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Supramolecular carrier-mediated chemotherapy is a highly attractive strategy for targeted drug delivery. In this study, four novel biotin-linked calix[4]arenes BPCA1-BPCA4 have been rationally designed to construct nano-complex with doxorubicin. The in vitro and in vivo assessments reveal that BPCA4-DOX with excellent stability are capable of affording significantly superior anti-tumor activity and lower side effects. [ABSTRACT FROM AUTHOR]

DABCO promoted one‐pot three‐component reaction of aromatic amines, dialkyl but‐2‐ynedioates and MBH nitriles of isatins selectively afforded two diastereomeric spiro[indoline‐3,4′‐pyridines] in comparable yields. On the other hand, DABCO promoted cyclization of dialkyl but‐2‐ynedioates and MBH carbonates of isatins in DCM at room temperature gave spiro[cyclopentane‐1,3′‐indoline] derivatives, while the reaction of dialkyl but‐2‐ynedioates and MBH nitriles of isatins in chloroform at 70 °C resulted in unique cyclopenta[c]quinolone derivatives with ring‐opening of isatin moiety. A plausible reaction mechanism was rationally proposed to explain formation of the different products. [ABSTRACT FROM AUTHOR]

A convenient synthetic protocol for the construction of spiro[indoline‐3,3′‐quinoline]‐2,5′‐dione motifs was successfully developed by base promoted one‐pot three‐component reaction. In the presence of piperidine, three‐component reaction of ammonium acetate, aromatic aldehydes and the in situ generated 3‐isatyl 1,4‐dicarbonyl compounds, which were derived from base mediated addition of dimedone to 3‐methyleneoxindoles, resulted in two diastereoisomers of spiro[indoline‐3,3′‐quinoline]‐2,5′‐dione derivatives in good yields and with good diastereoselectivity. The stereochemistry of the reaction was clearly elucidated by isolation of two diastereomers and determination of several single crystal structures. [ABSTRACT FROM AUTHOR]

The palladium‐catalyzed asymmetric carboamination reaction is one of the most significant transformations in organic chemistry. Herein, we report the first palladium‐catalyzed asymmetric alleneamination of β,γ‐unsaturated hydrazones with propargylic acetates. This protocol enables the efficient installation of various multisubstituted allene groups onto dihydropyrazoles in good yields with excellent enantioselectivities. The chiral sulfinamide phosphine ligand Xu‐5 exhibits highly efficient stereoselective control in this protocol. The salient features of this reaction include the readily available starting materials, a broad substrate scope, an easy scale‐up, mild reaction conditions and versatile transformations. [ABSTRACT FROM AUTHOR]

The palladium‐catalyzed asymmetric carboamination reaction is one of the most significant transformations in organic chemistry. Herein, we report the first palladium‐catalyzed asymmetric alleneamination of β,γ‐unsaturated hydrazones with propargylic acetates. This protocol enables the efficient installation of various multisubstituted allene groups onto dihydropyrazoles in good yields with excellent enantioselectivities. The chiral sulfinamide phosphine ligand Xu‐5 exhibits highly efficient stereoselective control in this protocol. The salient features of this reaction include the readily available starting materials, a broad substrate scope, an easy scale‐up, mild reaction conditions and versatile transformations. [ABSTRACT FROM AUTHOR]

