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A series of oxacalix[2]arene[2]triazines bearing one anionic head such as carboxylate, sulfonate, sulfate, and phosphate were synthesized. With the anionic head and complementary V-shape electron-deficient cavity, these macrocycles can serve as dual building units, and their anion-π directed self-assembly was investigated. The formation of oligomeric aggregates in solution was revealed by nuclear magnetic resonance, dynamic light scattering, and mass spectroscopy. Crystal structures further confirmed chainlike assembly formation directed by anion-π interactions.

Two 2D wavy hexagonal hexahydroxyl cyclotricatechylene (CTC) based COFs, CTC-COF-2 and CTC-COF-3 were synthesized through solvothermal reaction. The bowl-shaped conformation caused CTC skeletons packed in a columnar manner with the same oriented units, thus forming an undulated structure. The gas adsorption properties of CTC-COFs were investigated, which show the potential application abilities in hydrogen storage of CTC-COFs. The introduction of pyrene into CTC-COF-3 makes it a potential semiconducting p-conjugated material.

A series of amino substituted cyclotrianisylene (aCTV)-based covalent organic frameworks (COFs), aCTV-COF1 to aCTV-COF4, have been synthesized. These crystalline analogues showed permanent porosity with BET surface areas from 656 m(2) g(-1) to 1428 m(2) g(-1). With the introduction of methoxy groups and hydroxyl groups at the phenyl linker moieties in aCTV-COF3 and aCTV-COF4, their properties (such as color, gas adsorption, hydrolytic stability and so on) have been influenced to a great extent. The CO2 sorption of aCTV-COF4 has increased significantly, and the H-2 uptake of aCTV-COF3 is obviously higher than those of aCTV-COF1 and aCTV-COF2. Moreover, the introduction of the methoxy and hydroxyl groups has made aCTV-COF3 and aCTV-COF4 have better hydrolytic stability.

Anion-π interactions have been widely studied as new noncovalent driving forces in supramolecular chemistry. However, self-assembly induced by anion-π interactions is still largely unexplored. Herein we report the formation of supramolecular amphiphiles through anion-π interactions, and the subsequent formation of self-assembled vesicles in water. With the π receptor 1 as the host and anionic amphiphiles, such as sodium dodecylsulfate (SDS), sodium laurate (SLA), and sodium methyl dodecylphosphonate (SDP), as guests, the sequential formation of host-guest supramolecular amphiphiles and self-assembled vesicles was demonstrated by SEM, TEM, DLS, and XRD techniques. The intrinsic anion-π interactions between 1 and the anionic amphiphiles were confirmed by crystal diffraction, HRMS analysis, and DFT calculations. Furthermore, the controlled disassembly of the vesicles was promoted by competing anions, such as NO3 (-) , Cl(-) , and Br(-) , or by changing the pH value of the medium.

Five organic complexes are prepared by cocrystallization of tri-[(N-methyl-2-imidazoly)methoxy]cyclotriguiacylene (TMIM-CTG) with corresponding acids. While hydrogen bonds are the basic interactions in the five complexes, the homo-included motifs with C-H center dot center dot center dot pi interactions also control the molecular arrangement except for complex 5. In complex 1, the two dimensional networks contain 1D zigzag chains formed by hydrogen bonding and 1D chains of homo-included CTG motifs. Complex 2 has 2D 4 center dot 8(2) hydrogen bonding networks, and the chains of homomeric inclusion extend the 2D structure to a 3D framework. Complex 3 contains four-membered rings through hydrogen bonds, and the chains of homo-inclusion link the rings to a novel 2D network. In complex 4, hydrogen bonds construct a novel double-layer 2D network, which is extended to a 3D framework by "hand-shake" dimeric homomeric inclusion interactions. Interestingly, there is no homomeric inclusion phenomenon in complex 5 and hydrogen bonds solely connect two components to a chiral (6,3) 2D network.

Highly enantioselective cyanation of β-keto esters using hypervalent iodine(iii) as the electrophilic cyanating reagent induced by cinchona alkaloid-based chiral quaternary ammonium salt was demonstrated. Organic bases, especially DMAP, in the chiral phase-transfer catalysis were used to obtain high ees.

Transition-metal-catalyzed isoquinoline synthesis that profits from the strategy of chelation-assisted C−H activation has flourished over the past decade. By virtue of the directed C−H bond cleavage of imines, amines, amidines, oximes, hydroximoyl halides, hydrazones, or azines, diverse isoquinoline derivatives have been accessed from alkynes, conjugated dienes, or diazo compounds under the catalysis of rhodium, ruthenium, palladium, nickel, or manganese. This digest summarizes the annulation reactions via chelation-assisted C−H activation leading to isoquinolines, isoquinolinium salts, or isoquinoline N-oxides.

