91-48-5Relevant academic research and scientific papers
Hydrocarboxylation of alkynes with formic acid over multifunctional ligand modified Pd-catalyst with co-catalytic effect
Chen, Xiao-Chao,Guo, Lin,Liu, Lei,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Xiao-Li
, p. 322 - 332 (2022/01/06)
Hydrocarboxylation of terminal alkynes with formic acid (FA) was accomplished over a multifunctional ligand (L2) modified Pd-catalyst, advantageous with 100% atom-economy, free use of CO and H2O, mild reaction conditions, and high yields (56–89%) of α,β-unsaturated carboxylic acids with 100% regioselectivity to the branched ones. The multifunctional ligand of L2 as a zwitterion salt containing the phosphino-fragment (-PPh2), Lewis acidic phosphonium cation and sulfonate group (-SO3?), was constructed on the skeleton of 1.1′-binaphthyl-2.2′-diphenyl phosphine (BINAP) upon selective quaternization by 1,3-propanesultone. It was found that L2 conferred to the Pd-catalyst the co-catalytic effect, wherein the phosphino-coordinated Pd-complex was responsible for activation of all the substrates (including CO, FA and alkyne), and the incorporated phosphonium cation was responsible for synergetic activation of FA. The 1H NMR spectroscopic analysis supported that FA was truly activated by the incorporated Lewis acidic phosphonium cation in L2 via “acid-base pair” interaction. The in situ FT-IR spectra demonstrated that, the presence of Ac2O and NaOAc additives in the catalytic amount could dramatically promote the in situ release of CO from FA, which was required to initiate the hydrocarboxylation.
Click amidations, esterifications and one–pot reactions catalyzed by Cu salts and multimetal–organic frameworks (M–MOFs)
Armentano, Donatella,Ferrando-Soria, Jesús,Greco, Rossella,Leyva-Pérez, Antonio,Palomar-De Lucas, Brenda,Pardo, Emilio,Tiburcio, Estefanía
, (2022/03/17)
Amides and esters are prevalent chemicals in Nature, industry and academic laboratories. Thus, it is not surprising that a plethora of synthetic methods for these compounds has been developed along the years. However, these methods are not 100% atom economical and generally require harsh reagents or reaction conditions. Here we show a “spring–loaded”, 100% atom–efficient amidation and esterification protocol which consists in the ring opening of cyclopropenones with amines or alcohols. Some alkyl amines react spontaneously at room temperature in a variety of solvents and reaction conditions, including water at different pHs, while other alkyl amines, aromatic amines and alcohols react in the presence of catalytic amounts of simple Cu2+ salts or solids. A modular reactivity pattern (alkyl amines >> alkyl alcohols >> phenols >> aromatic amines) enables to design orthogonal and one–pot reactions on well–defined catalytic Multimetal–Organic Frameworks (M–MOFs, M= Cu, Ni, Pd), to easily functionalize the resulting cinnamides and cinnamic esters to more complex molecules. The strong resemblance of the amidation and esterification reaction conditions here reported with the copper–catalyzed azide–alkyne cycloaddition (CuAAC) allows to define this fast, clean and flexible protocol as a click reaction.
The synergistic copper/ppm Pd-catalyzed hydrocarboxylation of alkynes with formic acid as a CO surrogate as well as a hydrogen source: An alternative indirect utilization of CO2
Chen, Kai-Hong,He, Liang-Nian,Qiu, Li-Qi,Xia, Shu-Mei,Yang, Zhi-Wen,Yao, Xiang-Yang
supporting information, p. 8089 - 8095 (2021/11/01)
An unprecedented strategy has been developed involving the earth-abundant Cu-catalyzed hydrocarboxylation of alkynes with HCOOH to (E)-acrylic derivatives with high regio- and stereoselectivity via synergistic effects with ppm levels of a Pd catalyst. Both symmetrical and unsymmetrical alkynes bearing various functional groups were successfully hydrocarboxylated with HCOOH, and the modification of a pharmaceutical molecule exemplified the practicability of this process. This protocol employs HCOOH as both a CO surrogate and hydrogen donor with 100% atom economy and it can be viewed as an alternative approach for indirect CO2 utilization. Mechanistic investigations indicate a Cu/ppm Pd cooperative catalysis mechanism via alkenylcopper species as potential intermediates formed from Cu-hydride active catalytic species with HCOOH as a hydrogen source. This bimetallic system involving inexpensive Cu and trace Pd provides a reliable and efficient hydrocarboxylation method to access industrially useful acrylic derivatives with HCOOH as a hydrogen source, and it provides novel clues for optimizing other Cu-H-related co-catalytic systems.