p-TsOH promoted annulation reaction of 3-(indol-3-yl)maleimides and (indol-2-yl)diphenylmethanols in chloroform afforded functionalized pyrrolo[3′,4′:6,7]cyclohepta[1,2-b:4,5-b′]diindoles in satisfactory yields, in which a formal [4+3] cycloaddition and an unprecedented rearrangement of the maleimide motif from the C3- to C2-position of the indole ring was firstly observed. Alternatively, the similar reaction of 3-(indol-3-yl)maleimides and 3-hydroxy-3-(indol-3-yl)-indolin-2-ones in acetonitrile gave functionalized spiro[indoline-3,9′-pyrrolo[3′,4′:4,5]cyclopenta[1,2-b]indole] in good yields and with high diastereoselectivity. On the other hand, p-TsOH promoted reaction of 3-(indol-3-yl)maleimides and 2-hydroxy-2-(indol-3-yl)-indene-1,3-diones gave functionalized spiro[indene-2,9′-pyrrolo[3′,4′:4,5]cyclopenta[1,2-b]indoles] as major products and spiro[indene-2,9′-pyrrolo[3′,4′:6,7]cyclohepta[1,2-b:4,5-b′]diindoles] as minor products. [ABSTRACT FROM AUTHOR]

A series of mono-functionalized pillar[5]arene Schiff bases were successfully synthesized by amidation reaction of pillar[5]arene mono-O-butyrate with various diaminoalkanes and sequential condensation reaction of monoaminoalkyl-functionalized pillar[5]arenes with substituted salicylaldehydes. 1H NMR and 2D NOESY spectra clearly showed that all monoaminoalkyl-functionalized pillar[5]arenes could form pseudo[1]rotaxanes by self-sorting of aminoalkyl chain into the cavity of pillar[5]arene, while pillars[5]arene Schiff bases with longer than butylene chain (n ≥ 4) could form stable [1]rotaxane. The fluorescence spectrophotometry indicated that pillar[5]arene Schiff bases coordinated with Zn2+ ion to form interesting complexes with 2:1 coordination ratio and with significant enhance of the fluorescence intensity. [ABSTRACT FROM AUTHOR]

Theranostics play an important role in cancer treatment due to its realized real-time tracking of therapeutic efficacy in situ. In this work, we have designed and synthesized a terpyridine-modified pillar [5]arenes (TP5). By the coordination of terpyridine and Zn2+, the complex TP5/Zn was obtained. Then, supramolecular amphiphile can be constructed by using host–guest complexation between a polyethylene glycol contained guest (PM) and TP5/Zn. Combining the fluorescence properties from the terpyridine group and the amphiphilicity from the system, the obtained TP5/Zn/PM can further be self-assembled into fluorescent particles with diameters of about 150 nm in water. The obtained particles can effectively load anti-cancer drugs and realize living cell imaging and a precise release of the drugs. [ABSTRACT FROM AUTHOR]

Triethylamine promoted cycloaddition reaction of phenacylmalononitriles and o-hydroxychalcones in ethanol at room temperature gave multifunctionalized cyclopent-3-ene-1-carboxamides in good yields and with high diastereoselectivity. More importantly, the similar reaction of phenacylmalononitriles and chalcone o-enolates in ethanol at room temperature afforded functionalized 2-oxabicyclo[2.2.1]heptane derivatives in satisfactory yields and with high diastereoselectivity. A rational domino reaction was tentatively proposed to explain the selective formation of different cyclic compounds and the diastereoselectivity of the reaction. [ABSTRACT FROM AUTHOR]

Two pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper were synthesized and characterized fully, and could be further applied in the fluorescence turn-on sensing of Zn2+ in water. [ABSTRACT FROM AUTHOR]

Triethylamine promoted one-pot three-component reaction of alkyl glycinate hydrochloride, dialkyl but-2-ynedioate and 2-(2-hydroxybenzylidene)-1,3-indanediones in ethanol at room temperature efficiently resulted in unique 8a 14-(epoxymethano)indeno[1′,2′:2,3]chromeno[4,3-a]pyrrolizines in satisfactory yields. On the other hand, the base promoted four-component reaction of dialkyl but-2-ynedioate, salicylaldehydes, 1,3-indanediones and secondary α-amino acids such as proline, thiazolidine-4-carboxylic acid and sarcosine in refluxing ethanol gave complex N,O,S-containing polyheterocyclic compounds in good yields. The reaction mechanism included a cascade reaction process of the in situ generation of a special kind of azomethine ylide, 1,3-dipolar cycloaddition and annulation of phenoxide. [ABSTRACT FROM AUTHOR]