Larger-rim functionalized tetraoxacalix[2]arene[2]triazine host molecules were efficiently synthesized through a fragment coupling followed by AlCl3-mediated deprotection/arylation protocol. Substituent effects, functions of counter cations on anion recognition in solution were systematically studied by means of fluorescence and NMR titrations.

Two new 2D COFs were synthesized from triformylcyclotrianisylene, which show not only thermal stability but also hydrolytic stability. CTV-COF-1 with smaller pore size stored a high hydrogen level of 1.3 wt% at low pressure, while CTV-COF-2 with larger pore size showed superior carbon dioxide uptake, up to 250 cm(3) g(-1) at 298 K and 50 bar.

C1-symmetric cyclotriveratrylene analogues 2–8 with various functional groups at one benzene moiety were prepared starting from the selectively demethylated compound 1. Through the chemical resolution, a pair of enantiomers of C1-symmeric compound 1 could be separated with gram scale. Compound 8, which possessed an N-linked imidazolium unit at the upper rim of the macrocyclic skeleton through a methylene linker, was successfully applied to 1,4-Michael addition reaction of alcohol to unsaturated aryl ketone. Its supramolecular catalytic activity as an NHC precursor was demonstrated by the chem-selectivity to aromatic alcohol than alkyl alcohol.

Macrocyclic CTV-Br3 reacted with the linear benzene-1,4-diboronic acid and 1,4-diethynylbenzene via Suzuki and Sonogashira-Hagihara coupling reactions producing the rigid porous materials CTV-CMP-1 and CTV-CMP-2. The porous materials have good thermal and chemical stability. The Brunauer-Emmet-Teller specific surface areas of CTV-CMP-1 and CTV-CMP-2 are 314 and 218 cm2·g−1, respectively. Physical properties of the porous materials were investigated, CTV-CMP-1 showed moderate hydrogen adsorption about 0.81 wt% at 1.13 bar while CTV-CMP-2 showed lower hydrogen adsorption about 0.51 wt%. These materials are analogs to activated carbons which could be potentially used in gas separation and organic compound adsorption.

Two rigid macrocyclic CTV-based porous organic polymers, Click-POP-1 and Click-POP-2, have been synthesized by Click reaction of a cyclotriveratrylene analogue with alkyne groups and aromatic azides in one pot. FTIR, solid 13C NMR and elemental analysis confirmed the formation of the polymers. Both of them possess high thermo-stability which is up to 410 and 900°C, respectively, and moderate hydrogen storage properties with 0.46 wt% at 77 K. Their nitrogen uptake showed type-I isotherm with BET surface areas up to 342 and 317 m2·g−1.

Reaction of isonitriles with 3-(arylamino)isobenzofuran-1(3H)-ones in the presence of a catalytic amount of an octahydro (R)-binol-derived chiral phosphoric acid afforded 3-oxo-2-arylisoindoline-1-carboxamides in high yields with good to high enantioselectivities. An enantioselective Ugi four-center three-component reaction of 2-formylbenzoic acids, anilines, and isonitriles was subsequently developed for the synthesis of the same heterocycle. Mechanistic studies indicate that the enantioselectivity results from the dynamic kinetic resolution of the primary Ugi adduct, rather than from the C-C bond-forming process. The resulting heterocycle products are of significant medicinal importance.

A novel approach to heterocyclic enamines has been developed from the formal ring transformation reaction of lactones. The synthesis comprises consecutive Reformatsky reaction of lactones and mesylation of the resulting mixture of ring-chain tautomers in a one-pot reaction, followed by cyclocondensation reaction with primary amines. The synthetic application of this method was demonstrated by a straightforward preparation of indolizidine compounds via N-(3-bromopropyl)-substituted enamine intermediates. The use of cheap and readily available materials and reagents under very mild conditions renders this formal ring transformation method practical and applicable in the preparation of various heterocyclic enamines that are the precursors for (poly)hydroxylated alkaloid derivatives.

Highly enantioselective cyanation of β-keto esters such as (I), (IV), and (VI) is achieved using hypervalent iodine reagent (II) as electrophilic cyanating reagent and a cinchona alkaloid-based chiral quaternary ammonium salt as catalyst.

