151200-14-5Relevant articles and documents
Cinchona-derived prolinamide in Br?nsted acidic ionic liquids: A novel and recyclable catalytic system for asymmetric aldol reaction
Lou, Lan-Lan,Zhang, Jiong,Du, Huanling,Zhao, Bo,Li, Shanshan,Yu, Wenjun,Yu, Kai,Liu, Shuangxi
, p. 109 - 114 (2016)
Cinchonine-derived prolinamide in Br?nsted acidic ionic liquids was utilized for the first time as a novel and recyclable catalytic system for the asymmetric direct aldol reaction of acetone with aromatic aldehydes. The effects of the Br?nsted acidity and amount of ionic liquid, co-solvents, catalyst amount, and reaction temperature on the catalytic activity and enantioselectivity were studied in detail. Good to high yields and ee values were achieved for the aldol reaction of various aromatic aldehydes with neat acetone in 1-methylimidazolium tetrafluoroborate ([Hmim]+BF4-) in the presence of 10 mol% of catalyst at room temperature. [Hmim]+BF4- was also identified as a Br?nsted acid additive for the reaction and beneficial to the enhancement of catalytic performance. Moreover, the enhanced interaction between prolinamide and acidic ionic liquid facilitated the recoverability and reusability of organocatalyst. The catalyst recycling experiments indicated that there was only a slight loss in activity and enantioselectivity after four runs.
Electrophilic chemistry of thia-PAHs: Stable carbocations (NMR and DFT), S-alkylated onium salts, model electrophilic substitutions (nitration and bromination), and mutagenicity assay
Laali, Kenneth K.,Chun, Joong-Hyun,Okazaki, Takao,Kumar, Subodh,Borosky, Gabriela L.,Swartz, Carol
, p. 8383 - 8393 (2007)
(Chemical Equation Presented) First examples of stable carbocations are reported from several classes of thia-PAHs with four fused rings, namely, benzo[b]naphtho[2,1-d]thiophene (1) and its 3-methoxy derivative (2), phenanthro[4,3-b]thiophene (3) and its 7-methoxy (4), 10-methoxy (5), and 9-methoxy (6) derivatives, phenanthro[3,4-b]thiophene (7) and its 7-methoxy (8) and 9-methoxy (9) derivatives, and 3-methoxybenzo[b]naphtha[1,2-d]thiophene (11). In several cases, the resulting carbocations were also studied by GIAO-DFT. Charge delocalization modes in the resulting carbocations were probed, A series of S-alkylated onium tetrafluoroborates, namely, 1Me+, 1Et+, 2Et+, and 7Me+ (from 1, 2, and 7), 10Me+ and 10Et+ (from benzo[b]naphtha[1,2-d]thiophene 10), 12Me+ and 12Et+ (from phenanthro[3,2-b][1]benzothiophene 12), 13Me+ (from 3-methoxyphenanthro[3,2-b]benzothiophene 13), 14Me+ (from phenanthro[4,3-b][1]-benzothiophene 14), and 15Me + (from 3-methoxyphenanthro[4,3-b][1]benzothiophene 15), were synthesized. PAH-sulfonium salts 1Me+, 1Et+, 10Me +, 10Et+, 12Me+, and 14Me+ proved to be efficient akylating agents toward model nitrogen nucleophile receptors (imidazole and azaindole). Facile transalkylation to model nucleophiles (including guanine) is also supported by favorable reaction energies computed by DFT. Ring opening energies in thia-PAH-epoxides from 1, 3, and 7 and charge delocalization modes in the resulting carbocations were also evaluated. The four-ring-fused thia-PAHs 1, 2, 3, 4, 5, 7, 8, and 11 are effectively nitrated under extremely mild conditions. Nitration regioselectivity corresponds closely to protonation under stable ion conditions. Bromination of 4 and 6 is also reported. Comparative mutagenicity assays (Ames test) were performed on 1 versus 1NO2, 5 versus 5NO2, and 11 versus 11NO2. Compound 5NO2 was found to be a potent direct acting mutagen.
