Switchable Regioselective Hydroalkylation of 2-Arylindoles with Maleimides

2021 ◽  
Author(s):  
Dhananjay S Nipate ◽  
Vikki N Shinde ◽  
R. Krishnan ◽  
Anil Kumar
Keyword(s):  
Ortho Position ◽  
Aryl Ring

A condition-based switchable regioselective hydroalkylation of 2-arylindoles with maleimides has been developed. The reaction in the presence of Ru(II)-catalyst provided hydroalkylation at ortho-position of C2-aryl ring via C-H activation whereas...

Evaluation of Pyrano[3,2 C] Quinoline Analogues as Anticancer Agents

2019 ◽  
Vol 19 (10) ◽  
pp. 1285-1292 ◽  
Author(s):  
Kuldip D. Upadhyay ◽  
Anamik K. Shah
Keyword(s):  
Anticancer Agents ◽  
Human Cancer ◽  
Biological Activities ◽  
Cytotoxic Agents ◽  
Tumor Growth Inhibition ◽  
Mice Model ◽  
One Pot ◽  
Aryl Ring ◽  
Hct 116

Background: Quinoline analogues exhibited diversified biological activities depending on the structure type. A number of natural products with pyrano[3,2-c]quinolone structural motifs and patented chromenes were reported as promising cytotoxic agents. Objective: The present study is aimed to evaluate a new series of pyrano[3,2-c]quinoline scaffolds derived from the fusion of bioactive quinolone pharmacophore with structurally diverse aryl substituted chromene for its cytotoxicity. Methods: A library of pyrano[3,2-c]quinoline analogues was prepared from one-pot multi component synthesis using various aromatic aldehydes, malononitrile and 2,4-dihydroxy-1-methylquinoline. The new synthetics were primarily screened for its cytotoxicity (IC50) against different human cancer cell lines in vitro. The promising synthetics were further evaluated in vitro for their potency against different kinase activity. The promising compounds were finally tested for their in vivo efficacy in SCID type mice HCT-116 tumor model. Results: The screening results revealed that compounds 4c, 4f, 4i and 4j showed promising activity in in vitro study. However, compound 4c was found to be the most potent candidate with 23% tumor growth inhibition in HCT-116 tumor mice model. Conclusion: The structure activity relationship suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2 c]quinolone moiety seems to have an important position for cytotoxicity activity. However, 3- chloro substitution at C4 aryl ring showed a significant alteration of the bioactive conformer of the parent scaffold and outcome with compound 4c as the most potent candidate of the series.

Novel meta-Benzothiazole and Benzimidazole Functionalised POCOP-Ni(II) Pincer Complexes as Efficient Catalysts in the Production of Diarylketones.

2021 ◽  
Author(s):  
Antonio Aldair Castillo-García ◽  
González-Sebastián Lucero ◽  
Leticia Lomas-Romero ◽  
Simon Hernandez-Ortega ◽  
Ruben Alfredo Toscano ◽  
...  
Keyword(s):  
Pincer Complexes ◽  
Aryl Ring

The synthesis of four novel non-symmetric Ni(II)-POCOP pincer complexes meta-functionalized with either benzothiazole or benzimidazole at the central aryl ring is described. All complexes were fully characterised in solution by...

scholarly journals Fluorescent Orthopalladated Complexes of 4-Aryliden-5(4H)-Oxazolones from the Kaede Protein: Synthesis and Characterization

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1238
Author(s):  
Eduardo Laga ◽  
David Dalmau ◽  
Sofía Arregui ◽  
Olga Crespo ◽  
Ana I. Jimenez ◽  
...  
Keyword(s):  
Intramolecular Interactions ◽  
Ortho Position ◽  
Fluorescent Properties ◽  
Ancillary Ligands ◽  
X Ray ◽  
Mononuclear Complexes ◽  
Fluorescence Measurements ◽  
Anionic Ligands ◽  
Order Of Magnitude

