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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.

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.

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.

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.

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.

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.

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.

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.

Catalyzed by the Rhodococcus erythropolis AJ270 whole cell catalyst in neutral aqueous buffer at 30 degrees C, a number of racemic 1-benzylazetidine-2-carbonitriles, trans-1-benzyl-4-methylazetidine-2-carbonitrile, and 1-benzyl-2-methylazetidine-2-carbonitrile and their amide substrates underwent efficient and enantioselective biotransformations to afford the corresponding azetidine-2-carboxylic acids and their amide derivatives in excellent yields with ee up to99.5%. The overall excellent enantioselectivity of the biocatalytic reactions stemmed from a combined effect of a very active but virtually nonenantioselective nitrile hydratase and a high R-enantioselective amidase involved in microbial whole cells. The synthetic applications have been demonstrated by the nucleophilic ring-opening reactions of azetidiniums of the resulting chiral azetidine-2-carbox amide derivatives for the preparation of alpha,gamma-diamino, alpha-phenoxy-gamma-amino, and alpha-cyano-gamma-amino carboxamides. The intramolecular CuI-catalyzed cross-coupling reaction for the synthesis of azetidine-fused 1,4-benzodiazepin-2-one derivative was also presented.

A series of novel N,O-type chiral ligands derived from enantiopure inherently chiral calix[4]arenes containing quinolin-2-yl-methanol moiety in the cone or partial-cone conformation have been synthesized and characterized. Moreover, they have been applied to the catalytic asymmetric addition of diethylzinc to benzaldehyde, which represents the first example that the inherently chiral calixarene can be used as the chiral ligands for the catalytic asymmetric synthesis.

The Borromean system, which contains nontrivial three ring links (no ring is interlocked to another without the help of the third one), is a very intriguing pattern of crystal entanglements, because of the topological complexity, structural integrity, and aesthetic beauty. Herein we report the rational construction of Borromean three-fold 2D-2D entangled layers and n-Borromean 2D-3D entangled infinite layers with pure organic supramolecular synthons based on hydrogen-bond-directed self assembly.

Rhodococcus erythropolis AJ270, a nitrile hydratase/amidase-containing microbial whole cell catalyst, is able to catalyze the hydrolysis of a number of β-hydroxy and β-alkoxy nitriles under very mild conditions. Both the efficiency and enantioselectivity of the biocatalysis, however, were strongly dependent upon the structures of both nitrile and amide substrates. When biotransformations of racemic 3-hydroxy-3-phenylpropionitrile and 2-hydroxymethyl-3-phenylpropionitrile gave low enantioselectivity, their O-methylated isomers underwent highly efficient and enantioselective biocatalytic reactions to afford highly enantioenriched β 2 - and β 3 -hydroxy amide and acid derivatives in excellent yield. The study has provided an example of simple and very convenient substrate engineering method to increase the enantioselectivity of the biocatalytic reaction.

[structure: see text]. Catalyzed by CuI/N,N-dimethylglycine, oxiranecarboxamides underwent a highly efficient and stereoselective N-vinylation reaction with (Z)-1-aryl-2-bromoethenes to afford the corresponding enamides. The method has been applied to a straightforward synthesis of (-)-(2R,3S)-SB204900, the enantiomer of the natural product. Following a hypothetic biomimetic pathway, both (+)-(5R,6S)-xi-Clausenamide and (-)-(5R,6S)-balasubramide have been efficiently synthesized for the first time through the unprecedented intramolecular 8-endo-epoxy-arene cyclization of (Z)-N-(phenylvinyl)oxiranecarboxamides.

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.

A series of inherently chiral calix[4]arenes with cone and partial cone conformations and with crown ether moieties of variable size have been readily synthesized. By taking advantage of the carboxy appendage on the lower rim, these were condensed with the chiral auxiliary (S)-BINOL to form diastereomers which, in most cases, could be separated by preparative TLC, or more desirably, by column chromatography on silica gel (diastereomeric excess >99 % based on HPLC analysis). Seven enantiopure antipodes of inherently chiral calix[4]crowns were obtained after hydrolysis. It has been found that both the size of the crown moiety and alkylation of the last phenolic hydroxy group (accompanied with or without a change in the conformation) affect the separation of the diastereomers.

