Search results
Search for "supramolecular catalyst" in Full Text gives 7 result(s) in Beilstein Journal of Organic Chemistry.
Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis
- Prodip Howlader and
- Michael Schmittel
Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62
- release 89 into solution. Indeed, now the catalysis of addition product 97 was turned ON. While supramolecular transformations are widely recognized [101][102][103], the present example illustrates how a supramolecular catalyst (three-component rotor) transforms itself into a new catalytic machinery and
Graphical Abstract
Figure 1: Butterfly 1 (Figure was reprinted with permission from [45]. Copyright 2012 American Chemical Society. ...
Figure 2: Synthesis of the three-component heteroleptic molecular boat 8 and its use as a catalyst for the Kn...
Figure 3: Synthesis of the two-component triangle 14 and three-component heteroleptic prism 15 [59]. Figure was a...
Figure 4: Catalytic Michael addition reaction using the urea-decorated molecular prism 15 [59].
Figure 5: Self-assembly of two-component tetragonal prismatic architectures with different cavity size. Figur...
Figure 6: Construction of artificial LHS using rhodamine B as an acceptor and 24b as donor generating a photo...
Figure 7: Synthesis of supramolecular spheres with varying [AuCl] concentration inside the cavity. Figure was...
Figure 8: Hydroalkoxylation reaction of γ-allenol 34 in the presence of [AuCl]-encapsulated molecular spheres ...
Figure 9: Two-component heteroleptic triangles of different size containing a BINOL functionality. Figure was...
Figure 10: Asymmetric conjugate addition of chalcone 42 with trans-styrylboronic acid (43) catalyzed by BINOL-...
Figure 11: Encapsulation of monophosphoramidite-Rh(I) catalyst into a heteroleptic tetragonal prismatic cage 47...
Figure 12: (a) Representations of the basic HETPYP, HETPHEN, and HETTAP complex motifs. (b) The three-componen...
Figure 13: Two representative four-component rotors, with a (top) two-arm stator and (bottom) a four-arm stato...
Figure 14: Four-component rotors with a monohead rotator. Figure was adapted with permission from [94]. Copyright ...
Figure 15: (left) Click reaction catalyzed by rotors [Cu2(55)(60)(X)]2+. (right) Yield as a function of the ro...
Figure 16: A supramolecular AND gate. a) In truth table state (0,0) two nanoswitches serve as the receptor ens...
Figure 17: Two supramolecular double rotors (each has two rotational axes) and reference complex [Cu(78)]+ for...
Figure 18: The slider-on-deck system (82•X) (X = 83, 84, or 85). Figure is from [98] and was reprinted from the jo...
Figure 19: Catalysis of a conjugated addition reaction in the presence of the slider-on-deck system (82•X) (X ...
Figure 20: A rotating catalyst builds a catalytic machinery. For catalysis of the catalytic machinery, see Figure 21. F...
Figure 21: Catalytic machinery. Figure was adapted from [100] (“Evolution of catalytic machinery: three-component n...
Figure 22: An information system based on (re)shuffling components between supramolecular structures [99]. Figure ...
Figure 23: Switching between dimeric heteroleptic and homoleptic complex for OFF/ON catalytic formation of rot...
Figure 24: A chemically fueled catalytic system [112]. Figure was adapted from [112]. Copyright 2021 American Chemical S...
Figure 25: (Top) Operation of a fuel acid. (Bottom) Knoevenagel addition [112].
Figure 26: Development of the yield of Knoevenagel product 118 in a fueled system [112]. Figure was reprinted with ...
Figure 27: Weak-link strategy to increased catalytic activity in epoxide opening [119]. Figure was adapted from [24]. C...
Figure 28: A ON/OFF polymerization switch based on the weak-link approach [118]. Figure was reprinted with permissi...
Figure 29: A weak-link switch turning ON/OFF a Diels–Alder reaction [132]. Figure was reprinted with permission fro...
Figure 30: A catalyst duo allowing selective activation of one of two catalytic acylation reactions [133] upon subs...
Figure 31: A four-state switchable nanoswitch (redrawn from [134]).
Figure 32: Sequential catalysis as regulated by nanoswitch 138 and catalyst 139 in the presence of metal ions ...
Figure 33: Remote control of ON/OFF catalysis administrated by two nanoswitches through ion signaling (redrawn...
