4565-20-2Relevant academic research and scientific papers
New uncharged 2-thienostilbene oximes as reactivators of organophosphate-inhibited cholinesterases
?ade?, Tena,?kori?, Irena,Bari?, Danijela,Kovarik, Zrinka,Lasi?, Kornelija,Marini?, ?eljko,Mlaki?, Milena,Pu?ek, Ivana,Ratkovi?, Ana
, (2021/11/27)
The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) by organophosphates (OPs) as nerve agents and pesticides compromises normal cholinergic nerve signal transduction in the peripheral and central nervous systems (CNS) leading to cholinergic crisis. The treatment comprises an antimuscarinic drug and an oxime reactivator of the inhibited enzyme. Oximes in use have quaternary nitrogens, and therefore poorly cross the brain–blood barrier. In this work, we synthesized novel uncharged thienostilbene oximes by the Wittig reaction, converted to aldehydes by Vilsmeier formylation, and transformed to the corresponding uncharged oximes in very high yields. Eight trans,anti-and trans,syn-isomers of oximes were tested as reactivators of nerve-agent-inhibited AChE and BChE. Four derivatives reactivated cyclosarin-inhibited BChE up to 70% in two hours of reactivation, and docking studies confirmed their productive interactions with the active site of cyclosarin-inhibited BChE. Based on the moderate binding affinity of both AChE and BChE for all selected oximes, and in silico evaluated ADME properties regarding lipophilicity and CNS activity, these compounds present a new class of oximes with the potential for further development of CNS-active therapeutics in OP poisoning.
Lipids as versatile solvents for chemical synthesis
Bayer, Annette,Gevorgyan, Ashot,Hopmann, Kathrin H.
supporting information, p. 7219 - 7227 (2021/09/28)
Development of safe, renewable, cheap and versatile solvents is a longstanding challenge in chemistry. We show here that vegetable oils and related systems can become prominent solvents for organic synthesis. Suzuki-Miyaura, Hiyama, Stille, Sonogashira and Heck cross-couplings proceed with quantitative yields in a range of vegetable oils, fish oil, butter and waxes used as solvents. Appropriate methodologies for high-throughput screening and sustainable isolation techniques applicable for vegetable oils and related lipids are presented.
Palladium(ii) ligated with a selenated (Se, CNHC, N-)-type pincer ligand: An efficient catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling in water
Sharma, Kamal Nayan,Satrawala, Naveen,Srivastava, Avinash Kumar,Ali, Munsaf,Joshi, Raj Kumar
, p. 8969 - 8976 (2019/10/28)
A new 1-[N-benzylacetamido]-3-[1-(2-phenylselenylethyl)]benzimidazolium chloride (L), the precursor of a novel (Se, CNHC, N-)-type pincer ligand (L) was synthesised in high yield through a sequence of consecutive reactions of 1H-benzimidazole with ethylene dichloride, sodium selenophenolate, and N-benzyl-2-chloroacetamide. The palladium-promoted reaction of L with PdCl2 resulted in a moisture- and air-insensitive complex [Pd(L-H2Cl)Cl] (1), which demonstrated outstanding catalytic potential for Mizoroki-Heck coupling of aromatic bromides and chlorides (with yields up to 94% and 70%, respectively) at very low catalyst loading (0.2 mol%) and under mild reaction conditions in water. The complex (1) was also investigated for Suzuki-Miyaura coupling and found to be selectively efficient (yields up to 94%) for Suzuki-Miyaura coupling of aromatic bromides at 0.01 mol% of 1 in water. All coupling reactions were carried out in the green and economical solvent, water, which is highly desirable for bulk synthesis of complex molecules in industry. During the catalytic process, complex 1 converted into PdSe nanoparticles (NPs, size range 5-6 nm) in situ. The morphology and composition of these NPs were analysed through high-resolution transmission electron microscopy and transmission electron microscopy-energy dispersive X-ray spectroscopy, respectively. The core-level, X-ray photoelectron spectroscopy analysis confirmed the presence of stable Pd0 and Pd2+ oxidation states in these PdSe NPs. Based on further experimental investigations, these nanoparticles were found to work as a stock of true catalytic species. The hot filtration test, as well as the two-phase test, confirmed the largely homogeneous nature of the catalytic process, which probably proceeds by leaching of solution-phase Pd species from these NPs.