Chiral calix[5]arenes, (R)- and (S)-1 and (R)- and (S)-2, were synthesized. The complexation properties of binary hosts [(R)-1·Cu2+] and [(S)-1·Cu2+] towards carbohydrates were explored. The fluorescent titration experiments show that they can selectively recognize d -(+)-gluconic acid δ-lactone 4 with the association constant K R ′ = 4 . 45 ( ± 0 . 20 ) × 10 4 M - 1 and K S ′ = 1 . 81 ( ± 0 . 20 ) × 10 4 M - 1 between various carbohydrates in a MeCN–H2O (4:1 v/v) solution of HEPES buffer (0.3 mM, pH 7.4), respectively.

Enantiopure inherently chiral calix[5]arenes were successfully prepared by separation of their (R)-BINOL diastereomeric derivatives of the corresponding racemates by column chromatography instead of HPLC. A new type of inherently chiral calix[5]arene was obtained.

Heterocyclic ketene aminals reacted with ethyl 2-(bromomethyl)benzoate in refluxing acetonitrile to afford the C-benzylated products that underwent intramolecular cyclocondensation reaction to produce e-lactam fused heterocyclic compounds. The heterocyclic ring size effect on the reaction was discussed.

This unusual reaction is performed in tetrahydrofuran which is split during the reaction in an unprecedented manner under conditions used, leading to the formation of two geminal C—C bonds via C—H and C—O cleavage.

Regulated assemblies from vesicles to micelles based on 1,3-alternate oxacalix[2]arene[2]triazine amphiphilic molecules were reported. The vesicular entities were responsive to anions and followed the selectivity in the order NO3− > Cl− > Br− > ClO4−, driven by cooperative anion–π interactions and hydrogen bonding.

Described herein is a manganese-catalyzed dehydrogenative [4+2] annulation of NH imines and alkynes, a reaction providing highly atom-economical access to diverse isoquinolines. This transformation represents the first example of manganese-catalyzed CH activation of imines; the stoichiometric variant of the cyclomanganation was reported in 1971. The redox neutral reaction produces H2 as the major byproduct and eliminates the need for any oxidants, external ligands, or additives, thus standing out from known isoquinoline synthesis by transition-metal-catalyzed CH activation. Mechanistic studies revealed the five-membered manganacycle and manganese hydride species as key reaction intermediates in the catalytic cycle.

Taking tetraoxacalix[2]arene[2]triazine as a functionalization platform, a series of new amphiphilic molecules were synthesized in 18 to 53 % yields by using a fragment coupling protocol. These amphiphilic molecules self-assembled into stable vesicles in a mixture of THF and water, with the surface of the vesicles engineered by electron-deficient cavities. Various anions are able to selectively influence the size of self-assembled vesicles, following the order of F(-) < ClO4(-) < SCN(-) < BF4(-) < Br(-) < Cl(-) < NO3(-), as revealed by DLS measurements. Such a sequence was independent with the hydration cost and in agreement with the binding strength of anions with tetraoxacalix[2]arene[2]triazine host molecule, indicating that the anion-π interaction most probably competed over other possible weak interactions and accounted for this interesting selectivity. In addition, the chloride permeation process across the membrane of the vesicles was also preliminarily studied by means of fluorescent experiments. This study, in addition to providing the potentiality of heteracalixaromatics as new models to construct functional vesicles, opens a new avenue to study the anion-π interactions in aqueous and also potentially in living systems.

Rhodococcus sp. AJ270 is an efficient whole-cell system able to catalyze the stereoselective conversions of racemic α-substituted phenylacetonitriles and amides under very mild conditions into enantiopure carboxylic acids and derivatives. The nitrile hydratase involved generally has a broad substrate spectrum against phenylacetonitriles irrespective of the electronic nature of the α-substituent while the amidase is very sensitive to both the electronic and steric factors of the substituent of amides. The overall enantioselectivity of nitrile hydrolysis is mainly determined by the combination of selectivities of nitrile hydratase and of amidase, with the latter being a major contributor. The amidase has high S- enantiocontrol against amides while the nitrile hydratase exhibits low R -selectivity against nitriles. The scope and limitations of this enantioselective biotransformation process are discussed.