The one‐pot three‐component reaction of L‐proline, isatins and 1‐(2‐hydroxyphenyl)‐3‐phenylprop‐2‐en‐1‐ones and sequential reaction with methyl propiolate in refluxing methanol resulted in novel functionalized spiro[chromane‐2,3′‐indoline]‐2′,4‐diones as major products and spiro[chromeno[3,2‐d]azocine‐2,3′‐indolin]‐3‐ yl)acrylate as minor products. On the other hand, the similar one‐pot‐three‐component reaction of L‐proline, isatins and 3‐(2‐hydroxyphenyl)‐1‐phenylprop‐2‐en‐1‐ones and sequential reaction with methyl propiolate in refluxing acetonitrile predominately afforded the unique 6b,14‐(epoxy[1,2]benzeno)pyrrolo[1′,2′:1,2]azocino[4,5‐c]quinoline‐8‐carboxylates in satisfactory yields. [ABSTRACT FROM AUTHOR]

A series of azobenzene-bridged dipillar[5]arenes were conveniently synthesized by coupling reaction of aminoalkyl-functionalized pillar[5]arenes with azobenzene-4,4'-dioxyacetic acid or azobenzene-4,4'-dioxybutanoic acid in dry chloroform under the combinatorial catalysis of HOBt/EDCl. 1H NMR, 2D NOESY spectra and single crystal structure clearly indicated that the unique bis-[1]rotaxanes could be formed by threading two diaminoalkylene units into the two cavities of pillar[5]arenes depending on the length of the diaminoalkylene chains. Under light irradiation at 365 nm, the trans-azobenzene unit transferred to cis-configuration, while the basic bis-[1]rotaxane structure was kept unchanged. [ABSTRACT FROM AUTHOR]

The condensation reaction of mono-amido-functionalized pillar[5]arenes with tere- and iso-phthaloyl diisothiocyanates in acetone under ultrasonic irradiation afforded tere- and iso-phthaloylthiourea-bridged dipillar[5]arenes. The similar reaction of mono-amido-functionalized pillar[5]arenes with 1,ω-bis(4-isothiocyanatophenoxy)alkanes also afforded diphenoxyalkylene thiourea-bridged dipillar[5]arenes. 1H NMR and NOESY spectra clearly indicated that bis-[1]rotaxanes were formed by insertion of longer alkylene chains into the cavities of two pillar[5]arenes. On the other hand, the free-forms of dipillar[5]arenes were obtained with the shorter ethylene chains existing on the outside of the cavities of two pillar[5]arenes. [ABSTRACT FROM AUTHOR]

A very simple and highly efficient protocol for synthesizing tetra- and penta-substituted benzene derivatives has been developed. This synthesis was achieved by carrying out a tetramethylguanidine (TMD)-promoted reaction of 4-(N,N-dimethylamino)-1-phenacyl-pyridinium bromide with chalcone o-enolates in DMF at 100 °C. The reaction mechanism was believed to involve a sequential annulation reaction of pyridinium ylide, ring-opening of the initially formed pyran ring and aromatization process. [ABSTRACT FROM AUTHOR]

A series of the functionalised pillar[5]arene ureidopyrimidinone derivatives were successfully synthesised by the condensation reaction of mono-amido-functionalised pillar[5]arenes with 2-(1-Imidazolylcarbonylamino)-6-methyl-4-pyrimidinone in dry chloroform. 1H NMR, 2D NOESY spectra and single crystal structure clearly indicated that novel [1]rotaxanes were formed by insertion of longer alkylene chain into the cavities of the pillar[5]arenes. On the other hand, the ureidopyrimidinone-functionalised pillar[5]arenes tend to form the dimer in chloroform and in solid state through the self-complementary quadruple hydrogen bonding of the ureidopyrimidinone. [ABSTRACT FROM AUTHOR]

