922-67-8Relevant academic research and scientific papers
Synthesis of 1-methyl-3-oxo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid methyl ester
Aragao, Valquiria,Constantino, Mauricio Gomes,Beatriz, Adilson,Da Silva, Gil Valdo Jose
, p. 1413 - 1418 (2005)
A simple and efficient method for the preparation of 1-methyl-3-oxo-7- oxabicyclo[2.2.1]hept-5-en-2-carboxylic acid methyl ester (1) is described. The first step is a highly regioselective Diels-Alder reaction between 2-methylfuran and methyl-3-bromopropiolate. A remarkably difficult ketal hydrolysis reaction was effected by treatment with HCl, a simple reagent that was shown to be more efficient, in this case, than commonly used more elaborate methods.
Asymmetric synthesis of dihydrocarbazoles through a Friedel-Crafts alkylation/annulation sequential reaction of indoles
Hu, Linfeng,Cao, Weidi,Wang, Kaixuan,Liu, Xiaohua,Feng, Xiaoming
supporting information, p. 13138 - 13141 (2021/12/16)
An enantioselective tandem Friedel-Crafts alkylation/annulation of indoles with diazoacetoacetate enones is realized in one pot. A series of dihydrocarbazoles were obtained in moderate yields with good to excellent ee values by using a RhII/ScIII dual-metallic catalyst system. Control experiments revealed that ScIII is critical to both the alkylation and annulation.
Environment-friendly preparation method of propiolic acid derivatives
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Paragraph 0031-0034, (2020/02/14)
The invention discloses an environment-friendly preparation method of propiolic acid derivatives. The preparation method comprises the following steps: (1) with 2,3-dibromosuccinic acid as a raw material, generating a butynedioic acid salt under alkaline conditions; (2) under an acidic condition, carrying out high-temperature decarboxylation to obtain propiolic acid; and (3) adding corresponding methanol or ethanol into propiolic acid in an extraction solvent, and preparing high-yield propiolate under acidic catalytic conditions under the condition that trimethyl orthoformate or triethyl orthoformate participates in dehydration. In the invention, the propiolic acid preparation method is friendly to environment and high in safety coefficient; and the method provided by the invention can beused for preparing methyl propiolate and ethyl propiolate, and has the advantages of small alcohol consumption, thorough reaction, high yield and easiness in separation.
Carboxylation of terminal alkynes promoted by silver carbamate at ambient pressure
Bresciani, Giulio,Marchetti, Fabio,Pampaloni, Guido
, p. 10821 - 10825 (2019/07/15)
Transition metal carbamates constitute a class of compounds with unique properties, however their catalytic potential has been sparingly explored so far. The easily available silver N,N-dimethylcarbamate, Ag(O2CNMe2), worked as a catalyst in the carboxylation reaction of terminal alkynes with CO2 at atmospheric pressure. Different reaction parameters (solvent, base, temperature, time and the amount of catalyst) were investigated in order to establish the optimal conditions.
Oxidant speciation and anionic ligand effects in the gold-catalyzed oxidative coupling of arenes and alkynes
Hofer, Manuel,De Haro, Teresa,Gómez-Bengoa, Enrique,Genoux, Alexandre,Nevado, Cristina
, p. 8411 - 8420 (2019/09/30)
The mechanism of the gold-catalyzed oxidative cross-coupling of arenes and alkynes has been studied in detail combining stoichiometric experiments with putative reaction intermediates and DFT calculations. Our data suggest that ligand exchange between the alkyne, the Au(i)-catalyst and the hypervalent iodine reagent is responsible for the formation of both an Au(i)-acetylide complex and a more reactive "non-symmetric" I(iii) oxidant responsible for the crucial Au(i)/Au(iii) turnover. Further, the reactivity of the in situ generated Au(iii)-acetylide complex is governed by the nature of the anionic ligands transferred by the I(iii) oxidant: while halogen ligands remain unreactive, acetato ligands are efficiently displaced by the arene to yield the observed Csp2-Csp cross-coupling products through an irreversible reductive elimination step. Finally, the nature of competitive processes and catalyst deactivation pathways has also been unraveled. This detailed investigation provides insights not only on the specific features of the species involved in oxidative gold-catalyzed cross couplings but also highlights the importance of both ancillary and anionic ligands in the reactivity of the key Au(iii) intermediates.