A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions
- Tommaso Lorenzetto,
- Fabrizio Fabris and
- Alessandro Scarso
Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38
- series of reactions like the carbonyl–ene cyclization of (S)-citronellal preferentially to isopulegol, the water elimination from 1,1-diphenylethanol, the isomerization of α-pinene and β-pinene preferentially to limonene and minor amounts of camphene. The role of the supramolecular catalyst consists in
- tetrahedral polyanionic metal-ligand capsule as supramolecular catalyst, observing lower catalytic activity and product distribution favoring isopulegol but also with large amounts of neoisopulegol and neoisoisopulegol (52%, 32% and 11%, respectively) [51]. More favorable selectivity towards isopulegol was
- efficiently dehydrated by the capsule only in combination with HCl, leading to an acceleration of two orders of magnitude with respect to the same reaction in the absence of the supramolecular catalyst [55]. The group of Tiefenbacher reported about the reactivity of tertiary alcohols bearing a trisubstituted
Graphical Abstract
Scheme 1: Resorcin[4]arene 1 forming the corresponding hexameric capsule 16 and the species used for control ...
Scheme 2: Carbonyl–ene intramolecular cyclization of (S)-citronellal to the corresponding diastereoisomeric c...
Figure 1: 1H NMR spectra in water-saturated CDCl3 except for G. A: [16] (7.5 mM); B: citronellal; C: citronel...
Scheme 3: Dehydration reaction of 1,1-diphenylethanol to 1,1-diphenylethylene.
Figure 2: 1H NMR spectra in water-saturated CDCl3 except for G. A: [16] (7.5 mM); B: 1,1-diphenylethanol; C: ...
Scheme 4: Possible isomerization products from β-pinene and α-pinene.
Figure 3: 1H NMR spectra in water-saturated CDCl3 except for G. A: [16] (7.5 mM); B: α-pinene; C: α-pinene (7...
Figure 4: 1H NMR spectra in water-saturated CDCl3 except for G. A: [16] (7.5 mM); B: β-pinene; C: β-pinene (7...
Figure 5: 1H NMR spectra in water-saturated CDCl3, except for E. A: [16] (7.5 mM); B: β-pinene; C: β-pinene (...
Site-selective reactions mediated by molecular containers
- Rui Wang and
- Yang Yu
Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35
- hydrogenation reaction mediated by a supramolecular catalyst was reported by Raymond, Bergman and Toste in 2019 (Figure 7) [64]. In this example, the supramolecular catalyst was prepared in situ by mixing a rhodium complex with the Ga4L612− cage host G, which had a relatively larger size with pyrene-walled
- more reactive alkynes and allylic alcohols. Both the microenvironment of the supramolecular catalyst and the steric profile of the substrate were responsible for the site-selectivity of hydrogenation. This beautiful work of a supramolecular-mediated catalytic site-selective reaction exhibited the
Graphical Abstract
Figure 1: Site-selective Diels–Alder reaction of anthracene and phthalimide mediated by aqueous organopalladi...
Figure 2: Site-selective Diels–Alder and [2 + 2]-photoaddition reactions between naphthalene and phthalimide ...
Figure 3: Cage host A-mediated selective 1,4-radical addition of o-quinone 10.
Figure 4: Cyclodextrin-mediated site-selective reductions.
Figure 5: Selective reduction of an α,ω-diazide compound mediated by water-soluble cavitand D.
Figure 6: Selective radical reduction of α,ω-dihalides mediated by water-soluble cavitands E and F.
Figure 7: Site-selective hydrogenation of polyenols mediated by supramolecular encapsulated rhodium catalyst.
Figure 8: Site-selective oxidation of steroids using cyclodextrin as the anchoring template.
Figure 9: Site-selective oxidations of linear diterpenoids with the help of cage host A.
Figure 10: Site-selective monoepoxidation of α,ω-dienes mediated by the water-soluble cavitand host E.
Figure 11: Site-selective ring-opening reaction of epoxides mediated by cavitand I with an inwardly directed c...
Figure 12: Site-selective nucleophilic substitution reaction of allylic chlorides mediated by cage host J.
Figure 13: Site-selective monohydrolysis of α,ω-difunctional compounds using deep water-soluble cavitands.