The three‐component reaction of isoquinoline, dialkyl but‐2‐ynedioate and 4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐ones in acetonitrile at room temperature gave functionalized spiro[pyrazole‐4,1′‐pyrido[2,1‐a]isoquinolines] in satisfactory yields with cis/cis‐diastereoisomer as major product. On the other hand, the similar three‐component reaction with quinoline afforded both cis/cis‐ and cis/trans‐isomeric spiro[pyrazole‐4,4′‐pyrido[1,2‐a]quinolines] in nearly comparable yields. The reaction was finished with in situ generation of Huisgen' 1,4‐dipole, sequential Michael addition and annulation reaction process. [ABSTRACT FROM AUTHOR]

The concentrated hydrochloride catalyzed reaction of 3‐(indol‐3‐yl)maleimides with (E)‐4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐ones in acetonitrile at room temperature afforded unexpected Michael addition product in high yields, which could be easily converted to the cis/trans‐diastereoisomers of spiro[pyrazole‐4,5′‐pyrrolo[3,4‐c]carbazoles] with the nearly 2 : 1 ratios by further oxidation with DDQ. On the other hand, the similar one‐pot two‐step reaction of 3‐(indol‐3‐yl)maleimides with (E)‐5‐arylidene‐2‐phenylthiazol‐4‐one predominately gave cis‐diastereoisomers of spiro[pyrrolo[3,4‐c]carbazole‐5,5′‐thiazoles] in satisfactory yields. The reaction mechanism included domino acid catalyzed Michael addition and DDQ oxidative coupling process [ABSTRACT FROM AUTHOR]

The DABCO promoted domino reaction of 1‐(2‐hydroxyphenyl)‐3‐phenylprop‐2‐en‐1‐ones and alkyl propiolate or dialkyl but‐2‐ynedioate in toluene at high temperature resulted in methyl 3‐(2‐hydroxybenzoyl)‐1‐naphthoates or dimethyl 3‐(2‐hydroxybenzoyl)naphthalene‐1,2‐dicarboxylate in moderate to good yields. The hydroxyl group played a crucial rule in the reaction. The reaction mechanism of this formal [4+2] cycloaddition reaction was believed with initially formation of methyl 3‐(2‐cinnamoylphenoxy)acrylate, intramolecular Diels‐Alder reaction, ring‐opening of benzo[b]xanthene and aromatization process. [ABSTRACT FROM AUTHOR]

DDQ promoted the reaction of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones with 3-methyleneoxindoles in refluxing ethanol resulting in functionalized dihydrospiro[carbazole-1,3′-indolines] in good yields and with high diastereoselectivity. Similar reactions with 5-arylidene-1,3-dimethylbarbituric acids also afforded functionalized spiro[carbazole-1,5′-pyrimidines] in satisfactory yields. The reaction actually proceeded via the DDQ oxidative dehydrogenation of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones to the corresponding 3-vinylindoles, their sequential Diels–Alder reaction with dienophiles and further isomerization process. DFT calculations showed that the Diels–Alder reaction has a normal electron-demanding character. [ABSTRACT FROM AUTHOR]

Series of novel p-tert-butyldihomooxacalix[4]arene mono-Schiff bases including dithiocarbonylhydrazones and dicarbonohydrazones were conveniently synthesized by condensation reaction of p-tert-butyldihomooxacalix[4]arene O-alkoxy-substituted benzaldehydes with benzyl hydrazinecarbodithioate and N'-(2-hydroxybenzylidene)hydrazinecarbohydrazide. More importantly, the similar condensation of p-tert-butyldihomooxacalix[4]arene mono-substituted benzaldehydes with various N,N′-alkylenebis(hydrazinecarbothioamides) afforded interesting dithiosemicarbazone-bridged bis(p-tert-butyldihomooxacalix[4]arenes). [ABSTRACT FROM AUTHOR]