In a nonprotic solvent, a (H2O)2(COOH)3(L) supramolecular synthon was found to guide the formation of five new crystal structures together with HPB-3a (1,3,5-tris(4-carboxyphenyl)-2,4,6-tris(4-tert-butylphenyl)benzene). This synthon acted as a 3-connected trigonal planar node (L = acetone) in 1 [(HPB-3a)(H2O)2(acetone)3] or a 4-connected trigonal pyramidal node (L = pyridyl) in 2 [(HPB-3a)(bipy)0.5(H2O)2], 3 [(HPB-3a)(azopy)0.5(H2O)2], 4 [(HPB-3a)(bipy-ete)0.5(H2O)2], and 5 [(HPB-3a)(bipy-eta)0.5(H2O)2] (bipy = 4,4′-bipyridine, azopy = azopyridine, bipy-ete = trans-1,2-bis(4-pyridyl)ethene, bipy-eta = 1,2-bis(4-pyridyl)ethane). The formation of this synthon could be attributed to the C3-symmetry of planar HPB-3a molecules and the hydrophobic interactions between tert-butyl groups. 1 represents a continuously interdigitated 63-hcb layer structure. 2–5 are with the same topology and display amazing 2D homochiral bilayers, which were penetrated in parallel by two others (“above” and “below”) with the opposit...

Various functionalized host molecules and building blocks can be derived from the cone-shaped cyclotriveratrylene (CTV). In this article, we report on the synthesis of CTV-I3 derivatives 3a and 3b and their Sonogashira cross-coupling with various terminal aryl-alkynes, to synthesize CTV-phenylacetylene derivatives in moderate to good yields. In this way, three star-like conjugated dendrimers with rigid macrocyclic cores 4k–m, which showed good photophysical properties, were also synthesized. The band gaps of 4k–m are 3.49, 3.49 and 3.45 eV, and the fluorescence quantum yields are 0.64, 0.78, 0.48 (2-aminopyridine as a standard and excited at 310 nm), respectively. Electrochemical studies revealed their HOMO and LUMO energy levels. Our research disclosed that these CTV dendrimers could potentially be used as host materials in OLEDs.

A series of ( E )-3-benzylidene-4-chromanone derivatives are synthesized, which are substituted with a halogen group on the chromanone moiety in order to control the molecular arrangement in the crystalline state. The stereoselective photoreactions of these compounds in the solid state are examined based on the crystal structures of the reactants and products. All the examples tested undergo photodimerization, except for ( E )-3-benzylidene-6-fluorochroman-4-one. The reactants with β-structures give syn -head-to-head ( syn -HH) products with high selectivity. Only ( E )-6-chloro-3-(4-methylbenzylidene)-chroman-4-one adopted the α-form and gives an anti -head-to-tail ( anti -HT) product.

A novel nanotubular metal–organic framework [Cu3L2(EtOH)(Py)2(H2O)2]·9DEF·8H2O (CTV-Cu) was prepared by assembly of the rigid, trigonal pyramidal ligand tri-(4-carboxy-phenyl)-trimethoxycyclobenzylene (H33L) and Cu(NO3)2·3H2O viasolvothermal reaction. The Cu(II) ions in the crystal serve as square and linear molecular building blocks, thus forming a framework with ternary topology. One single open-ended nanotube contains two identical orthogonally interpenetrated two-nodal nets. This framework exhibits permanent microporosity and relatively high surface area.

An efficient palladium-catalyzed Suzuki-Miyaura coupling method involving the reaction between CTV-Br(3) and a variety of aryl and heteroaryl boronic acids in the presence of indolyl phosphane ligands has been developed. This reaction procedure provided a series of C(3)-symmetric aryl-extended rigid cavitands for the first time. X-ray crystal structure analysis revealed that the phenyl substituted cavitand 5a has much larger rim edges and cavity height. This macrocyclic host adopts a linear head-to-tail "hand-shake" self-inclusion arrangement in the crystalline state. The fluorescence of 5a was considerably quenched upon the addition of C(60), with a binding constant of 78,700 ± 2300 dm(3) mol(-1) and a 1:1 stoichiometry according to the Job's plot. The interaction of C(60) with 5a in the excited state is stronger than that with CTV, which could be attributed to more binding sites in the extended arms of 5a. Moreover, optically active C(3)-symmetric cavitands (+)- and (-)-6 were easily obtained with high efficiency through chemical resolution.