A discrete S6-symmetrical (H2O)32 cluster was encapsulated in the cavity of an organic co-crystalline supermolecule constructed by the co-crystallization of guanidinium and benzenetribenzoate ions through hydrogen bonds, pi-pi and cation-pi interactions.

N-Styryl-3-aryl-1-methylaziridine-2-carboxamides, which were readily obtained from the cross coupling reaction between 3-aryl-1-methylaziridine-2-carboxamides and 1-aryl-2-bromoethenes catalyzed by CuI/N,N-dimethylglycine in the presence of Cs(2)CO(3), underwent a base-mediated intramolecular nucleophilic aziridine ring opening reaction effectively via the carbon-carbon bond cleavage of aziridine to afford the ring expanded imidazolidin-4-one products in good yields.

The synthesis of chiral calix[4]arenes with tartaric acid ester moieties has been achieved by the reactions of tartaric ester chloroacetates with calix[4]arenes in moderate yields. All the chiral calix[4]arene derivatives are in a cone conformation according to the 1 H NMR doublet–doublet pattern of the protons of the methylene groups between the phenol rings. The results of NMR and specific rotations indicate that the molecules have C 2 symmetry with asymmetric features.

Effective nonenzymatic kinetic resolution of racemic m-nitro-substituted inherently chiral aminocalix[4]arenes with Boc-l-proline as the acylating reagent is described, which provides an efficient and convenient method for the enantioselective synthesis of meta-substituted aminocalix[4]arenes.

An approach for synthesis of 4-tert-butylcalix[4]arenes bearing two Schiff base units at the lower rim 4a-u in excellent yields is described. All 21 compounds 4a-u have been achieved by treatment of 1,3-distally substituent 4-tert-butylcalix[4]arene amine 3 with aromatic or heterocyclic aldehydes in ethanol.

The synthesis and reactions of glycopyranosyl heterocyclic ketene aminals were investigated. Under mild conditions, the benzoyl-substituted heterocyclic ketene aminals 3 or 4 underwent O-glycosylation with tetra- O -acetyl- α - d -glucopyranosyl bromide (1) using mercuric cyanide or silver trifluoromethanesulfonate as catalyst in acetonitrile to give O-glycopyranosyl heterocyclic ketene aminals 5–7 and 8–11 , respectively. The β-anomers were the sole products. By the O-glycosylation of heterocyclic ketene aminals with 1 , the O-attack of heterocyclic ketene aminals was carried out for the first time. Some of 5–11 in the synthesis of oligosaccharides 14 and 15 can provide a valuable leaving group at the anomeric position of the glycopyranosyl ring. Compounds 6c or 10c may be potentially useful as glycosyl donors in the synthesis of oligosaccharides.

The synthesis of 1-methyl-3-(arylthio)-1H-indoles has been achieved by the photoredox reaction of N-methylindoles with readily available arylsulfonyl chlorides in moderate yields.

A novel type of ditopic ion pair receptors based on anion–π interaction is reported. Oxacalix[2]arene[2]triazine azacrowns were synthesized efficiently from a one-pot reaction between 2,4-dichloro-4-methoxytriazine and 3,5-dihydroxybenzaldehyde followed by condensation with a diamine and reduction of bisimine; they acted as selective ditopic receptors to recognize ion pairs.

Catalyzed by FeCl3 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.

Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase and amidase containing microbial whole cell catalyst, a number of racemic 1-arylmethyl- and 1-allyl-4-oxoazetidine-2-carbonitriles and carboxamides underwent efficient transformations under very mild conditions to produce enantiopure functionalized S-amide and R-acid products in excellent yields. While the nitrile hydratase showed good enzyme activity but virtually no enantioselectivity, the amidase displayed high R-enantioselectivity against almost all amide substrates tested. The synthetic applications of the resulting functionalized chiral β-lactam derivatives were demonstrated by the facile preparation of β-lactam-fused heterocyclic compounds.

An organic crystal has been designed and constructed by the hydrogen-bond-directed self-assembly of TCA and dpyb, which possesses the large honeycomb net with 5.1 x 5.1 nm cavities and a novel interpenetrated n-Borromean linked topology.