Novel stilbene scaffolds efficiently targetMycobacterium tuberculosisnucleoid-associated protein, HU
Peraman, Ramalingam,Meka, Geethavani,Chilamakuru, Naresh Babu,Kutagulla, Vinay Kumar,Malla, Saloni,Ashby, Charles R.,Tiwari, Amit K.,Yiragamreddy, Padmanabha Reddy
, p. 10683 - 10692 (2021/06/27)
Novel scaffolds of stilbene were identified as inhibitors ofMycobacterium tuberculosisby targeting the nucleoid-associated protein, HU, using molecular docking. Based on the proposed combinatorial libraries I to VI, structures I and III had significantly greater docking binding energy that was comparable to that of the reference ligand, protein HU, fromMycobacterium tuberculosis.Using these docking results, 18 compounds were synthesized, characterized and evaluated forin vitroantitubercular (anti-TB) efficacy in theMycobacterium tuberculosisstrain, H37Rv. Thein vitroscreening results indicated a significant positive correlation between the docking binding efficacy (r2> 0.5) and clogp. Compounds3f,3dand4fwere ranked as top scoring ligands that interacted with amino acids ARG 53, ARG 55, PRO 81, PHE 79, and LYS 13, where the -NO2or -Cl substitution at theparaposition of the 3-phenyl ring was essential for interacting of the HU protein. The hydrogen bonding with ARG 55 and LYS 13 of these compounds was similar to that with the reference ligand that inhibits the HUMtbprotein. Compounds3d,3f, and4fwere evaluated as active leads, with MIC90 values of 21.3, 23.2 and 44.1 μM, respectively. The above mentioned compounds were also evaluated for antibacterial and antifungal efficacy in a panel of selected bacteria and fungi. Compound3dhad efficacy (MIC90: 6.82 μM) inS. aureusandE. coli. Compound3fwas also efficacious inE. coliandA. Niger, with an MIC90 value of 7.42 μM for both microorganisms. The fluoro-phenyl derivatives,3iand4i, were efficacious inC. albicans(MIC90 values of 8.2 and 7.8 μM, respectively) andA. niger(MIC90 values of 4.1 and 3.1 μM, respectively). Our results suggest that substitutions at theparaposition of 3-phenyl acryl derivatives with -NO2and -Cl significantly affected the binding interactions with the HUMtb protein in the docking studies. Furthermore these compounds had antitubercular and antimicrobial efficacy. The substituted phenyl acrylic acid and hydrazides could be inhibitors of the HUMtb protein ofMycobacterium tuberculosis.
Access to α,β-unsaturated carboxylic acids through water-soluble palladium catalyzed hydroxycarbonylation of alkynes using water as the solvent
Gao, Mingjie,Jia, Xiaofei,Lv, Jinhe,Ren, Xinyi,Song, Jiaxin,Xie, Congxia,Zhang, Jinrong,Zhang, Kai,Zhao, Jinyu,Zhou, Ziqin,Zong, Lingbo
, p. 4708 - 4713 (2021/07/26)
A sulfoxantphos modified palladium-catalyzed synthesis of α,β-unsaturated carboxylic acids from alkynes with CO and H2O was described. The atom-economic hydroxycarbonylation of various symmetrical and unsymmetrical alkynes can be achieved with chemo-, stereo-, and regioselectivity, affording the corresponding carboxylic acids in good to excellent yields. Using water as the reaction solvent, the water-soluble palladium catalyst was easily separated from the product and could be reused for 5 cycles.
Palladium catalyzed 8-aminoimidazo[1,2-: A] pyridine (AIP) directed selective β-C(sp2)-H arylation
Mondal, Biswajit,Ghosh, Prasanjit,Kundu, Mrinalkanti,Das, Tapas Kumar,Das, Sajal
, p. 360 - 364 (2021/01/29)
Palladium catalyzed arylation of the inert β-C(sp2)-H bond of carboxylic acid derivatives is reported herein for the first time utilizing 8-aminoimidazo[1,2-a]pyridine (AIP) as an efficacious and new inbuilt 6,5-fused bicyclic removable directing group. This protocol is scalable, exhibits high levels of β-site selectivity and tolerates a broad spectrum of functional groups. This journal is
Method for preparing alpha, beta-unsaturated carboxylic acid compound
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Paragraph 0103-0104; 0527-0531, (2021/05/05)
The invention discloses a method for preparing an alpha, beta-unsaturated carboxylic acid compound, which comprises the following steps: 1) in an atmosphere containing carbon dioxide, heating and reacting a mixture containing hydrosilane and a copper catalyst to obtain a system I; and 2) adding a raw material containing alkyne and a nickel catalyst into the system I in the step 1), and heating to react. The method has the advantages of simple, easily available, cheap and stable raw materials, common, easily available and stable catalyst, mild reaction conditions, simple post-treatment, high yield and the like.