The acetic acid promoted reaction of 3-hydroxy-3-(indol-3-yl)indolin-2-ones and mercapto-substituted β-enamino esters showed very interesting molecular diversity. The reaction in ethanol at room temperature in the presence of acetic acid resulted in two diastereoisomeric 3,3-disubstituted oxindoles in high yields. When the reaction was carried out in refluxing ethanol, the reaction with 3-hydroxy-3-(indol-3-yl)indolin-2-ones with N-alkyl groups gave polycyclic spirooxindoles in satisfactory yields. However, a similar reaction with 3-hydroxy-3-(indol-3-yl)indolin-2-ones with NH groups afforded functionalized dihydroindolo[3,2-c]phenothiazines with sequential ring-opening of oxindole. A plausible domino annulation mechanism was rationally proposed for the formation of different kinds of polycyclic compounds. [ABSTRACT FROM AUTHOR]

TEMPO promoted cycloaddition reaction of different kinds of ketohydrazones or aldohydrazones with 3-phenacylideneoxindoles showed very interesting molecular diversity according to the chemical structures and reaction conditions. The reactions with 1-(3,4-dihydronaphthalen-1-ylidene)-2-arylhydrazines or 1-cyclohexylidene-2-arylhydrazines in acetonitrile at 80 °C afforded functionalized spiro[benzo[h]cinnoline-3,3′-indolines] or spiro[cinnoline-3,3′-indolines] via aza-Diels–Alder reaction of the in situ generated 1,2-diaza-1,3-diene. The reactions with 2-(2-phenylethylidene)-1-arylhydrazines in dioxane afforded functionalized spiro[indoline-3,3′-pyrazoles] though a [3+2] cycloaddition reaction of the in situ generated 1,3-dipolar azomethine imine. On the other hand, a similar reaction in acetonitrile unusually resulted in pyrazole derivatives via sequential [3+2] cycloaddition and a ring-opening process. [ABSTRACT FROM AUTHOR]

The acetic acid catalyzed three‐component reaction of pyrrolidine, aromatic aldehydes and 4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐one in refluxing toluene gave functionalized 7′‐(E)‐benzylidenespiro[pyrazole‐4,1′‐pyrrolizines] in good yields and with high diastereoselectivity. The similar reaction with 2‐arylidene‐N,N'‐dimethylbarbiturates resulted in mixture of Z/E‐isomers of 7′‐ arylidenespiro[pyrimidine‐5,1′‐pyrrolizines] in good yields. However, the three‐component with N‐phenylmaleimides and sequential oxidation with DDQ reaction gave 8‐(E)‐arylidenedihydropyrrolo[3,4‐a]pyrrolizines in satisfactory yields. The reaction mechanism included sequential β‐C−H functionalization of pyrrolidine, generation of conjugated azomethine ylides, and sequential [3+2] cycloaddition with active alkenes. [ABSTRACT FROM AUTHOR]

Spiro[indoline‐3,7′‐pyrrolo[1,2‐a]azepines] were conveniently synthesized in satisfactory yields and with high diastereoselectivity from three‐component reaction of L‐proline, isatins and chalcones and sequential reaction with dimethyl but‐2‐ynedioate or methyl propiolate in refluxing methanol. The ferrocenyl‐chalcones and dibenzylideneacetones were also successfully used in this one‐pot two‐step reaction to give novel ferrocenyl and styryl‐substituted spiro compounds. The reaction mechanism included domino [3+2] cycloadddtition reaction of azomethine ylide with chalcone and ring‐expansion reaction of in situ generated spiro[indoline‐3,3′‐pyrrolizine] with electron‐deficient alkynes. [ABSTRACT FROM AUTHOR]