The goal of the work reported here was to amplify the fluorescent properties of 4-aryliden-5(4H)-oxazolones by suppression of the hula-twist non-radiative deactivation pathway. This aim was achieved by simultaneous bonding of a Pd center to the N atom of the heterocycle and the ortho carbon of the arylidene ring. Two different 4-((Z)-arylidene)-2-((E)-styryl)-5(4H)-oxazolones, the structures of which are closely related to the chromophore of the Kaede protein and substituted at the 2- and 4-positions of the arylidene ring (1a OMe; 1b F), were used as starting materials. Oxazolones 1a and 1b were reacted with Pd(OAc)2 to give the corresponding dinuclear orthometalated palladium derivates 2a and 2b by regioselective C–H activation of the ortho-position of the arylidene ring. Reaction of 2a (2b) with LiCl promoted the metathesis of the bridging carboxylate by chloride ligands to afford dinuclear 3a (3b). Mononuclear complexes containing the orthopalladated oxazolone and a variety of ancillary ligands (acetylacetonate (4a, 4b), hydroxyquinolinate (5a), aminoquinoline (6a), bipyridine (7a), phenanthroline (8a)) were prepared from 3a or 3b through metathesis of anionic ligands or substitution of neutral weakly bonded ligands. All species were fully characterized and the X-ray determination of the molecular structure of 7a was carried out. This structure has strongly distorted ligands due to intramolecular interactions. Fluorescence measurements showed an increase in the quantum yield (QY) by up to one order of magnitude on comparing the free oxazolone (QY < 1%) with the palladated oxazolone (QY = 12% for 6a). This fact shows that the coordination of the oxazolone to the palladium efficiently suppresses the hula-twist deactivation pathway.

scholarly journals Selective activation of C H bond of phenol in ortho-position into C OH bond in a two-phase system

2021 ◽  
Vol 150 ◽  
pp. 106277
Author(s):  
Ke Zheng ◽  
Song Shi ◽  
Hongchuan Xin ◽  
Jin Gao ◽  
Zengjian An
Keyword(s):  
Phase System ◽  
Ortho Position ◽  
Selective Activation ◽  
Two Phase

scholarly journals Iodobenzene-Promoted Pd-Catalysed ortho-Directed C–H Activation: The Synthesis of Benzothiazoles via Intramolecular Coupling

SynOpen ◽  
2017 ◽  
Vol 01 (01) ◽  
pp. 0001-0007 ◽  
Author(s):  
Meng-Tian Zeng ◽  
Wan Xu ◽  
Min Liu ◽  
Xing Liu ◽  
Cai-Zhu Chang ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Bond Formation ◽  
Formation Reaction ◽  
Aryl Ring ◽  
Thiourea Group

A series of 2-aminobenzothiazoles were synthesized by a palladium-catalysed oxidative coupling with good yields (62–89%). Iodobenzene was found to be effective as an additive in this intramolecular C–S bond-formation reaction. The directing thiourea group attached to the aryl ring is essential for the activation of the ortho C–H bond.

Formation of an air-stable diborane via a stepwise BH3 addition of pyrido[1,2-a]isoindole with H2 evolution

2021 ◽  
Vol 57 (77) ◽  
pp. 9882-9885
Author(s):  
Jiaqi Dong ◽  
Lutao Zhang ◽  
Dehui Tan ◽  
Jianfeng Wu ◽  
Nan Wang ◽  
...  
Keyword(s):  
H2 Evolution ◽  
Aryl Ring

A novel and air-stable organo(hydro)diborane featuring a five-membered aryl ring supported bridging B–C–B three-centre–two-electron (3c–2e) bond has been reported.

Vicarious nucleophilic amination of nitroquinolines with 4-amino-1,2,4-triazole

2008 ◽  
Vol 86 (7) ◽  
pp. 682-685 ◽  
Author(s):  
Barbara Szpakiewicz ◽  
Maria Grzegożek
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Substitution ◽  
Nitro Group ◽  
Para Position ◽  
Basic Medium ◽  
Ortho Position ◽  
Vicarious Nucleophilic Substitution

3-, 5-, 6-, 7- and 8-Nitroquinolines react with 4-amino-1,2,4-triazole in basic medium (potassium tert-butoxide-dimethyl sulfoxide) giving amino products of the vicarious nucleophilic substitution (VNS) of hydrogen, predominantly at ortho position to the nitro group, except 8-nitroquinoline, which reacts at para position. Additionally, furazano[3,4-f]- and furazano[3,4-h]quinoline were obtained in the case of 5- and 8- nitroquinoline, respectively. 2-Nitroquinoline was aminated to 2-quinolino(1,2,4-triazol-4-yl)amine in these conditions.Key words: nitroquinolines, vicarious nucleophilic substitution (VNS), 4-amino-1,2,4-triazole.

