52693-87-5Relevant academic research and scientific papers
Ruthenium catalyzed β-selective alkylation of vinylpyridines with aldehydes/ketonesviaN2H4mediated deoxygenative couplings
Lv, Leiyang,Li, Chao-Jun
, p. 2870 - 2875 (2021/03/14)
Umpolung (polarity reversal) tactics of aldehydes/ketones have greatly broadened carbonyl chemistry by enabling transformations with electrophilic reagents and deoxygenative functionalizations. Herein, we report the first ruthenium-catalyzed β-selective alkylation of vinylpyridines with both naturally abundant aromatic and aliphatic aldehyde/ketonesviaN2H4mediated deoxygenative couplings. Compared with one-electron umpolung of carbonyls to alcohols, this two-electron umpolung strategy realized reductive deoxygenation targets, which were not only applicable to the regioselective alkylation of a broad range of 2/4-alkene substituted pyridines, but also amenable to challenging 3-vinyl and steric-embedded internal pyridines as well as their analogous heterocyclic structures.
Addition reactions of organic carbanion equivalents via hydrazones in water
Wang, Yi-Zhan,Liu, Qi,Cheng, Liang,Yu, Song-Chen,Liu, Li,Li, Chao-Jun
supporting information, (2021/01/11)
The addition of organometallic reagents to unsaturated bonds is one of the most powerful tools for carbon–carbon bond formations. Alkylation through organometallic reagents requires stoichiometric quantity of metal and tedious anhydrous operation in most cases. Here, we report “umpolung” nucleophilic additions of hydrazones to Michael acceptors, carbonyls and imines in water. Under the catalysis of ruthenium(II), the addition reactions could be carried out in pure water to provide various alkylation products in moderate to good yields.
DNA interaction, anticancer, antibacterial, ROS and lipid peroxidation studies of quinoxaline based organometallic Re(I) carbonyls
Varma, Reena R.,Pandya, Juhee G.,Vaidya, Foram U.,Pathak, Chandramani,Dabhi, Ravi A.,Dhaduk, Milan P.,Bhatt, Bhupesh S.,Patel, Mohan N.
, (2021/05/19)
Hetero mononuclear rhenium(I) complexes (I-V) using ligands (L1-L5) [L1-L5 = 11-((2-chlorobenzylidene)hydrazono)-11H-indeno[1,2-b]quinoxaline (L1), 8-methyl-11-((4-methyl-benzylidene)hydrazono)-11H-indeno[1,2-b]quinoxaline (L2), 11-((4-bromobenzylidene) hydrazono)-8-nitro-11H-indeno[1,2-b]quinoxaline (L3), 11-((4-bromobenzylidene) hydrazono)-8-chloro-11H-indeno[1,2-b]quinoxaline (L4), 8-bromo-11-((4-fluorobenzylidene) hydrazono)-11H-indeno[1,2-b]quinoxaline (L5)] were synthesized and characterized by spectroscopic method. All the synthesized compounds have biological importance. DNA interaction studies gave information about the modes of binding and the nucleolytic efficiency of compounds. The binding of the rhenium complexes to Herring sperm DNA (HS DNA) was monitored by UV–visible spectroscopy, viscosity measurements, and molecular docking studies; groove binding was suggested as the most possible mode. The DNA-complexes binding strength was measured in terms of intrinsic binding constants. In vivo and In vitro cytotoxicity against the eukaryotic and prokaryotic cells gave the toxic nature of the synthesized compounds. An antimicrobial study was carried out by estimating MIC (Minimum Inhibitory Concentration) against two Gram-positive (S. aureus, B. subtilis) and three Gram-negative (S. marcescens, P. aeruginosa, E. coli) bacteria. All synthesized complexes are biologically more active than the corresponding ligands. Complexes were having higher MDA and H2O2 production than ligands.
Palladium-Catalyzed Defluorinative Alkylation of gem-Difluorocyclopropanes: Switching Regioselectivity via Simple Hydrazones
Lv, Leiyang,Li, Chao-Jun
supporting information, p. 13098 - 13104 (2021/05/03)
Conventional approaches for Pd-catalyzed ring-opening cross-couplings of gem-difluorocyclopropanes with nucleophiles predominantly deliver the β-fluoroalkene scaffolds (linear selectivity). Herein, we report a cooperative strategy that can completely switch the reaction selectivity to give the alkylated α-fluoroalkene skeletons (branched selectivity). The unique reactivity of hydrazones that enables analogous inner-sphere 3,3′-reductive elimination driven by denitrogenation, as well as the assistance of steric-embedded N-heterocyclic carbene ligand, are the key to switch the regioselectivity. A wide range of hydrazones derived from naturally abundant aryl and alkyl aldehydes are well applicable, and various gem-difluorocyclopropanes, including modified pharmaceutical and biological molecules, can be efficiently functionalized with high value alkylated α-fluorinated alkene motifs under mild conditions.