A series of novel functionalized p-tert-butyldihomooxacalix[4]arene mono-Schiff bases were conveniently synthesized by two-step reaction process. The synthetic rout included alkylation of p-tert-butyldihomooxacalix[4]arene with O-chloroalkoxy-substituted benzaldehydes and sequential condensation with 2-hydroxybenzohydrazide, 2-picolinohydrazideand aminothiourea. The single crystal structures of two p-tert-butyldihomooxacalix[4]arenederivatives were determined by X-ray single crystal diffraction method. The coordination abilities of dihomooxacalix[4]arene mono-Schiff bases towards transition metal ions were preliminarily investigated by UV-Vis spectra. [ABSTRACT FROM AUTHOR]

An efficient and convenient synthetic protocol for functionalized chromeno[3,4-b]pyrroles was successfully developed through a K3PO4 promoted three-component reaction of pivaloylacetonitrile (benzoylacetonitrile), dialkyl but-2-ynedioates and 2-aryl-3-nitrochromenes in refluxing ethyl acetate. A similar three-component reaction of malononitrile, dialkyl but-2-ynedioates and 2-aryl-3-nitrochromenes resulted in polysubstituted benzo[c]chromene derivatives in good yields. Plausible reaction mechanisms for selective formation of two annulated chromanes were rationally proposed. [ABSTRACT FROM AUTHOR]

The triethylamine promoted dimerization of N‐phenacylbenzothiazolium bromides in ethanol resulted in a mixture of N,O,S‐containing six fused‐cyclic compounds and N,S‐containing five fused‐cyclic compounds in moderate yields. On the other hand, the base promoted dimerization of N‐benzylbenzothiazolium bromides selectively afforded 2,3‐bis(4‐methylbenzyl)‐2,3‐dihydro‐2,2′‐bibenzo[d]thiazoles or 3,3′‐bis(4‐methoxybenzyl)‐2,2′‐spirobi[benzo[d]thiazoles] depending on the electronic effect of the substituents on the benzyl group. The plausible formation mechanisms of the various annulation products were rationally proposed. [ABSTRACT FROM AUTHOR]

The base catalyzed aldol condensation of various N‐benzylisatins with 1‐acetyl‐N‐arylcyclopropanecarboxamides resulted in functionalized 3‐hydroxyoxindolin‐2‐ones in high yields, which were in turn successfully transferred to functionalized 6‐(2‐oxoindolin‐3‐yl)‐5‐azaspiro[2.4]heptanes in acetic acid in the presence of the concentrated hydrochloric acid by sequential acid catalyzed dehydration and aza‐Michael addition process. The 1H NMR spectra and the single crystal structure indicated that the obtained functionalized 6‐(2‐oxoindolin‐3‐yl)‐5‐azaspiro[2.4]heptanes have a S,S‐configuration. [ABSTRACT FROM AUTHOR]

A highly regioselective Cu-catalyzed difunctionalization of different N-heteroarene salts such as quinolinium and benzothiazolim salts was developed with ether and X− (X = Br, Cl) as the halogen source under mild conditions. This transformation involved the combination of oxidative coupling, selective free radical resonance and a copper-catalyzed halogen atom-transfer radical process. The regiochemistry was further verified by DFT calculations. This method not only provided an efficient way to prepare various substituted azaarenes but also achieved the selective construction of C(sp2)–X (X = Br, Cl) bonds from a halogen anion and nucleophilic carbon atom via a free-radical process. [ABSTRACT FROM AUTHOR]

NH4I promoted three‐component reaction of indoles, cyclic ketones and maleimides in toluene at 140 °C afforded polysubstituted cyclic fused pyrrolo[3,4‐a]carbazoles in good yields. The reaction mechanism included sequential Lewis acid catalyzed 3‐alkenylation of indole, Diels‐Alder reaction and aromatization process. More importantly, the similar NH4I promoted reaction of indoles and acetophenones with two molecules of maleimides in refluxing toluene resulted in the complex tetrahydro‐4,10a‐[3,4]epipyrrolopyrrolo[3,4‐a]carbazoles in satisfactory yields via double Diels‐Alder reaction. On the other hand, tetrahydropyrrolo[3,4‐a]carbazoles can be easily prepared in high yields by conc. HCl catalyzed three‐component reaction of indole and acetophenone and one molecules of maleimide in refluxing ethanol. [ABSTRACT FROM AUTHOR]

