60335-71-9Relevant articles and documents
Ligand-Directed Conformational Control over Porphyrinic Zirconium Metal-Organic Frameworks for Size-Selective Catalysis
Yang, Liting,Cai, Peiyu,Zhang, Liangliang,Xu, Xiaoyi,Yakovenko, Andrey A.,Wang, Qi,Pang, Jiandong,Yuan, Shuai,Zou, Xiaodong,Huang, Ning,Huang, Zhehao,Zhou, Hong-Cai
supporting information, p. 12129 - 12137 (2021/08/23)
Zirconium-based metal-organic frameworks (Zr-MOFs) have aroused enormous interest owing to their superior stability, flexible structures, and intriguing functions. Precise control over their crystalline structures, including topological structures, porosity, composition, and conformation, constitutes an important challenge to realize the tailor-made functionalization. In this work, we developed a new Zr-MOF (PCN-625) with a csq topological net, which is similar to that of the well-known PCN-222 and NU-1000. However, the significant difference lies in the conformation of porphyrin rings, which are vertical to the pore surfaces rather than in parallel. The resulting PCN-625 exhibits two types of one-dimensional channels with concrete diameters of 2.03 and 0.43 nm. Furthermore, the vertical porphyrins together with shrunken pore sizes could limit the accessibility of substrates to active centers in the framework. On the basis of the structural characteristics, PCN-625(Fe) can be utilized as an efficient heterogeneous catalyst for the size-selective [4 + 2] hetero-Diels-Alder cycloaddition reaction. Due to its high chemical stability, this catalyst can be repeatedly used over six times. This work demonstrates that Zr-MOFs can serve as tailor-made scaffolds with enhanced flexibility for target-oriented functions.
Synthetic method of aromatic rose ether perfume
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Paragraph 0031-0042, (2020/07/24)
The invention discloses a synthesis method of an aromatic rose ether perfume, which comprises the following steps: with benzaldehyde and isopentenol as raw materials and non-strong protonic acid or Lewis acid as a catalyst, completely carrying out a reaction in an inert non-protonic solvent at reflux temperature, and carrying out after-treatment on the obtained reaction mixed solution to obtain 4-methyl-2-phenyl-dihydropyran. According to the method disclosed by the invention, a mild catalyst is adopted; benzaldehyde or isopentenol with the equivalent weight smaller than 1 is used, a solvent azeotropic with water is used for removing water generated in the reaction, the reaction selectivity is improved, and the reaction molar yield can reach about 90%; the method has the advantages of being economical, environmentally friendly, easy and convenient to implement and high in yield and is suitable for large-scale industrial production.
AlCl3 catalyzed oxa-Diels-Alder reaction of aromatic aldehydes with simple dienes
Jian, Wujun,Qian, Bo,Bao, Hongli,Li, Daliang
supporting information, p. 4039 - 4044 (2017/06/29)
A highly regioselective and diastereoselective oxa-Diels-Alder reaction catalyzed by AlCl3 has been developed. This reaction is efficient and characterized by good functional group compatibility, F, Cl, CN, NO2, OMe and thiophenyl groups are tolerated. A Lewis acid catalyzed concerted cycloaddition mechanism is proposed based on the results.
Nanoporous iron(III) porphyrin frameworks: an efficient catalyst for [4+2] cycloaddition reactions of unactivated aldehydes with a diene
Singh, Manoj Kumar,Bandyopadhyay, Debkumar
, p. 6358 - 6363 (2016/07/16)
The one pot conversion of several unactivated aldehydes with a diene to their corresponding [4+2] cycloaddition products has been studied using newly synthesized nanoporous iron(iii) porphyrin frameworks as catalysts. The heterogeneous catalysts have been synthesized from 5,10,15,20-tetrakis(4-cyanophenyl)porphyrinato iron(iii) chloride (PFe·X) with the help of Pinnar type synthesis. The catalytic activity of the monomeric catalyst (PFe·X) vs. that of the new nanoporous catalysts (1·X) where X = Cl-, BF4-etc. in the reaction of dienes and aldehydes were then compared. The structure of the catalysts was investigated using different characterization techniques including Fourier transform infrared spectroscopy (FT-IR), CHN, atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM) and the BET surface area which was measured via a physisorption study of N2 at 77 K. The reaction parameters determining yield, including the quantity of the catalyst and the solvent, were optimized to afford the hetero Diels-Alder product efficiently. It was observed that the nanoporous catalysts (1·X) were much superior to the monomeric (PFe·X) catalysts at giving selective products in high yields. Secondly, the new catalysts remained active for at least 8 cycles without any observable decay in their catalytic ability. Attempts are made to rationalize the results by considering the nature of X and the BET surface area of the 1·X catalysts.
