Supramolecular calixarene-based catalytic systems in the Wacker-oxidation of higher alkenes

Максимов, А. Л.; Buchneva, Tatyana S.; Караханов, Э. А.

doi:10.1016/j.molcata.2004.03.024

Cited by 29 publications

(24 citation statements)

References 37 publications

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“…8, 23 The data on non 1 ene hydroformylation in the pres ence of ligands L 1 -L 7 under identical conditions are presented in Table 1. It is seen that the catalytic systems based on calix [6]arenes are characterized by the highest activity. They have larger hydrophobic cavities than calix [4]arenes.…”

Section: Methodsmentioning

confidence: 99%

“…Comparing the molecular models of the inclusion complexes of the catalysts based on p tert butylcalix [6] arenehexaphosphinite L 4 with arylalkenes ( Fig. 6), one can suggest that the acceleration of the catalytic pro cess is favored by an additional immobilization of the bulky substrate in the calixarene cavity, due to which the transition state of the reaction is more easi ly achieved.…”

Section: Methodsmentioning

confidence: 99%

“…[19][20][21][22] An increase in the steric volume of the ligand was found to increase the yield of aldehydes with the normal carbon chain, whereas the enhancement of the electron accepting properties favors the formation of the catalytically active form of the rhodium complex due to the compensation of an excessive negative charge on the metal atom. Therefore, we synthesized the organo phosphorus ligands from calix [4] and calix [6]arenes L 1 -L 7 with different electron donating properties, mac rocycle size, and orientation of the complexing groups relative to the calixarene platform.…”

Section: Hydroformylation Of Unsaturated Compounds Using Calixarene Bmentioning

confidence: 99%

“…p tert Butylcalix [6]arenediphosphite L 6 and calix [6] arenediphosphite L 7 were synthesized by the reaction of the corresponding calixarenes with phosphorus trichlo ride in toluene in the presence of triethylamine (Scheme 3). Mass spectrometric data (ЕSI) indicated that the reac tion of calixarene with PCl 3 afforded dimeric compounds along with diphosphites L 6 and L 7 : the mass spectrum contains two pairs of signals with equal intensity at m/z 1029, 2058 and 693, 1386 for L 6 and L 7 , respectively.…”

Section: Hydroformylation Of Unsaturated Compounds Using Calixarene Bmentioning

confidence: 99%

“…This approach provides wide possibilities for design of new highly active metal com plex catalysts with high substrate, regio , and chemiose lectivity. [1][2][3][4][5][6][7] Various classes of receptor molecules, particularly, cyclodextrins, calixarenes, and dendrimers ( Fig. 1), are used for the design of supramolecular catalysts.…”

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Design of supramolecular metal complex catalytic systems for petrochemical and organic synthesis

et al. 2008

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Specific features of the behavior of the supramolecular metal complex catalysts based on calix arenes, cyclodextrins, and dendrimers in the reactions of hydroformylation, Wacker oxidation, hydroxylation of aromatics, 2 naphthol coupling, and oxidative coupling of styrenes and benzene were studied. The factors affecting the catalytic activity and selectivity are discussed.The control of selectivity in catalytic systems is one of the main problems in petrochemical and organic synthe ses. In the recent years researchers are interested in su pramolecular catalysis, the phenomena based on the use of substances capable of forming host-guest inclusion complexes with various organic compounds as compo nents of catalytic systems. This approach provides wide possibilities for design of new highly active metal com plex catalysts with high substrate, regio , and chemiose lectivity. 1-7Various classes of receptor molecules, particularly, cyclodextrins, calixarenes, and dendrimers ( Fig. 1), are used for the design of supramolecular catalysts. 2-4,8,9Cyclodextrins are macrocyclic compounds formed by α D glucopyranose. Calixarenes are the compounds syn thesized by the condensation of phenols and aldehydes of diverse structure. The selective functionalization of the upper and lower rims of these macrocycles by hetero atomic groups can form a molecular system bearing sev eral binding sites and in this way create catalysts capable of molecular recognition. One more type of molecular receptors is presented by dendrimers, which are polymer molecules with regular branched structures and can be considered as unique monomolecular globular micelles. Due to noncovalent interactions between several frag ments of the polymer chain and an organic molecule, dendrimers can be selectively bonded to the substrate, thus enhancing the efficiency and selectivity of the im mobilized metal complex catalyst. 3,9-18 Location of the active sites at the ends of the dendrimer branches can minimize diffusional restrictions, and the den drimers become good models for studying specific fea tures of the behavior of the immobilized homogeneous systems.Design of the catalysts on the basis of receptor mole cules can be performed via two routes: (1) using the target chemical modification of the receptor acting as a ligand;(2) using the molecular imprinting method. 3 The im printing process proceeds as follows. At the first step a receptor molecule interacts with a template molecule to form a host-guest inclusion complex (Scheme 1). The structure that formed is immobilized by binding agents containing two and more functional groups. At the Scheme 1

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Hydroformylation Of Unsaturated Compounds Using Calixarene Bmentioning

confidence: 99%

Section: Hydroformylation Of Unsaturated Compounds Using Calixarene Bmentioning

confidence: 99%

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Design of supramolecular metal complex catalytic systems for petrochemical and organic synthesis

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Wacker Oxidation

2010

Comprehensive Organic Name Reactions and Reagents

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This reaction is the industrial production of acetaldehyde by the oxidation of ethylene with oxygen in the presence of aqueous acidic solution of palladium chloride and cupric chloride and is generally known as the Hoechst‐Wacker process, or simply as the Wacker process. This reaction is generally used to convert the terminal olefins into methyl ketones with oxygen or air as oxidant, and such reaction is known as the Wacker–Hoechst oxidation and the combination of palladium chloride and cupric chloride is known as the Wacker catalyst. In addition, the oxidation of olefins with a heteroatom adjacent to the olefinic functionality may change the reaction path, yielding alternative products. The study finds that such cyclization occurs with high syn ‐stereochemistry in regard to palladium and oxygen in the absence of chloride, but proceeds mainly in anti fashion in the presence of a chloride. This reaction has been extensively modified by the application of a reverse phase‐transfer catalyst. This reaction has wide application in organic synthesis.

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Molecular Recognition and Catalysis: from Macrocyclic Receptors to Molecularly Imprinted Metal Complexes

Караханов

Karapetyan

Kardasheva

et al. 2006

Macromolecular Symposia

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The results of studying a number of reactions catalyzed by several types of soluble macromolecular catalytic systems capable of selectively binding organic substrates, namely, modified cyclodextrins, calixarenes and dendrimers are presented. The use of modified cyclodextrins as components of a catalytic system in the phenol and benzene hydroxylation by hydrogen peroxide allows one both to increase the catalytic activity and to change significantly the chemical selectivity. Phosphorilated calixarene -Rh catalytic systems was found to be catalytically active in hydroformylation of linear alkenes C 7 -C 12 . The results of experiments on the oxidation of C 7 -C 16 alkenes show that, when the ligand is the dendrimer molecule, the fraction of forming methyl ketones substantially increases for the substrates C 7 -C 9 . For the higher alkenes, this effect is not observed.

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Supramolecular calixarene-based catalytic systems in the Wacker-oxidation of higher alkenes

Cited by 29 publications

References 37 publications

Design of supramolecular metal complex catalytic systems for petrochemical and organic synthesis

Design of supramolecular metal complex catalytic systems for petrochemical and organic synthesis

Wacker Oxidation

Molecular Recognition and Catalysis: from Macrocyclic Receptors to Molecularly Imprinted Metal Complexes

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