NH4I promoted three‐component reaction of indole, acetophenones and 2‐arylidene‐1,3‐indanediones in toluene at 120 °C afforded cis‐2,4‐diaryl‐substituted dihydrospiro[carbazole‐1,2′‐indene]‐1′,3′‐diones in good yields. Under same reaction conditions, NH4I promoted three‐component reaction of indole, acetophenones and (2‐oxoindolin‐3‐ylidene)malononitriles gave dihydrospiro[carbazole‐1,3′‐indolines] in moderate to good yields and with high diastereoselectivity. The reaction mechanism included sequential generation of 3‐alkenylindole, Diels‐Alder reaction and aromatization process. [ABSTRACT FROM AUTHOR]

A TEMPO promoted oxidative aza‐Diels‐Alder reaction of ketohydrazones with 3‐methyleneoxindoles or 2‐arylidene‐1,3‐indanediones were successfully developed, This reaction provided an efficient synthetic protocol for novel functionalized spiro[indoline‐3,3′‐pyridazines] and spiro[indene‐2,3′‐pyridazines]. This reaction showed high diastereoselectivity and strict substituent's electron effect, which might be due to the reaction mechanisms process including sequential oxidative generation of 1,2‐diaza‐1,3‐dien and normal electron‐demand aza‐Diels‐Alder reaction. [ABSTRACT FROM AUTHOR]

A new type of azomethine ylides, which was in situ generated by the reaction of ethyl glycinate hydrochloride and dimethyl acetylenedicarboxylate, reacted with 3-phenacylideneoxindoline-2-ones in ethanol to give polysubstituted spiro[indoline-3,3′-pyrrolidines] in good yields. The biological activities of the various spiro[indoline-3,3′-pyrrolidines] obtained were investigated by in vitro evaluation against mouse breast cancer cells 4T1, mouse colon cancer cells CT26, human liver cancer cells HepG2 and human lung cancer cells A549 by MTT assay. The results demonstrated that eight compounds showed cytotoxicity towards HepG2 cells, and compound 2j showed promising cytotoxicity towards CT26 cells with an IC50 value of about 50 μg mL−1 in 24 h. [ABSTRACT FROM AUTHOR]

A series of p-tert-butyldihomooxacalix[4]arenes bearing phenolic hydroxyls and thiourea moieties were prepared to investigate their anion binding behavior. These compounds showed F− binding according to 1H NMR titration experiments. Among them, dihomooxacalix[4]arenes bearing phenyl and benzyl thiourea (2a and 2b) showed multiple interactions with added F−, including N–H…F, O–H…F hydrogen bonds and “through-space” C–H…F− interactions between F− and the attached aromatic segment of thiourea. A conformational change of the dihomooxacalix[4]arene cavity was observed as well and proved by theoretical calculations. The dihomooxacalix[4]arene bearing methyl thiourea (2c) also showed the formation of N–H…F, O–H…F hydrogen bonds, but less conformational change of the dihomooxacalix[4]arene cavity according to 1H NMR titration results. The bis-dihomooxacalix[4]arene (3) showed clear N–H…F hydrogen bond formation upon addition of F− as characterized by 1H NMR spectroscopy. [ABSTRACT FROM AUTHOR]