Catalyzed by a chiral Cr(III)(salen)Cl complex 3e, tertiary enamides 1 underwent an efficient and enantioselective intramolecular addition reaction to an activated carbonyl moiety to produce in excellent yield highly enantioenriched 1H-pyrrol-2(3H)-one derivatives 2 that bear a hydroxylated quaternary carbon atom. The synthetic application of resulting compounds has been demonstrated in the synthesis of (3S,5S)-3,5-diphenyl-3-pyrrolidinol.

Heterocyclic ketene aminals 5 or 3H-1,5-benzodiazepines 4 were obtained from the reaction of benzoyl substituted ketene dithioacetals 1 with various diamines 2. The mechansim of formation of these two different products are discussed.

Catalyzed by a chiral Cr(III)(salen)Cl complex 3e, tertiary enamides 1 underwent an efficient and enantioselective intramolecular addition reaction to an activated carbonyl moiety to produce in excellent yield highly enantioenriched 1H-pyrrol-2(3H)-one derivatives 2 that bear a hydroxylated quaternary carbon atom. The synthetic application of resulting compounds has been demonstrated in the synthesis of (3S,5S)-3,5-diphenyl-3-pyrrolidinol.

Under very mild aerobic conditions, azacalix[1]arene[3]pyridine underwent highly efficient C-H activation with Cu(ClO(4))(2).6H(2)O to form a stable aryl-Cu(III) complex which reacted rapidly with various nucleophiles at ambient temperature to afford diverse functionalized azacalix[1]arene[3]pyridine derivatives in excellent yields.

In the presence of K(2)CO(3) in refluxing THF, dichloro-substituted tetraoxacalix[2]arene[2]triazine, a readily available macrocyclic compound from cyanuric acid chloride and benzyl 1,3-dihydroxybenzoate, underwent highly efficient nucleophilic displacement reactions with bis-nucleophilic reagents of different geometry, length and chirality in a 2+2 fashion to produce large and size-tunable cavity bis-tetraoxacalix[2]arene[2]triazines in good to excellent yields.

Catalyzed by Rhodococcus erythropolis AJ270 (whole cell catalyst) under very mild conditions, a number of racemic trans-3-arylaziridine-2-carbonitriles and amides were efficiently transformed into enantiopure 2R,3S-3-arylaziridine-2-carboxamides. While the nitrile hydratase exhibits low selectivity against nitrile substrates, the amidase is highly enantioselective toward 2S,3R-3-arylaziridine-2-carboxamides. Upon the treatment with catalytic hydrogenation, amine, or water in the presence of one equivalent of TFA, the resulting aziridine-2-carboxamides underwent highly efficient and stereospecific ring-opening reactions to produce enantiopure α-amino-, α,β-diamino-, and α-amino-β-hydroxy-propanamide derivatives in high yields.

A new fluorescent chemosensor based on calix[4]arene bearing four iminoquinoline subunits on the upper rim was conveniently synthesized, which showed a remarkable enhanced fluorescent intensity in the presence of Cu(2+) ion and a high selectivity toward Cu(2+) ion over a wide range of tested metal ions in acetonitrile.

Ketene S,S-acetals 2 react with 2-almino-1-ethanethiol to afford the substituted 2-methylenethiazolidines 3. The structure of these products as ketene N,S-acetals is confirmed by spectroscopic data. Compounds 3a-f react with esters of α,β-yunsaturated acids to give thiazolo[3,2-a]pyrid-5-one derivatives 4, 6, and 7 through an electrophilic addition and cyclocondensation sequences

Catalyzed by Rhodococcus erythropolis AJ270 (whole cell catalyst) under very mild conditions, a number of racemic trans-3-arylaziridine-2-carbonitriles and amides were efficiently transformed into enantiopure 2R,3S-3-arylaziridine-2-carboxamides. While the nitrile hydratase exhibits low selectivity against nitrile substrates, the amidase is highly enantioselective toward 2S,3R-3-arylaziridine-2-carboxamides. Upon the treatment with catalytic hydrogenation, amine, or water in the presence of one equivalent of TFA, the resulting aziridine-2-carboxamides underwent highly efficient and stereospecific ring-opening reactions to produce enantiopure alpha-amino-, alpha,beta-diamino-, and alpha-amino-beta-hydroxy-propanamide derivatives in high yields.