91-47-4Relevant academic research and scientific papers
On the mechanism of a modified Perkin condensation leading to α-phenylcinnamic acid stereoisomers - Experiments and molecular modelling
Palinko, Istvan,Kukovecz, Akos,Toeroek, Bela,Koertvelyesi, Tamas
, p. 1097 - 1104 (2000)
A modified Perkin condensation leading to α-phenylcinnamic acid stereoisomers affords predominantly or exclusively the (E)-isomer. Reaction duration, temperature, and polarity of the solvent affect the isomeric distribution only to a minor extent. However, geometry optimization of the stereoisomers by semiempirical quantum chemical methods revealed that their thermodynamic stabilities in the absolute minimum are the same. (E)-(Z)-isomerization under the conditions of the Perkin condensation resulted in an equilibrium mixture of nearly 1:1 composition, thus corroborating the results of the computations. Comparing the detailed potential energy maps of the isomers obtained at the semiempirical level of theory may explain the controversy. The (Z)-isomer has a structured potential energy surface with few but well-defined minima, whereas that of the (E)-isomer shows an extended flat plateau enabling this isomer to approach a minimum (which is close to the global one) right after its formation.
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.
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
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.
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.
Method for synthesizing alpha-acrylic acid compound by catalyzing carbon dioxide and alkyne with palladium
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Paragraph 0117-0123, (2020/05/02)
The invention belongs to the technical field of organic synthesis, and discloses a method for synthesizing an alpha-acrylic acid compound by catalyzing carbon dioxide and alkyne with palladium. The preparation method comprises the following steps: adding an alkyne compound, a palladium salt catalyst, alkali, a diphosphine ligand, a silane reducing agent and a solvent into a high-pressure reactionkettle, introducing carbon dioxide, stirring and reacting at 60-120 DEG C, washing a reaction liquid with water for extraction, and separating for purification to obtain the alpha-acrylic acid compound. By using the palladium salt as the catalyst and the diphosphine ligand as the ligand, the method has the characteristics of high yield, single selectivity, wide substrate applicability and the like. In addition, by taking the alkyne compound and carbon dioxide as raw materials in the reaction, the method has the advantages as follows: the raw materials are simple and easily available, the operation is simple and convenient and the atom economy is high.
Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
, p. 2080 - 2088 (2020/02/20)
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
Nickel nanoparticle-catalyzed carboxylation of unsaturated hydrocarbon with CO2 using sulfur-modified Au-supported nickel material
Taniguchi, Takahisa,Saito, Nozomi,Doi, Ryohei,Kimoto, Arato,Hoshiya, Naoyuki,Fujiki, Katsumasa,Shuto, Satoshi,Fujioka, Hiromichi,Arisawa, Mitsuhiro,Sato, Yoshihiro
supporting information, p. 1406 - 1409 (2019/11/05)
A hydrocarboxylation reaction of alkyne or styrene derivatives with CO2 proceeded smoothly by using an air-stable nano-sized nickel catalyst supported on sulfur-modified gold (SANi), giving functionalized acrylic acids and phenylpropionic acids including an anti-inflammatory drug, Flurbiprofen. Notably, SANi could be recycled several times without a significant decrease of the yield.
Anti-neuroinflammatory stilbene analogues as well as preparation method and application thereof
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Paragraph 0028; 0031; 0032, (2018/09/08)
The invention provides anti-neuroinflammatory stilbene analogues as well as a preparation method and an application thereof. The anti-neuroinflammatory stilbene analogues have the structure as followsin the description, wherein R1 is H, halogeno, C1-C5 saturated straight chain alkyl and C1-C3 saturated straight chain alkyl substituted by one or more halogen atoms; and R2 is H, O(CH2)mCH3, halogen, hydroxyl, C1-C5 saturated straight chain alkyl and C1-C3 saturated straight chain alkyl substituted by one or more halogen atoms. According to a lead compound discovery method based on molecular assembly, a new skeleton molecule is designed by assembling two fragments of pyrimidine piperazine and stilbene, and a series of stilbene analogues are synthesized. The compounds have significant anti-neuroinflammatory activity, can permeate blood-brain barrier and can be used as a lead compound in treatment of senile dementia.