Heteracalixaromatics are a new generation of macrocyclic hosts showing a unique structure and versatile recognition properties towards various guests. Amazingly, the application of heteracalixaromatics as membrane transporters or ion channels has never been explored. We reported herein the elaborated design of a series of oxacalix[2]arene[2]triazine-based derivatives 1-10 and their ion transport properties. Among these compounds, 3, 8-10 can mediate the transport of chloride across the lipid bilayer of EYPC with activity (EC50) ranging from 0.43 to 8.23 μM. These compounds serve as ion carriers during the transport process, and the transport activity is both anion- and cation-dependent, suggesting a Cl(-)/M(+) ion-pair transport model. Structure-activity studies indicate that hydrogen bonding, electron deficiency of the triazine rings, lipophilicity and macrocyclic frameworks are essential for ion transport.

Halogen substituent plays an important role in the crystalline packing of aromatic compounds. The [2+2] photocycloaddition of (E)-3-benzylidene-4-chromanones in the crystalline state was investigated, and halogen substitution has been adopted to organize molecules with proper arrangement for photodimerization. Not halogen bonds, but the electron-withdrawing property of halogen atoms can enhance the face-to-face π–π interactions. Therefore, F, Cl or Br substitution at the para position of phenyl gave rise to almost the same β-structures with face-to-face π-stacking. Only resulted β-structures can undergo photodimerization, which gave the syn-HH (syn-head-to-head) products with high regio-/stereoselectivity.

Three isostructures [C16H8O4·2(CH6N3)·4(H2O)] (1), [C16H10O4·2(CH6N3)·4(H2O)] (2) and [C14H8N2O4·2(CH6N3)·4(H2O)] (3) were prepared by the complexation of guanidinium with 4,4′-(ethyne-1,2-diyl)dibenzoic acid, 4,4′-(ethene-1,2-diyl)dibenzoic acid and 4,4′-(diazene-1,2-diyl)dibenzoic acid, respectively. The strong charge-assisted +N–H⋯O−hydrogen bonds cause the assembly of guanidinium and these different acids following almost the same procedure. The hydrogen-bonded water wire is incorporated in zwitterionic channels of organic salts.

Disulfane-linked bisazacalix[n]pyridines (n=4, 7) were synthesized for the first time using a macrocyclic fragment coupling approach followed by post-macrocyclization photoreaction with ethanethioic acid and hydrolysis under basic conditions. The bis-macrocyclic compounds acted as strong receptors to form 1:1 complex with C60 and C70, giving a binding constant (Ka(1:1)) up to 107000 L·mol−1. The cooperation of two mono-macrocyclic improved binding affinity to fullerenes.

Efficient synthesis and resolution of a series of meta-substituted inherently chiral aminocalix[4]arene derivatives have been described. Consequently, the meta-nitro, bromo and chloro substituted inherently chiral calix[4]arenes could be directly synthesized by the nitration, bromination, and chlorination of the acylating product of aminocalix[4]arene. meta-Cyano and phenyl substituted inherently chiral aminocalix[4]arenes were readily obtained by the nucleophilic substitution reaction or Suzuki coupling reaction from the meta-bromo substituted one under the Pd-catalyzed conditions. For kinetic resolution of the racemic inherently chiral aminocalix[4]arenes, it was found that the electron-withdrawing ability of substituent was helpful to improving the resolution efficiency of the acylation process, and the kinetic resolution could be efficiently applied to the resolution of meta-nitro substituted inherently chiral aminocalix[4]arene, providing (cS)- or (cR)-isomer in up to 95% or 99.9% ee value, respectively, with the corresponding chiral acylating reagent. Moreover, by introduction of the chiral auxiliary, enantiopure antipodes of meta-cyano and phenyl substituted inherently chiral aminocalix[4]arenes could also be readily obtained. These enantiopure aminocalix[4]arenes are potential building blocks for constructing novel chiral receptors and asymmetric catalysts.

A series of monobridged calix[4] arenes 3a-f, cyclic biscalix [4] arenes 4a-f, diametrically bridged at the upper rim with saturated aliphatic diester chains, have been synthesized. The results at dilute conditions show that the percentage of yields of mono-, bis- and oligo-calix[4]arenes are related to the length of the chains. With the shortening of the chains, the percentage of monocalix[4] arenes decreased. All the calix[4] arene moieties are in a cone conformation according to the AB quartet pattern of the methylene protons between the phenolic rings in the 1H NMR spectra.

A new fluorescent compound based on calix [4] arene skeleton was synthesized. Its complexation ability with transition metal ions, such as Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Ag+, was investigated by UV-vis and fluorescent spectra.

The syntheses of chiral calix[4]arene derivatives bearing amino acid residue at the lower rim or upper rim by three different methods were reported.