Halides as versatile anions in asymmetric anion-binding organocatalysis
- Lukas Schifferer,
- Martin Stinglhamer,
- Kirandeep Kaur and
- Olga García Macheño
Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145
- display the role of the halide anions and how the predictability of binding properties towards these anions led to the development of a multitude of catalytic concepts and (supramolecular) catalyst systems. Hence, the possibility of employing the catalyst-bound halide anions in the key ion pair complexes
Graphical Abstract
Figure 1: a) Binding interactions in the chloride channel of E. coli. and b) examples of chloride, cyanide, n...
Figure 2: a) H-bond vs anion-binding catalysis and b) activation modes in anion-binding catalysis.
Scheme 1: First proposed anion-binding mechanism in the thiourea-catalyzed acetalization of benzaldehyde.
Scheme 2: a) Thiourea-catalyzed enantioselective acyl-Pictet–Spengler reaction of tryptamine-derived imines 4...
Scheme 3: Proposed mechanism of the thiourea-catalyzed enantioselective Pictet–Spengler reaction of hydroxyla...
Scheme 4: a) Thiourea-catalyzed intramolecular Pictet–Spengler-type cyclization of hydroxylactam-derived N-ac...
Scheme 5: Enantioselective Reissert-type reactions of a) (iso)quinolines with silyl ketene acetals, and b) vi...
Figure 3: Role of the counter-anion: a) Anion acting as a spectator and b) anion participating directly as th...
Scheme 6: Enantioselective selenocyclization catalyzed by squaramide 28.
Scheme 7: Desymmetrization of meso-aziridines catalyzed by bifunctional thiourea catalyst 31.
Scheme 8: Anion-binding-catalyzed desymmetrization of a) meso-aziridines catalyzed by chiral triazolium catal...
Scheme 9: Bis-urea-catalyzed enantioselective fluorination of a) β-bromosulfides and b) β-haloamines by Gouve...
Scheme 10: a) Bifunctional thiourea anion-binding – basic/nucleophilic catalysts. Selected applications in b) ...
Scheme 11: Thiourea-catalyzed enantioselective polycyclization reaction of hydroxylactams 51 through cation–π ...
Scheme 12: Enantioselective aza-Sakurai cyclization of hydroxylactams 56 implicating additional cation–π and L...
Scheme 13: Enantioselective tail-to-head cyclization of neryl chloride derivatives.
Scheme 14: Cation–π interactions in anion binding-catalyzed asymmetric addition reactions: a) addition of indo...
Scheme 15: Bisthiourea catalyzed oxa-Pictet–Spengler reaction of indole-based alcohols and aromatic aldehydes ...
Scheme 16: Anion-binding catalyst development in the enantioselective addition of silyl ketene acetals to 1-ch...
Scheme 17: a) Macrocyclic bis-thiourea catalyst in a diastereoselective glycosylation reaction. b) Competing SN...
Scheme 18: a) Folding mechanism of oligotriazoles upon anion recognition. b) Representative tetratriazole 82 c...
Scheme 19: Switchable chiral tetratriazole catalyst 86 in the enantioselective addition of silyl ketene acetal...
Mechanochemistry of supramolecules
- Anima Bose and
- Prasenjit Mal
Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86
- to be 100% stereospecific under dry mortar and pestle grinding [110]. The hydrogen-bond donor 4,6-dichlororesorcinol was used as the supramolecular catalyst for the transformation in the solid-state. From single crystal X-ray analysis the authors have proved the formation of the 2:2 complex 42 from
- –tert-butylcalix[4]azulene through mortar and pestle grinding of the host and the guest. The structure of the complex was obtained from DFT study. Formation of a 2:2 complex between the supramolecular catalyst and the reagent in the transition state of the [2 + 2]-cycloaddition reaction of 1,2-di
Graphical Abstract
Figure 1: A generalized overview of coordination-driven self-assembly.
Figure 2: Examples of self-assembly or self-sorting and subsequent substitution.
Figure 3: Synthesis of salen-type ligand followed by metal-complex formation in the same pot [55].
Figure 4: Otera’s solvent-free approach by which the formation of self-assembled supramolecules could be acce...
Figure 5: Synthesis of a Pd-based metalla-supramolecular assembly through mechanochemical activation for C–H-...
Figure 6: a) Schematic representation for the construction of a [2]rotaxane. b) Chiu’s ball-milling approach ...
Figure 7: Mechanochemical synthesis of the smallest [2]rotaxane.
Figure 8: Solvent-free mechanochemical synthesis of pillar[5]arene-containing [2]rotaxanes [61].
Figure 9: Mechanochemical liquid-assisted one-pot two-step synthesis of [2]rotaxanes under high-speed vibrati...
