@article { ISI:000237485300010, title = {Ligand-, copper-, and amine-free one-pot synthesis of 2-substituted indoles via Sonogashira coupling 5-endo-dig cyclization}, journal = {Tetrahedron}, volume = {62}, number = {21}, year = {2006}, month = {MAY}, pages = {5109-5115}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Results of the optimized conditions for the one-pot synthesis of 2-substituted indoles via palladium acetate catalyzed tandem Sonogashira coupling 5-endo-dig cyclization at room temperature under ultrasonic irradiation and standard stirred conditions are described. Electron-donating and electron-withdrawing groups present in both Coupling partners were well tolerated under these mild conditions. A copper-, ligand- and amine-free condition is an important feature of this protocol. Significant enhancement of reaction rates was observed for the reactions employing ultrasonic irradiation. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {5-endo-dig cyclization, Indole, synthesis, Ultrasound}, issn = {0040-4020}, doi = {10.1016/j.tet.2006.03.035}, author = {Palimkar, Sanjay S. and Kumar, P. Harish and Lahoti, Rajgopal J. and Srinivasan, Kumar V.} } @article { ISI:000271280200036, title = {Short synthesis of 3,6-disubstituted N-2-thienyl/aryl-indoles}, journal = {Tetrahedron Letters}, volume = {50}, number = {47}, year = {2009}, month = {NOV}, pages = {6562-6566}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A short synthetic strategy for 3,6-disubstituted-N-2-thienyl/aryl-indoles, involving reaction of substituted 2,4-difluoro/dichloro-styrene epoxide with substituted 2-formylaminothiophenes or substitued N-formylanilins in the presence of a base followed by treatment with an acid, has been developed The method was applied for the synthesis of a number of indoles with a variety of substitutents at 1, 3, and 6 positions of the indole moiety. (C) 2009 Elsevier Ltd All rights reserved.

}, keywords = {Formylaminothiophene, Gewald synthesis, Indole, Styrene epoxide}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2009.09.049}, author = {Borate, Hanumant B. and Sawargave, Sangmeshwer P. and Maujan, Suleman R.} } @article { ISI:000350754400004, title = {Target cum flexibility: synthesis of indolo[1,2-b]isoquinoline derivatives via cobalt-catalyzed [2+2+2] cyclotrimerization}, journal = {Synlett}, volume = {26}, number = {5}, year = {2015}, month = {MAR}, pages = {604-608}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A modular approach for the synthesis of small molecules having the unnatural 6,11-dihydroindolo[1,2-b]isoquinoline tetracyclic core has been documented. An acid-catalyzed Friedel-Crafts-type C2-alkylation of N-propargyl indole with a suitably activated alkynol has been used to prepare the key indole-derived diynes. The cobalt-catalyzed [2+2+2] cyclotrimerization of these diynes has been studied with various internal/terminal alkynes and with nitriles.

}, keywords = {2-b]-isoquinoline, cobalt, Indole, indolo[1, Pyridine, [2+2+2] cyclotrimerization}, issn = {0936-5214}, doi = {10.1055/s-0034-1379950}, author = {Swami, Anuradha and Ramana, Chepuri V.} } @article { ISI:000371344600027, title = {Synthesis, biological evaluation and molecular docking study of some novel indole and pyridine based 1,3,4-oxadiazole derivatives as potential antitubercular agents}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {26}, number = {7}, year = {2016}, month = {APR }, pages = {1776-1783}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A series of indole and pyridine based 1,3,4-oxadiazole derivatives 5a-t were synthesized and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Ra (MTB) and Mycobacterium bovis BCG both in active and dormant state. Compounds 5b, 5e, 5g and 5q exhibited very good antitubercular activity. All the newly synthesized compounds 5a-t were further evaluated for antiproliferative activity against HeLa, A549 and PANC-1 cell lines using modified MTT assay and found to be noncytotoxic. On the basis of cytotoxicity and MIC values against Mycobacterium bovis BCG, selectivity index (SI) of most active compounds 5b, 5e, 5g and 5q was calculated (SI = GI(50)/MIC) in active and dormant state. Compounds 5b, 5e and 5g demonstrated SI values \>= 10 against all three cell lines and were found to safe for advance screening. Compounds 5a-t were further screened for their antibacterial activity against four bacteria strains to assess their selectivity towards MTB. In addition, the molecular docking studies revealed the binding modes of these compounds in active site of enoyl reductase (InhA), which in turn helped to establish a structural basis of inhibition of mycobacteria. The potency, low cytotoxicity and selectivity of these compounds make them valid lead compounds for further optimization. (C) 2016 Elsevier Ltd. All rights reserved.