Metalloporphyrin-Based Hypercrosslinked Polymers Catalyze Hetero-Diels–Alder Reactions of Unactivated Aldehydes with Simple Dienes: A Fascinating Strategy for the Construction of Heterogeneous Catalysts
Dou, Zhiyu,Xu, Li,Zhi, Yongfeng,Zhang, Yuwei,Xia, Hong,Mu, Ying,Liu, Xiaoming
supporting information, p. 9919 - 9922 (2016/07/19)
We describe a novel and intriguing strategy for the construction of efficient heterogeneous catalysts by hypercrosslinking catalyst molecules in a one-pot Friedel–Crafts alkylation reaction. The new hypercrosslinked polymers (HCPs) as porous solid catalysts exhibit the combined advantages of homogeneous and heterogeneous catalysis, owing to their high surface area, good stability, and tailoring of catalytic centers on the frameworks. Indeed, a new class of metalloporphyrin-based HCPs were successfully synthesized using modified iron(III) porphyrin complexes as building blocks, and the resulting networks were found to be excellent recyclable heterogeneous catalysts for the hetero-Diels–Alder reaction of unactivated aldehydes with 1,3-dienes. Moreover, this new strategy showed wide adaptability, and many kinds of homogeneous-like solid-based catalysts with high catalytic performance and excellent recyclability were also constructed.
Carbocation Catalysis: Oxa-Diels-Alder Reactions of Unactivated Aldehydes and Simple Dienes
El Remaily, Mahmoud Abd El Aleem Ali Ali,Naidu, Veluru Ramesh,Ni, Shengjun,Franzén, Johan
supporting information, p. 6610 - 6614 (2015/10/29)
The versatility of the trityl cation (TrBF4) as a highly efficient Lewis acid organocatalyst is demonstrated in the oxa-Diels-Alder reaction of various unactivated aromatic and aliphatic aldehydes and simple unactivated dienes, such as isoprene and 2,3-dimethylbutadiene. The transformation proceeds smoothly to give 3,6-dihydropyrane adducts in high to moderate yields with catalyst loadings down to 1.0 mol-% under mild reaction conditions. In contrast to most previously reported strategies, this protocol does not require substrate functional group activation, neither by electron-deficient aldehydes (2-oxo aldehydes) or electron-rich dienes (methoxy or amino-butadiene).
Cationic iron(III) porphyrin-catalyzed [4 + 2] cycloaddition of unactivated aldehydes with simple dienes
Fujiwara, Kyohei,Kurahashi, Takuya,Matsubara, Seijiro
supporting information; experimental part, p. 5512 - 5515 (2012/05/20)
Cationic iron(III) porphyrin was found to be an efficient catalyst for the highly chemoselective hetero-Diels-Alder-type reaction of aldehydes with 1,3-dienes. The catalyzed process did not require the use of electron-deficient aldehydes such as glyoxylic acid derivatives or activated electron-rich 1,3-dienes such as Danishefsky's diene and Rawal's diene. The high functional group tolerance and robustness of the catalyst were demonstrated. Further, the potential utility of the catalyst was demonstrated by performing the cycloaddition in the presence of water and by carrying out cycloaddition of an unactivated ketone such as cyclohexanone with a diene.
An efficient synthesis of dihydro- and tetrahydropyrans via oxonium-ene cyclization reaction
Bondalapati, Somasekhar,Reddy, Udagandla C.,Saha, Pipas,Saikia, Anil K.
experimental part, p. 3428 - 3438 (2011/06/20)
An efficient method has been developed for the synthesis of 2,3-dihydropyrans and 4-methylenetetrahydropyrans from aldehydes and substituted homoallyl alcohols in benzene mediated by boron trifluoride etherate in good yields. The reaction proceeds via oxonium-ene reaction.
Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation(allylation)-ring closing metathesis-oxidation sequence
Marco, J. Alberto,Carda, Miguel,Rodríguez, Santiago,Castillo, Encarnación,Kneeteman, María N.
, p. 4085 - 4101 (2007/10/03)
Nucleophilic C-vinylation and C-allylation of aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl or homoallyl ethers, respectively. Ring-closing metathesis of these compounds afforded in many cases cyclic ethers (dihydrofurans and dihydropyrans, respectively) bearing disubstituted and trisubstituted C=C bonds. These were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones. Reasons for the observed failures are presented and discussed.
Diels-alder reaction of aldehydes with simple dienes
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, (2008/06/13)
The invention concerns Diels-Alder reactions between non-activated aldehydes RCHO in which R is a C1-C10 aliphatic group or phenyl group, which is unsubstituted or substituted with one or more C1-C5 alkyl groups or one other functional group, with simple aliphatic dienes R1CH=CR2-CR3=CHR4 in which R1-R4 are H or C1-C5 alkyl groups using as a catalyst a perfluorinated organic sulphonic acid or a Br+E,uml o+EE nsted acid derivative thereof. The reaction leads to dihydropyrans of the structure below in which R1-R4 have the meaning indicated above. The preferred perfluorinated organic sulfonic acids are perfluorooctanesulphonic acid, triflic acid, Nafion or a Br+E,uml o+EE nsted acid derivative of triflic acid. The preferred aldehydes are those wherein R is a C2-C6 aliphatic group or a phenyl group which is unsubstituted or mono-substituted with C1-C3 alkyl or with 4-Cl, 4-nitro or 3-methoxy. The preferred dienes are those wherein the groups R1-R4 are H or methyl.