Figure 10: Mechanochemical (ball-milling) synthesis of molecular sphere-like nanostructures [63].
Figure 11: High-speed vibration milling (HSVM) synthesis of boronic ester cages of type 22 [64].
Figure 12: Mechanochemical synthesis of borasiloxane-based macrocycles.
Figure 13: Mechanochemical synthesis of 2-dimensional aromatic polyamides.
Figure 14: Nitschke’s tetrahedral Fe(II) cage 25.
Figure 15: Mechanochemical one-pot synthesis of the 22-component [Fe4(AD2)6]4− 26, 11-component [Fe2(BD2)3]2− ...
Figure 16: a) Subcomponent synthesis of catalyst and reagent and b) followed by multicomponent reaction for sy...
Figure 17: A dynamic combinatorial library (DCL) could be self-sorted to two distinct products.
Figure 18: Mechanochemical synthesis of dynamic covalent systems via thermodynamic control.
Figure 19: Preferential formation of hexamer 33 under mechanochemical shaking via non-covalent interactions of...
Figure 20: Anion templated mechanochemical synthesis of macrocycles cycHC[n] by validating the concept of dyna...
Figure 21: Hydrogen-bond-assisted [2 + 2]-cycloaddition reaction through solid-state grinding. Hydrogen-bond d...
Figure 22: Formation of the cage and encapsulation of [2.2]paracyclophane guest molecule in the cage was done ...
Figure 23: Formation of the 1:1 complex C60–tert-butylcalix[4]azulene through mortar and pestle grinding of th...
Figure 24: Formation of a 2:2 complex between the supramolecular catalyst and the reagent in the transition st...
Figure 25: Halogen-bonded co-crystals via a) I···P, b) I···As, and c) I···Sb bonds [112].
Figure 26: Transformation of contact-explosive primary amines and iodine(III) into a successful chemical react...
Figure 27: Undirected C–H functionalization by using the acidic hydrogen to control basicity of the amines [114]. a...
Recent applications of chiral calixarenes in asymmetric catalysis
- Mustafa Durmaz,
- Erkan Halay and
- Selahattin Bozkurt
Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117
- calixarene; organocatalyst; supramolecular catalyst; Introduction The catalysis of organic reactions by macrocyclic host compounds is a longstanding proposed application of supramolecular chemistry and utilizes the use of noncovalent interactions in catalytic systems to achieve higher reaction rates, more
Graphical Abstract
Figure 1: Inherently chiral calix[4]arene-based phase-transfer catalysts.
Scheme 1: Asymmetric alkylations of 3 catalyzed by (±)-1 and (±)-2 under phase-transfer conditions.
Scheme 2: Synthesis of chiral calix[4]arene-based phase-transfer catalyst 7 and structure of O’Donnell’s N-be...
Scheme 3: Asymmetric alkylation of glycine derivative 3 catalyzed by calixarene-based phase-transfer catalyst ...
Figure 2: Calix[4]arene-amides used as phase-transfer catalysts.
Scheme 4: Phase-transfer alkylation of 3 catalyzed by calixarene-triamide 12.
Scheme 5: Synthesis of inherently chiral calix[4]arenes 20a/20b substituted at the lower rim. Reaction condit...
Scheme 6: Asymmetric Henry reaction between 21 and 22 catalyzed by 20a/20b.
Figure 3: Proposed transition state model of asymmetric Henry reaction.
Scheme 7: Synthesis of enantiomerically pure phosphinoferrocenyl-substituted calixarene ligands 27–29.
Scheme 8: Asymmetric coupling reaction of aryl boronates and aryl halides in the presence of calixarene mono ...
Scheme 9: Asymmetric allylic alkylation in the presence of calix[4]arene ligand (S,S)-29.
Figure 4: Structure of inherently chiral oxazoline calix[4]arenes applied in the palladium-catalyzed Tsuji–Tr...
Scheme 10: Asymmetric Tsuji–Trost reaction in the presence of calix[4]arene ligands 36–39.
Figure 5: BINOL-derived calix[4]arene-diphosphite ligands.
Scheme 11: Asymmetric hydrogenation of 41a and 41b catalyzed by in situ-generated catalysts comprised of [Rh(C...
Figure 6: Inherently chiral calix[4]arene 43 containing a diarylmethanol structure.
Scheme 12: Asymmetric Michael addition reaction of 44 with 45 catalyzed by 43.