Experimental and theoretical studies on polar Diels-Alder reactions of 1-nitronaphathalene developed in ionic liquids
Mancini, Pedro M. E.,Rosa, Claudia D. Della,Ormachea, Carla M.,Kneeteman, Maria N.,Domingo, Luis R.
, p. 13825 - 13834 (2013)
The reactions between 1-nitronaphthalene 1 and two nucleophilic dienes, Danishefskys diene 2 and 1-trimethylsilyloxy-1,3-butadiene 3, to yield phenanthrenols 7 and 8 developed in protic and aprotic ionic liquids (ILs) with an imidazolium cation base permit to conclude that the reactions occur in better experimental conditions than in molecular solvents. The yields obtained with protic ILs are better than those observed with aprotic ILs. In this sense, the higher yields obtained with aprotic ILs, (working at 60°C, 48 h) are comparable with the lower yields observed in protic ILs (60°C, 24 h). DFT calculations for the reaction of 1-nitronaphthalene 1 with diene 3, in the absence and in the presence of tetrafluoroborate of 1-metilimidazolium [HMIM][BF4] as protic ILs, indicate that this reaction is a domino process that comprises two consecutive processes: i) a polar Diels-Alder (P-DA) reaction between 1 and 3, and ii) an elimination of nitroso acid 5 to yield dihydrophenanthrene 11. Thermodynamic calculations indicate that while the first reaction is the rate-determining step of this domino process, the nitroso acid elimination is the driving force responsible for the formation of dihydrophenanthrene 11. Implicit and explicit solvent effects indicate that while the hydrogen bond formation between HMIM and one oxygen atom of the nitro groups favour the two reactions, implicit solvent effects modelled by PCM decelerate the P-DA reaction by a large solvation of reagents. Finally, DFT analysis of reagents offers an explanation of the catalytic role of protic ILs in these P-DA reactions.
1-Methylimidazolium tetrafluoroborate [Hmim][BF4]: An efficient acidic ionic liquid catalyst for insertion of α-diazo compounds into the N-H bonds of amines
Akbari, Jafar,Ebrahimi, Ali,Heydari, Akbar
, p. 5417 - 5419 (2014)
The reusable acidic ionic liquid, 1-methylimidazolium tetrafluoroborate [Hmim][BF4], was found to be an effective catalyst for the insertion of α-diazoacetate into the N-H bonds of amines. The corresponding products were obtained in good yields and short reaction times via a simple procedure. The catalyst could be recycled and reused without any noticeable decrease in its activity.
Synthesis, characterization, and evaluation of 10-undecenoic acid-based epithio derivatives as multifunctional additives
Geethanjali, Gorla,Padmaja, Korlipara V.,Sammaiah, Arukali,Prasad, Rachapudi B. N.
, p. 11505 - 11511 (2015/02/19)
Novel epithio compounds from alkyl epoxy undecanoates (n-alkyl, C1, C4, and C6; isoalkyl, C3, C4, and C8) were synthesized using an ammonium thiocyanate in ionic liquid 1-methylimidazolium tetrafluoroborate/H2O (2:1) solvent system in 85-90% yields by gas chromatographic (GC) analysis. The synthesized products were characterized by 1H and 13C nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography, and GC mass spectral (GC-MS) analyses and evaluated for their antioxidant, extreme pressure (EP), and antiwear (AW) properties in three different base oils, namely, epoxy jatropha fatty acid n-butyl esters (EJB), di-2-ethylhexyl sebacate (DOS), and mineral oil (S-105). Among the synthesized products, n-butyl epithio undecanoate exhibited superior antioxidant property (229.2 °C) compared to butylated hydroxytoluene (BHT, 193.8 °C) in base oil DOS and comparable performance in EJB and S-105 base oils. All of the epithio derivatives exhibited significantly enhanced weld point for the base oils EJB and DOS at 2 wt % level and displayed moderate enhancement in S-105 base oil. Methyl epithio undecanoate at 0.6% concentration exhibited considerable improvement in the wear scar of DOS base oil. The synthesized epithio derivatives have potential as multifunctional additives in lubricant formulations.