Palladium-Catalyzed Regio- and Stereoselective Coupling-Addition of Propiolates with Arylsulfonyl Hydrazides: A Pattern for Difunctionalization of Alkynes
Liu, Lixin,Sun, Kang,Su, Lebin,Dong, Jianyu,Cheng, Lei,Zhu, Xiaodong,Au, Chak-Tong,Zhou, Yongbo,Yin, Shuang-Feng
supporting information, p. 4023 - 4027 (2018/07/15)
A new pattern for difunctionalization of alkynes via a palladium-catalyzed regio- and stereoselective coupling-addition of propiolates with arylsulfonyl hydrazides is disclosed. The approach enables the synthesis of various highly functionalized (E)-vinylsulfones in satisfactory yields. Arylsulfonyl hydrazides act as both aryl and sulfonyl sources via selective cleavage of Ar(C)-S and S-N bonds, which are simultaneously incorporated onto the terminal carbon atom of an alkyne molecule.
Palladium(II) Acetate-Catalyzed Dual C–H Functionalization and C–C Bond Formation: A Domino Reaction for the Synthesis of Functionalized (E)-Bisindole-2-ones from Diarylbut-2-ynediamides
Li, Guangchen,Zhou, Guangshuai,Zhang-Negrerie, Daisy,Du, Yunfei,Huang, Jianhui,Zhao, Kang
supporting information, p. 3534 - 3540 (2016/11/25)
A domino reaction of palladium(II)-catalyzed dual C–H functionalization with subsequent intramolecular annulation is presented. This method provides a convenient synthesis of a range of symmetrical and unsymmetrical biologically important (E)-bisindole-2-ones under extremely mild reaction conditions – room temperature, green oxidant and no additive. The reaction mechanism is elucidated in light of the yield values as well as additional control experiment results. (Figure presented.).
Synthesis and evaluation of hybrid molecules targeting the vinca domain of tubulin
Gherbovet,Sánchez-Murcia, Pedro A.,García Alvarez,Bignon,Thoret,Gago,Roussi
, p. 3144 - 3154 (2015/03/18)
Some hybrids of vinca alkaloids and phomopsin A, linked by a glycine pattern, have been synthesized in one or two steps, by an insertion reaction and shown to inhibit microtubule assembly. These compounds have been elaborated in order to interact with both the "vinca site" and the "peptide site" of the vinca domain in tubulin. Two out of three hybrids are potent inhibitors of microtubules assembly and they present good cytotoxicity against different cell lines. Molecular modelling studies show that they could bind, within the vinca domain, in similar spatial regions as those of vinca and phomopsin thanks to the flexibility provided by the glycine linker used to elaborate these hybrids. This journal is
Syntheses of α-pyrones using gold-catalyzed coupling reactions
Luo, Tuoping,Dai, Mingji,Zheng, Shao-Liang,Schreiber, Stuart L.
supporting information; experimental part, p. 2834 - 2836 (2011/07/07)
Sequential alkyne activation of terminal alkynes and propiolic acids by gold(I) catalysts yields compounds having α-pyrone skeletons. Novel cascade reactions involving propiolic acids are reported that give rise to α-pyrones with different substitution patterns.
Boronic acid catalysis for mild and selective [3+2] dipolar cycloadditions to unsaturated carboxylic acids
Zheng, Hongchao,McDonald, Robert,Hall, Dennis G.
supporting information; experimental part, p. 5454 - 5460 (2010/09/15)
Herein, the concept of boronic acid catalysis (BAC) for the activation of unsaturated carboxylic acids is applied in several classic dipolar [3 + 2] cycloadditions involving azides, nitrile oxides, and nitrones as partners. These cycloadditions can be used to produce pharmaceutically interesting, small heterocyclic products, such as triazoles, isoxazoles, and isoxazolidines. These cycloadducts are formed directly and include a free carboxylic acid functionality that can be employed for fur-ther transformations, thereby avoiding prior masking or functionalization. In all cases, BAC provides faster reactions, under milder conditions, with much improved product yields and regioselectivities. In some instances, such as triazole formation from the reaction of azides with 2-alkynoic acids, catalysis with ort/io- nitrophenylboronic acid circumvents the undesirable product decarboxylation observed when using thermal activation. By using NMR spectroscopic studies, the boronic acid catalyst was shown to provide activation by a LUMO-lowering effect in the unsaturated carboxylic acid, likely via a monoacylated hemiboronic ester intermediate.