Targeting inflammation with conjugated cinnamic amides, ethers and esters
Fotopoulos, Ioannis,Litina, Dimitra Hadjipavlou,Pontiki, Eleni
, p. 3 - 11 (2020/02/06)
Background: Cinnamic acid is a key intermediate in shikimate and phenylpropanoid pathways. It is found both in free form, and especially in the form of esters in various essential oils, resins and balsams which are very important intermediates in the biosynthetic pathway of several natural products. The cinnamic derivatives play a vital role in the formation of commercially important intermediate molecules which are necessary for the production of different bioactive compounds and drugs. Different substitutions on basic moiety lead to various biological activities. Furthermore, combination of appropriate pharmacophore groups with cinnamic acid derivatives were developed to give hybrids in order to find out promising drug candidates as inhibitors of multiple biological targets associated with inflammation. We found interesting to continue our efforts to design and synthesise three series of novel cinnamic acid-based hybrids: a) nitrooxy esters of cinnamic acid, b) ethers and c) amides of cinnamic acids with arginine, as pleiotropic candidates against multiple targets of inflammation Methods: The synthesis of cinnamic was established by a Knoevenagel-Doebner condensation of the suitable aldehyde either with malonic acid in the presence of pyridine and piperidine, or with phenylacetic acid in the precence of triethylamine in acetic anhydride. The synthesis of the corresponding esters was conducted in two steps. The ethers were synthesized in low yields, with 1,2 – dibromoethane in dry acetone, in the presence of K2CO3, to give oily products. The corresponding cinnamic amides were synthesised in a single step. The synthesised hybrids were tested as lipoxygenase (LOX) and cyclooxygenase (COX) inhibitors in vitro. In silico docking was applied to all the novel derivatives. Several molecular properties of the hybrids were calculated in order to evaluate their drug likeness. Results: A number of esters, ethers and amides of selected cinnamic acids, either phenyl substituted or not, has been synthesised and subjected to modelling studies. The compounds were studied in vitro/in vivo for their inhibitory activities on cox and lox, and as antioxidants. Log P values of all the title compounds except of 3a (5.38) were found to be less than 5 and are in agreement to Lipinski’s rule of five, suggesting satisfactory permeability across cell membrane. The molecular modelling study seems to be in accordance with the experimental results for LOX and COX-2. The result of antioxidant activity for amide 3b supports the anti-lox activity. Compound 5d presents the higher in vivo anti-inflammatory. Conclusion: According to the experimental findings compounds 3b and 5d can be used as lead compounds for the design of new molecules to target inflammation.
Electrocatalytic asymmetric hydrogenation of α,β-unsaturated acids in a PEM reactor with cinchona-modified palladium catalysts
Atobe, Mahito,Fukazawa, Atsushi,Hashimoto, Yasushi,Sato, Yasushi,Tanaka, Kenta
, (2020/04/28)
We have developed an electrocatalytic asymmetric hydrogenation reaction using a proton-exchange membrane (PEM) reactor that employs a polymer electrolyte fuel cell and industrial electrolysis technologies. Reasonable enantioselectivities and excellent current efficiencies were obtained in the asymmetric hydrogenation of α-phenylcinnamic acid under mild conditions without adding a supporting electrolyte. The current density was crucial to achieving the improved results observed.
Stereospecific Electrophilic Fluorocyclization of α,β-Unsaturated Amides with Selectfluor
Fei, Haiyang,Fu, Yao,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian,Wu, Hongmiao,Xu, Zheyuan,Zhu, Lin
, (2020/03/30)
An efficient fluorocyclization of α,β-unsaturated amides through a formal halocyclization process is developed. The reaction proceeds under transition-metal-free conditions and leads to the formation of fluorinated oxazolidine-2,4-diones with excellent regio- and diastereoselectivity. The evaluation of the reaction mechanism based on preliminary experiments and density functional theory calculations suggests that a synergetic syn-oxo-fluorination occurs and is followed by an anti-oxo substitution reaction. The reaction opens a new window in the field of stereospecific fluorofunctionalization.