Decarboxylative Arylation of α,β-Unsaturated Carboxylic Acids Using Aryl Triazenes by Copper/Ionic Liquid Combination in PEG-400
Kumar, Saurabh,Kumar Pandey, Anand,Singh, Rahul,Nand Singh, Krishna
supporting information, p. 5942 - 5946 (2018/11/10)
A practical method for the construction of stilbene derivatives has been developed via catalytic cross-coupling of cinnamic acids with aryl triazenes. The methodology offers high stereoselectivity and is endowed with broad substrate scope, high yield, and significant functional group tolerance.
The cross-coupling reaction of vinylindiums generated via hydroindation of terminal alkynes with diaryliodoniums salts
Xue, Zhao,Yang, Deyu,Wang, Chunyan
, p. 247 - 250 (2007/10/03)
In InCl3-NaBH4-MeCN system, vinylindiums generated by hydroindation of aryl terminal alkynes can undergo cross-coupling reaction with diaryliodonium salts high regio- and stereoselectively. But under the same conditions, the aliphatic terminal alkynes do not react very well.
Diversity-oriented synthesis of multisubstituted olefins through the sequential integration of palladium-catalyzed cross-coupling reactions. 2-Pyridyldimethyl(vinyl)silane as a versatile platform for olefin synthesis
Itami,Nokami,Ishimura,Mitsudo,Kamei,Yoshida
, p. 11577 - 11585 (2007/10/03)
A novel strategy for the diversity-oriented synthesis of multisubstituted olefins, where 2-pyridyldimethyl (vinyl)silane functions as a versatile platform for olefin synthesis, is described. The palladium-catalyzed Heck-type coupling of 2-pyridyldimethyl(vinyl)silanes with organic iodides took place in the presence of Pd2-(dba) 3/tri-2-furylphosphine catalyst to give β-substituted vinylsilanes in excellent yields. The Heck-type coupling occurred even with α- and β-substituted 2-pyridyldimethyl(vinyl)silanes. The one-pot double Heck coupling of 2-pyridyldimethyl(vinyl)silane took place with two different aryl iodides to afford β,β-diarylated vinylsilanes in good yields. The palladium-catalyzed Hiyama-type coupling of 2-pyridyldimethyl(vinyl)silane with organic halides took place in the presence of tetrabutylammonium fluoride to give di- and trisubstituted olefins in high yields. The sequential integration of Heck-type (or double Heck) coupling and Hiyama-type coupling produced the multisubstituted olefins in regioselective, stereoselective, and diversity-oriented fashions. Especially, the one-pot sequential Heck/Hiyama coupling reaction provides an extremely facile entry into a diverse range of stereodefined multisubstituted olefins. Mechanistic considerations of both Heck-type and Hiyama-type coupling reactions are also described.
Benzotriazole-Mediated Stereoselective Olefination of Carboxylic Esters: Transformation of α-Amino Acid Esters into Chiral Allylamines
Katritzky, Alan R.,Cheng, Dai,Li, Jianqing
, p. 3438 - 3444 (2007/10/03)
Diastereoselective trans-olefinations of carboxylic esters 3a-h have been accomplished using benzylic or allylic benzotriazole derivatives 1a-e to prepare α-(benzotriazol-1-yl) ketones 4a-i, for the subsequent reduction of 4a-i, and finally for low-valent titanium-effected dehydroxybenzotriazolylation.1 N-Protected α-amino acid esters 9a-c and 15 thus give allylamines 13a-e and 19 with virtually full retention of chirality. Mechanistic aspects of the dehydroxybenzotriazolylation are discussed.
A Novel and Efficient Route to (E)-Alk-1-enyl Boronic Acid Derivatives from (E)-1-(Trimethylsilyl)alk-1-enes and a Formal Suzuki-Miyaura Cross-coupling Reaction starting with Vinylsilanes
Farinola, Gianluca M.,Fiandanese, Vito,Mazzone, Luigia,Naso, Francesco
, p. 2523 - 2524 (2007/10/03)
A novel and highly efficient conversion of vinylsilanes into vinyl boronates is described together with their Suzuki-Miyaura cross-coupling reaction, performed without isolating the intermediate resulting from borodesilylation.