Conformational preferences in 2-nitrophenylthiolates: interplay between intra- and intermolecular forces; structures of (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, S-(2-nitrophenyl)benzenecarbothiolate and 1-(2-nitrophenylthio)-2,5-pyrrolidinedione

2000 ◽  
Vol 56 (1) ◽  
pp. 58-67 ◽  
Author(s):  
John N. Low ◽  
Emily J. Storey ◽  
Mary McCarron ◽  
James L. Wardell ◽  
George Ferguson ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Nitro Group ◽  
Intermolecular Forces ◽  
Aryl Ring ◽  
Local Energy Minimum ◽  
Conformational Preferences ◽  
A Chain ◽  
Related Compounds ◽  
Scf Calculations ◽  
Intramolecular Forces

In (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, C15H13NO2S (1) (orthorhombic Pbca), the nitro group is almost coplanar with the adjacent aryl ring, but the dihedral angles between the nitro-aryl and styryl fragments is ∼121°. The molecules are linked by paired C—H...O hydrogen bonds in a chain of rings. In S-(2-nitrophenyl)benzenecarbothiolate, C13H9NO3S (2) (monoclinic P21/a), the nitro group is rotated by 33.0 (2)° out of the plane of the adjacent aryl ring and the thiobenzoate group is strongly twisted away from the plane of the disubstituted aryl ring. The molecules of (2) are linked into chains by C—H...O hydrogen bonds, and each chain is linked to two neighbouring chains by means of aromatic π...π stacking interactions. In 1-(2-nitrophenylthio)-2,5-pyrrolidinedione, C10H8N2O4S (3) (monoclinic P21/a), the nitro group is again almost coplanar with the adjacent aryl ring, but the pyrrolidinedione unit is almost orthogonal to the O2NC6H4SN plane. There are three types of C—H...O hydrogen bond in the structure, and these link the molecules into a two-dimensional net. The conformations of these molecules have been investigated by SCF calculations and two energy minima have been identified for each: the molecules of (1) and (3) adopt conformations in their crystals which are close to those at the overall energy minima calculated for isolated molecules, while molecules of (2) adopt a conformation in the crystal close to that calculated for the local energy minimum. Comparisons are made with the structures of some related compounds and it is concluded that, while the nature of the two conformational minima is determined by intramolecular forces, the choice between them is determined primarily by intermolecular forces.

scholarly journals Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low NO<sub><i>x</i></sub> conditions

2016 ◽  
Author(s):  
L. Li ◽  
P. Tang ◽  
S. Nakao ◽  
D. R. Cocker III
Keyword(s):  
Molecular Structure ◽  
Chemical Composition ◽  
Aromatic Hydrocarbon ◽  
Chain Length ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Ortho Position ◽  
Aerosol Formation ◽  
The Impact

Abstract. The molecular structure of volatile organic compounds (VOC) determines their oxidation pathway, directly impacting secondary organic aerosol (SOA) formation. This study comprehensively investigates the impact of molecular structure on SOA formation from the photooxidation of twelve different eight to nine carbon aromatic hydrocarbons under low NOx conditions. The effects of the alkyl substitute number, location, carbon chain length and branching structure on the photooxidation of aromatic hydrocarbons are demonstrated by analyzing SOA yield, chemical composition and physical properties. Aromatic hydrocarbons, categorized into five groups, show a yield order of ortho (o-xylene and o-ethyltoluene) > one substitute (ethylbenzene, propylbenzene and isopropylbenzene) > meta (m-xylene and m-ethyltoluene) > three substitute (trimethylbenzenes) > para (p-xylene and p-ethyltoluene). SOA yields of aromatic hydrocarbon photooxidation do not monotonically decrease when increasing alkyl substitute number. The ortho position promotes SOA formation while the para position suppresses aromatic oxidation and SOA formation. Observed SOA chemical composition and volatility confirm that higher yield is associated with further oxidation. SOA chemical composition also suggests that aromatic oxidation increases with increasing alkyl substitute chain length and branching structure. Further, carbon dilution theory developed by Li et al. (2015a) is extended in this study to serve as a standard method to determine the extent of oxidation of an alkyl substituted aromatic hydrocarbon.

Meso-aryl-ß-pyrrolic positions interactions in meso-tetraarylporphyrins: Flat arylporphyrins and building blocks for oligoporphyrins

2004 ◽  
Vol 08 (02) ◽  
pp. 111-119 ◽  
Author(s):  
Henry J. Callot ◽  
Romain Ruppert ◽  
Christophe Jeandon ◽  
Sébastien Richeter
Keyword(s):  
Building Blocks ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Aryl Ring ◽  
Porphyrin Macrocycle ◽  
Uv Visible

Aryl groups bound to the meso positions of porphyrins often react with neighboring groups, in particular ß-acyl groups to give highly diversified monomeric and dimeric new functionalized porphyrins. The products, whose meso-aryl ring approaches coplanarity with the porphyrin macrocycle, show large shifts of UV-visible absorption bands and various potentialities for building external chelating moieties and assembling oligoporphyrins.

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