Catalyzed by FeCl(3) under very mild conditions, tertiary enamides underwent a highly efficient intramolecular enaminic addition reaction to the ketonic carbonyls followed by 1,3-hydroxy rearrangement to produce 5-hydroxy-1H-pyrrol-2(5H)-ones in excellent yields.

Michael-type addition of enamino esters to 3,4,6-tri-O-benzyl-2-nitro-D-glucal under solvent-free conditions formed C-glycosides in excellent yields with high stereoselectivity. Reduction of the nitro group afforded the corresponding bicyclic 2-amino C-glycosides.

A number of homo[2] and homo[4] heterocalix[2]arene[2]triazines were synthesized through a general and good-yielding fragment coupling approach starting from cyanuric halides, aromatic and aliphatic diols, and diamines under very mild reaction conditions. While homo[2] tetraazacalix[2]arene[2]triazine gave a twisted and pinched 1,2-alternate conformer, almost all homo[2] heterocalix[2]arene[2]triazines adopted different partial cone conformations in the solid state. Homo[4] heterocalix[2]arene[2]triazines yielded more diverse conformational structures including partial cone, pinched partial cone, 1,2-alternate and twisted 1,2-alternate, depending on the nature of bridging moieties. On the basis of (1)H NMR spectra, homo[2] and homo[4] heterocalix[2]arene[2]triazines were fluxional macrocycles in solution, and they underwent rapid conformation interconversion at different temperatures. Efficient and straightforward nucleophilic aromatic substitution reaction and palladium-catalyzed cross-coupling reactions on chlorotriazine rings, and the nucleophilic alkylation reaction on the bridging nitrogen atoms led to the construction of various highly functionalized homo heterocalix[2]arene[2]triazine derivatives.

Novel BF2 complex of 3-methylthio enaminones or 3-methylthio enaminoketonatoboron difluorides have been synthesized via reactions of 3-methylthio enaminones with BF3·Et2O in the presence of Et3N in good to excellent yields.

A number of N-substituted azacalix[4]pyrimidines were synthesized by two methods. While straightforward condensation reaction between 4,6-dichloropyrimidine and 4,6-bis(alkylamino)pyrimidines gave identically N-substituted azacalix[4]pyrimidines in low yields, a general and moderate-to-high yielding 1 + 3 macrocyclic fragment coupling reaction afforded azacalix[4]pyrimidines that contained either the same or different N-substituents. Upon treatment with N-bromosuccinimide (NBS) under controlled conditions, methylazacalix[4]pyrimidine was selectively brominated at lower rim to produce mono-, di-, and tribrominated azacalix[4]pyrimidines in good yields. While azacalix[4]pyrimidine derivatives adopted 1,3-alternate conformation in the solid state, the synthesized macrocycles were fluxional in solution, and the interconversion of various conformational structures was rapid relative to the NMR time scale.

Bowl-like tris-[(N-methyl-2-imidazolyl)methoxy]cyclotriguaiacylene (TMIM-CTG) (1) was synthesized and cocrystallized with ethanol, resorcinol, and phloroglucinol to afford three molecular complexes (TMIM-CTG)·(ethanol)3 (2), (TMIM-CTG)·(resorcinol)·(CH3CN)2 (3), and (TMIM-CTG)·(phloroglucinol)·(CH3CN)2 (4), whose structures have been determined by X-ray single crystal analysis. Except for the hydrogen bonds between imidazole of 1 and the hydroxyl group of alcohol/phenols (O−H···N), all crystals contain self-inclusion motifs with cooperative C−H···π interactions which can be considered as the secondary way to extend the primary hydrogen-bonded networks to the frameworks with higher levels. In complex 2, two adjacent TMIM-CTGs form a self-clasping dimer by an edge-to-face C−H···π interaction between the imidazole ring and the benzene ring of CTG, which is further extended to a one-dimensional chain by the π−π interactions between adjacent imidazole rings. The ethanol molecules interact with TMIM-CTGs by hyd...

Functionalized N,O-bridged calix[1]arene[4]pyridines, first examples of the odd-numbered heterocalixaromatics containing mixed heteroatom bridges and mixed aromatic units, have been synthesized from the Pd2(dba)3/dppp-catalyzed 2+3 macrocyclic fragment coupling reaction between readily available staring materials. These novel macrocyclic compounds, which adopted distorted 1,3-alternate conformation in solid state, were powerful host molecules able to form 1:1 complex with fullerene C60 in solution, giving binding constant up to 49,494 M−1.