}, keywords = {1, 3, 4-Oxadiazole, Antitubercular activity, Cytotoxicity, Indole, Molecular docking, Pyridine}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2016.02.043}, author = {Desai, N. C. and Somani, Hardik and Trivedi, Amit and Bhatt, Kandarp and Nawale, Laxman and Khedkar, Vijay M. and Jha, Prakash C. and Sarkar, Dhiman} } @article {46415, title = {C-H functionalization of indoles by 3d transition-metal catalysis}, journal = {Asian Journal of Organic Chemistry}, year = {2019}, month = {DEC}, type = {Review; Early Access}, abstract = {

Over the past decade, the use of 3d transition metal for the regioselective C-H bond functionalization of indoles has significantly increased. Particularly, advances in manganese, iron, cobalt, nickel and copper catalysis have demonstrated the selective C(2)-H and C(3)-H arylation, alkenylation, alkynylation and alkylation to a greater extent. Similarly, the C-O and C-N bond-forming reactions are manifested via direct C-H bond activation by these earth-abundant metals. The emergence of 3d metals in selective functionalization of the biologically relevant indoles and related heteroarenes would make this protocol more attractive for practical applications. Herein, we provide a brief overview of 3d transition metal-catalyzed (mostly Mn, Fe, Co, Ni and Cu) C-H functionalization of indoles and related heteroarenes.

}, keywords = {3d transition metal, C-H functionalization, Indole, indoline}, issn = {2193-5807}, doi = {10.1002/ajoc.201900554}, author = {Jagtap, Rahul A. and Punji, Benudhar} } @article {46884, title = {Copper-catalyzed direct arylation of indoles and related (hetero)arenes: a ligandless and solvent-free approach}, journal = {Advanced Synthesis \& Catalysis}, volume = {362}, year = {2020}, month = {JUN }, pages = {2534-2540}, type = {Article}, abstract = {

A ligandless and solvent-free copper-catalyzed method for the regioselective C-H bond arylation of indoles and related heteroarenes is reported. The use of CuCl efficiently catalyzes the direct coupling of diverse heteroarenes with aryl iodides via chelation-assistance. This reaction could tolerate sensitive and structurally diverse functionalities, including halides, ethers, thioethers, amines, indolyl, pyrrolyl and carbazolyl groups. The directing group, 2-pyridinyl can be smoothly removed to generate C-2 arylated free-NH indoles, and the arylated indoles can further be functionalized into Tryptamine derivatives. Preliminary mechanistic study revealed a radical pathway for the arylation reaction.

}, keywords = {Arylation, C-H activation, Chelation-assistance, Copper, Indole, Solvent-free}, issn = {1615-4150}, doi = {10.1002/adsc.202000312, Early Access Date = APR 2020}, author = {Pandey, Dilip K. and Shabade, Anand B. and Punji, Benudhar} } @article {47704, title = {Phosphine-free manganese(II)-catalyst enables acceptorless dehydrogenative coupling of alcohols with indoles}, journal = {Advanced Synthesis \& Catalysis}, volume = {363}, year = {2021}, month = {SEP }, pages = {4430-4439}, type = {Article}, abstract = {Herein, an air-stable, molecularly defined NNN-Mn(II) pincer complex catalyzed acceptorless dehydrogenative coupling of alcohols with indoles is reported. A wide variety of symmetrical and unsymmetrical bis(indolyl)methane derivatives as well as some structurally important products such as Vibrindole A, Turbomycin B alkaloid, Antileukemic, and Anticancer agents were synthesized. Mechanistic studies illustrate the importance of the NH moiety in the complex and the crucial role of metal-ligand cooperation during catalysis.}, keywords = {acceptorless dehydrogenation, Alcohol, Indole, manganese, phosphine-free}, issn = {1615-4150}, doi = {10.1002/adsc.202100621}, author = {Yadav, Vinita and Balaraman, Ekambaram and Mhaske, Santosh B.} } @article {48224, title = {Design, synthesis of anticancer and anti-inflammatory 4-(1-methyl-1H-indol-3-yl)-6-(methylthio) pyrimidine-5-carbonitriles}, journal = {Synthetic Communications}, volume = {52}, year = {2022}, month = {MAR }, pages = {733-744}, type = {Article}, abstract = {

A novel series of 4-(1-methyl-1H-indol-3-yl)-6-(methylthio) pyrimidine-5-carbonitriles (4a-i) was synthesized and evaluated for anticancer potential against cell lines for breast cancer. Compounds 4b, 4e, and 4h exhibited prominent cytotoxicity against human breast carcinoma MCF-7 cell line with GI(50 )of 2.0, 0.5, and 0.5 mu M, respectively. Molecular docking study against EGFR tyrosine kinase could provide valuable insights into the plausible mechanism of action. The compounds could bind with significantly high binding affinity and their binding affinity scores could correlate well with the observed anticancer activity. Furthermore, compounds 4a, 4c, 4e, 4g, and 4i exhibited significant inflammatory activities as well which could expand the therapeutic domain of this novel series.

}, keywords = {Anti-inflammatory, Anticancer, Antioxidant, Indole, pyrimidine}, issn = {0039-7911}, doi = {10.1080/00397911.2022.2048860}, author = {Bhale, Pravin S. and Chavan, V. Hemant and Shringare, Sadanand N. and Khedkar, Vijay M. and Tigote, Radhakrishna M. and Mali, Nikita N. and Jadhav, Tukaram D. and Kamble, Nitin B. and Kolat, Swati P. and Bandgar, Babasaheb P. and Patil, Harshal S.} }