The piperidine promoted three‐component reaction of N‐alkylpiperidin‐4‐ones, malononitrile and 2‐arylidene‐1,3‐indanediones in ethanol selectively resulted in the spiro[indene‐2,7′‐isoquinoline] and the ring‐opened cis‐ or trans‐1,2,8,8a‐tetrahydroisoquinoline derivatives at room temperature or at the elevated temperature. However, the four‐component reaction N‐alkylpiperidin‐4‐ones, malononitrile, aromatic aldehydes and 1,3‐indanedione in refluxing ethanol mainly afforded ring‐opened cis‐1,2,8,8a‐tetrahydroisoquinoline derivatives in good yields and with high diastereoselectivity. A plausible domino reaction mechanism was proposed for the formation of the different polycyclic products. The piperidine promoted three‐component reaction of N‐alkylpiperidin‐4‐ones, malononitrile and 2‐arylidene‐1,3‐indanediones in ethanol selectively resulted in the spiro[indene‐2,7′‐isoquinoline] and the ring‐opened cis‐ or trans‐1,2,8,8a‐tetrahydroisoquinoline derivatives at room temperature or at the elevated temperature. However, the four‐component reaction N‐alkylpiperidin‐4‐ones, malononitrile, aromatic aldehydes and 1,3‐indanedione in refluxing ethanol mainly afforded ring‐opened cis‐1,2,8,8a‐tetrahydroisoquinoline derivatives in good yields and with high diastereoselectivity. [ABSTRACT FROM AUTHOR]

Abstract: The acid-promoted three-component reaction of o-aminophenol or 2-aminoethanol with dialkyl acetylenedicarboxylate and 3-phenacylideneoxindolines in refluxing acetonitrile afforded functionalized oxindolinyl-substituted benzo[b]pyrrolo[1,2-d][1,4]oxazine or pyrrolo-[2,1-c][1,4]oxazine derivatives in good yields. However, using o-phenylenediamine only resulted in oxindolinyl-substituted 3,4-dihydroquinoxaline derivatives.Graphical abstract: [ABSTRACT FROM AUTHOR]

The three‐component reaction of quinoline, dimethyl acetylenedicarboxylate and 2‐arylidene‐1,3‐indanediones or 5‐arylidene‐N,N'‐dimethylbarbituric acids in acetonitrile at room temperature afforded polysubstituted spiro[indene‐2,4′‐pyrido[1,2‐a]quinolines] or spiro[pyrido[1,2‐a]quinoline‐4,5′‐pyrimidines] in high yields and with high diastereoselectivity. However, the similar reaction of dimethyl acetylenedicarboxylate with 2‐arylidene‐1,3‐indanediones in the presence of 4‐Dimethylaminopyridine (DMAP) gave unexpected dihydroindeno[1,2‐b]pyrene derivatives in satisfactory yields. This three‐component reaction containing quinoline might be the most sustainable reaction without release any waste. The three‐component reaction of quinoline, dimethyl acetylenedicarboxylate and 2‐arylidene‐1,3‐indanediones or 5‐arylidene‐N,N'‐dimethylbarbituric acids in acetonitrile afforded spiro[indene‐2,4′‐pyrido[1,2‐a]quinolines] or spiro[pyrido[1,2‐a]quinoline‐4,5′‐pyrimidines] in high yields and with high diastereoselectivity. The similar reaction with DMAP gave dihydroindeno[1,2‐b]pyrenes in satisfactory yields. [ABSTRACT FROM AUTHOR]

A library of novel spirooxindole-pyrrolidine derivatives were facilely synthesized via 1,3-dipolar cycloaddition of azomethine ylide generated from sarcosine and paraformaldehyde with various 3-methyleneoxindolines. The relative configuration of obtained spiro[indoline-3,3′-pyrrolidines] was successfully elucidated by determination of nine single-crystal structures. The antimicrobial activities and the inhibitory activity towards acetylcholinesterase of the synthesized spiro compounds were also preliminarily evaluated, in which the spiro[indoline-3,3′-pyrrolidine] 4d exhibited the most potent activity with an IC50 value of 69.07 ± 10.99 μM against acetylcholinesterase (AChE). [ABSTRACT FROM AUTHOR]