…”

Section: Thiol-michael Addition Reactionsmentioning

confidence: 99%

Synthesis of Steroidal Thioethers via [HDBU][OAc]‐Mediated Michael Addition of Thiols to 16‐Dehydropregnenolone

et al. 2022

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In the catalytic addition of thiols to 16‐dehydropregnenolone fourteen thioethers were prepared via thiol‐Michael addition reaction in the presence of different aliphatic and aromatic thiols as reagents. [HDBU][OAc] was proved to be an efficient catalyst and solvent providing thioether derivatives in good to excellent yields. The ionic liquid could be reused for five times without noticeable loss of activity. The structures of compounds were confirmed by 1H‐, 13C NMR and IR spectroscopy and mass spectral analysis. A series of these pregnenolone derivatives were evaluated for their cytotoxic activity on breast cancer (MDA‐MB‐231, MCF7) cell lines.

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Super Base Derived Ionic Liquids: A Useful Tool in Organic Synthesis

Chatterjee

Bhukta

Dandela

2022

COC

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Over the last few decades, ionic liquids have been raised as a great appliance to pursue many organic transformations. In the present research, the synthetic application of ILs has emerged largely as solvents, additives, or catalysts. With the developing commercial methods, task-specific ionic liquids have been constructed by appointing guanidine, amidine and other superbasic cations. By the nature of the cation or the anion, the properties of the ionic liquids can be adjusted. In this regard, superbasic ionic liquids have been derived from both acyclic and cyclic guanidine or amidine derivatives. In particular, some common super bases such as 1,1,3,3-tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), are used to design these special type of ionic liquids. These superbasic ionic liquids have shown a potential activity to accelerate many organic transformations including alcoholysis, esterification, multi-component reaction, Knoevenagel reaction, Michael addition, cyclization, etc. Additionally, because of their novel properties including high liquid range, nonvolatility, high thermal and chemical stability, these classic ionic liquids have a potential environmental impact and they are often found to play a promising role in the field of catalysis, electrochemistry, spectroscopy, and materials science. Not only that, the application of superionic liquids has been widely spread in the industrial and research area, especially, for the chemical transformation of CO2. This review aims to portray an outlook on the organic syntheses that have been promoted by superionic liquids in the last five years.

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Mechanistic Investigation of DBU-Based Ionic Liquids for Aza-Michael Reaction: Mass Spectrometry and DFT Studies of Catalyst Role

Cited by 3 publications

References 26 publications

New Protic Ionic Liquids as Potential Additives to Lubricate Si-Based MEMS/NEMS

New Protic Ionic Liquids as Potential Additives to Lubricate Si-Based MEMS/NEMS

Synthesis of Steroidal Thioethers via [HDBU][OAc]‐Mediated Michael Addition of Thiols to 16‐Dehydropregnenolone

Super Base Derived Ionic Liquids: A Useful Tool in Organic Synthesis

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