Figure 7: Calix[4]arene-based chiral primary amine–thiourea catalysts.
Scheme 13: Asymmetric Michael addition of 48 with 49 catalyzed by 47a and 47b.
Scheme 14: Enantioselective Michael addition of 51 to 52 catalyzed by calix[4]arene thioureas.
Scheme 15: Synthesis of calix[4]arene-based tertiary amine–thioureas 54–56.
Scheme 16: Asymmetric Michael addition of 34 and 57 to nitroalkenes 49 catalyzed by 54b.
Scheme 17: Synthesis of p-tert-butylcalix[4]arene bis-squaramide derivative 64.
Scheme 18: Asymmetric Michael addition catalyzed by 64.
Scheme 19: Synthesis of chiral p-tert-butylphenol analogue 68.
Figure 8: Novel prolinamide organocatalysts based on the calix[4]arene scaffold.
Scheme 20: Asymmetric aldol reactions of 72 with 70 and 71 catalyzed by 69b.
Scheme 21: Synthesis of p-tert-butylcalix[4]arene-based chiral organocatalysts 75 and 78 derived from L-prolin...
Scheme 22: Synthesis of upper rim-functionalized calix[4]arene-based L-proline derivative 83.
Scheme 23: Synthesis and proposed structure of Calix-Pro-MN (86).
Figure 9: Calix[4]arene-based L-proline catalysts containing ester, amide and acid units.
Scheme 24: Synthesis of calix[4]arene-based prolinamide 92.
Scheme 25: Calixarene-based catalysts for the aldol reaction of 21 with 70.
Scheme 26: Asymmetric aldol reactions of 72 with cyclic ketones catalyzed by calix[4]arene-based chiral organo...
Figure 10: A proposed structure for catalyst 92 in H2O.
Scheme 27: Synthetic route for organocatalyst 98.
Scheme 28: Asymmetric aldol reactions catalyzed by 99.
Figure 11: Proposed catalytic environment for catalyst 99 in the presence of water.
Scheme 29: Asymmetric aldol reactions between 94 and 72 catalyzed by 55a.
Scheme 30: Enantioselective Biginelli reactions catalyzed by 69f.
Scheme 31: Synthesis of calix[4]arene–(salen) complexes.
Scheme 32: Enantioselective epoxidation of 108 catalyzed by 107a/107b.
Scheme 33: Synthesis of inherently chiral calix[4]arene catalysts 111 and 112.
Scheme 34: Enantioselective MPV reduction.
Scheme 35: Synthesis of chiral calix[4]arene ligands 116a–c.
Scheme 36: Asymmetric MPV reduction with chiral calix[4]arene ligands.
Scheme 37: Chiral AlIII–calixarene complexes bearing distally positioned chiral substituents.
Scheme 38: Asymmetric MPV reduction in the presence of chiral calix[4]arene diphosphites.
Scheme 39: Synthesis of enantiomerically pure inherently chiral calix[4]arene phosphonic acid.
Scheme 40: Asymmetric aza-Diels–Alder reactions catalyzed by (cR,pR)-121.
Scheme 41: Asymmetric ring opening of epoxides catalyzed by (cR,pR)-121.
Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent
- Kohei Koyanagi,
- Yoshinori Takashima,
- Takashi Nakamura,
- Hiroyasu Yamaguchi and
- Akira Harada
Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244
- distributed polymers. In the presence of 1,6-hexanediol (C6 diol) which works as a competitive molecule by being included in the α-CD cavity, the reaction yield was lower than that without C6 diol. Keywords: cyclodextrin; radical polymerization; RAFT polymerization; substrate recognition site; supramolecular
- catalyst; Introduction The folding of proteins in biological systems, the replication of DNA, and specific substrate recognition by enzymes play important roles in forming supramolecular structures, achieving functions, and maintaining life [1][2][3][4][5][6]. The crystal structures of RNA polymerase, DNA
Graphical Abstract
Figure 1: Preparation scheme of α-CD-CTA.
Figure 2: Crystal structure of α-CD with N,N-dimethylacrylamide (DMA). (a) The structure of an 1:1 inclusion ...
Figure 3: Time-conversion curves (a), kinetic plots (b) and plots of number-average molecular weight (Mn) ver...
Figure 4: Proposed polymerization mechanism for a water-soluble vinyl monomer with α-CD-CTA as a chain transf...