Submonomer synthesis of peptoids containingtrans-inducingN-imino- andN-alkylamino-glycines
Davern, Carolynn M.,Ison, Elon A.,Lowe, Brandon D.,Proulx, Caroline,Rosfi, Adam
, p. 8401 - 8410 (2021/06/28)
The use of hydrazones as a new type of submonomer in peptoid synthesis is described, giving access to peptoid monomers that are structure-inducing. A wide range of hydrazones were found to readily react with α-bromoamides in routine solid phase peptoid submonomer synthesis. Conditions to promote a one-pot cleavage of the peptoid from the resin and reduction to the correspondingN-alkylamino side chains were also identified, and both theN-imino- andN-alkylamino glycine residues were found to favor thetrans-amide bond geometry by NMR, X-ray crystallography, and computational analyses.
Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones
Luo, Siyi,Peng, Marie,Querard, Pierre,Li, Chen-Chen,Li, Chao-Jun
, p. 13111 - 13117 (2021/09/18)
Copper-catalyzed conjugate addition is a classic method for forming new carbon-carbon bonds. However, copper has never showed catalytic activity for umpolung carbanions in hydrazone chemistry. Herein, we report a facile conjugate addition of hydrazone catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentate ligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.
Switch in Selectivity for Formal Hydroalkylation of 1,3-Dienes and Enynes with Simple Hydrazones
Li, Chao-Jun,Lv, Leiyang,Qiu, Zihang,Yu, Lin
supporting information, p. 6466 - 6472 (2020/03/13)
Controlling reaction selectivity is a permanent pursuit for chemists. Regioselective catalysis, which exploits and/or overcomes innate steric and electronic bias to deliver diverse regio-enriched products from the same starting materials, represents a powerful tool for divergent synthesis. Recently, the 1,2-Markovnikov hydroalkylation of 1,3-dienes with simple hydrazones was reported to generate branched allylic compounds when a nickel catalyst was used. As part of the effort, shown here is that a complete switch of Markovnikov to anti-Markovnikov addition is obtained by changing to a ruthenium catalyst, thus providing direct and efficient access to homoallylic products exclusively. Isotopic substitution experiments indicate that no reversible hydro-metallation across the metal-π-allyl system occurred under ruthenium catalysis. Moreover, this protocol is applicable to the regiospecific hydroalkylation of the distal C=C bond of 1,3-enynes.
Structural studies of 2,5-disubstituted 1,3,4-thiadiazole derivatives from dithioesters under the mild condition: Studies on antioxidant, antimicrobial activities, and molecular docking
Gowda, Kemparaje,Kanchugarkoppal, Rangappa S.,Kempegowda, Mantelingu,Nagarakere, Sandhya C.,Rangappa, Shobith,Swarup, Hassan A.
, (2020/04/27)
A series of 2,5-disubstituted 1,3,4-thiadiazole was synthesized and evaluated for their antioxidant and molecular docking studies. These molecules were efficiently synthesized under mild and inexpensive starting material. Construction of these molecules developed using substituted aldehydes and substituted dithioesters in presence of NCS (N-Chorosuccinimide). The compounds 4a, 4b, 4c, 4f, and 4k showed good antibacterial and antioxidant activity among which, 4k possess excellent antibacterial and antioxidant activity. The results of antioxidant activity studies revealed that compound 4k manifested profound antioxidant potential. The molecular docking study was performed with respective newly synthesized compounds to ascertain the binding mode of 4k with respect to the critical proteins involved in biosynthesis and metabolic pathways.
Efficient Multigram Approach to Acetylenes and CF3-ynones Starting from Dichloroalkenes Prepared by Catalytic Olefination Reaction (COR)
Muzalevskiy, Vasiliy M.,Sizova, Zoia A.,Diusenov, Arstan I.,Shastin, Alexey V.,Nenajdenko, Valentine G.
supporting information, p. 4161 - 4166 (2020/07/13)
A novel approach to terminal acetylenes based on catalytic olefination reaction COR of arylaldehydes to form dichloroalkenes followed by treatment with nBuLi was elaborated. This method is atom economical and displays high yields and effectivity. The corresponding alkynes can be prepared in up to 97 % yield. One pot procedure towards CF3-ynones was elaborated to provide these products in up to 87 % yield starting from dichloroalkenes.
Palladium-Catalyzed Formal Hydroalkylation of Aryl-Substituted Alkynes with Hydrazones
Yu, Lin,Lv, Leiyang,Qiu, Zihang,Chen, Zhangpei,Tan, Ze,Liang, Yu-Feng,Li, Chao-Jun
supporting information, p. 14009 - 14013 (2020/06/10)
We have developed an unprecedented Pd-catalyzed formal hydroalkylation of alkynes with hydrazones, which are generated in situ from naturally abundant aldehydes, as both alkylation reagents and hydrogen donors. The hydroalkylation proceeds with high regio- and stereoselectivity to form (Z)-alkenes, which are more difficult to generate compared to (E)-alkenes. The reaction is compatible with a wide range of functional groups, including hydroxy, ester, ketone, nitrile, boronic ester, amine, and halide groups. Furthermore, late-stage modifications of natural products and pharmaceutical derivatives exemplify its unique chemoselectivity, regioselectivity, and synthetic applicability. Mechanistic studies indicate the possible involvement of Pd-hydride intermediates.
