One-pot synthesis of 3-aminofurans using a simple and efficient recyclable CuI/[bmim]PF6 system.

A one-pot three-component reaction of several 2-ketoaldehydes, secondary amines and terminal alkynes to access 3-aminofurans proceeded well in [bmim][PF6] using a simple and cheap CuI catalyst. The resultant 3-aminofuran products were easily isolated using diethyl ether and the CuI/[bmim][PF6] system was reused six times with a slight decrease in the activity.

Gold mediated sp3αC-H functionalization of steroidal diglycoside and their anti-cancer evaluation.

C(sp3)-H alkylation at α-position of methyl-keto group on D-ring of Steroidal diglycoside (SG) with (i) C=N of Schiff base imines to form amine derivatives and (ii) C=C of acrylate Michael acceptors to form Markovnikov ester products using AuCl3/NHC as pre-catalyst and Ag(I) salts as co-catalyst was described. The original form of SG (1) and its derivatives (3b-f & 5a-d) were screened for in vitro anti-cancer activity specifically on two breast cancer cell lines (i.e. MCF-7, MDA-MB-231) and deduced the structure-activity-relationship with the support of molecular docking studies. Among these compounds 3b, 3f, 5b & 5d have shown more potent anticancer activity than standard drug cisplatin with considerable IC50 values.

Design and synthesis of 4ß-Acetamidobenzofuranone-podophyllotoxin hybrids and their anti-cancer evaluation.

A new series of amide derivatives of 4ß-Acetamidobenzofuranone-podophyllotoxin hybrids (14a-g) were synthesized and their chemical structures were confirmed by 1H, 13C NMR and mass spectral data. Further, all the synthesized Acetamidobenzofuranone-podophyllotoxin hybrids were evaluated for in vitro cytotoxic activity against a panel of four human cancer cell lines i.e., human breast (MCF-7, MDA MB-231), lung (A549), and prostrate (DU-145). Among benzofuranone-podophyllotoxin hybrid compounds, 14b and 14e were exhibited more potent activity than standard drug and 14c and 14f were showed anticancer activity equivalent to etoposide.

Silver carbene complexes: An emerging class of anticancer agents.

Cancer is a major global health problem with large therapeutic challenges. Although substantial progress has been made in cancer therapy, there still remains a need to develop novel and effective treatment strategies to treat several relapsed and refractory cancers. Recently, there has been growing demand for considering organometallics as antineoplastic agents. This review is focused on a group of organometallics, silver N-heterocyclic carbene complexes (SCCs) and their anticancer efficacy in targeting multiple pathways in various in vitro cancer model systems. However, the precise molecular mechanism of SCCs anticancer properties remains unclear. Here, we discuss the SCCs chemistry, potential molecular targets, possible molecular mechanism of action, and their application in cancer therapies.

Highly Efficient and Practical N-Heterocyclic Carbene Organocatalyzed Chemoselective N1/C3-Functionalization of Isatins with Green Chemistry Principles.

Ecofriendly N-heterocyclic carbene (NHC) organocatalysis can control the N1-functionalization (aza-Michael addition) and C3-functionalization (Morita-Baylis-Hillman reaction, MBH) of isatins in the absence of (1) a protecting group, (2) a stoichiometric reagent, and (3) heat energy. The challengeable N1-functionalization of N-unsubstituted isatins into N-substituted (NS) isatins was realized through 10 mol % NHC and 10 mol % 1,8-diazabicyclo[5.4.0]undec-7-ene catalysts within 10 min with up to 98% isolation yield. The subsequent MBH adducts of as-synthesized NS-isatins (N1/C3-functionalization) was perfectly acquired in 10 mol % NHC and 10 mol % 1,4-diazabicyclo[2.2.2]octane catalysis within 30 min with superiority to C3/N1-functionalization (MBH/aza-Michael). For guiding the application to a versatile druggable isatin library, the NHC catalysis was compared with reported functionalization of isatins in view of green chemistry principles including solvent scoring of ACS GCI pharmaceutical roundtable, E-factor, atom economy, and so on.

Pd-N-heterocyclic carbene catalyzed synthesis of piperidine alkene-alkaloids and their anti-cancer evaluation.

A facile synthesis of piperidine alkene-alkaloids including natural (+)-Caulophyllumine B in high yields has been developed by Heck cross-coupling reaction catalyzed by simple in situ formed palladium-N-heterocyclic carbenes (Pd-NHCs). Formation of Pd(0) nanoparticles has been noticed during the reaction course. The synthesized piperidine alkene-alkaloids were evaluated for in vitro anti-cancer activity against a panel of human tumor cell lines of lung, breast and ovarian. Several of these piperidine alkene-alkaloids were found to possess highest growth inhibition activity than the standard drug cisplatin and support the concept to modulate drug receptor interaction.

Regioselective synthesis of isoxazole-mercaptobenzimidazole hybrids and their in vivo analgesic and anti-inflammatory activity studies.

Regioselective synthesis of isoxazole-mercaptobenzimidazole hybrids and their efficiency in in vivo analgesic and anti-inflammatory activity was described. A comparison of structure-activity relationship for there compounds was also emphasized.

N-heterocyclic carbene-catalyzed 1,3-dipolar cycloaddition reactions: a facile synthesis of 3,5-di- and 3,4,5-trisubstituted isoxazoles.

A first example of organo-N-heterocyclic carbene (NHC) catalyzed click-type fast 1,3-dipolar cycloaddition of nitrile oxides with alkynes was developed for the regioselective synthesis of 3,5-di- and 3,4,5-trisubstituted isoxazoles. Triethylamine (Et(3)N) was employed as an effective base to generate both nitrile oxide and the organo-NHC catalyst in situ. This catalytic approach was used to attach a variety of substituents, including other biologically active fragments, onto the isoxazole ring to selectively design multinucleus structures. Further, we have also optimized the conditions for Cu(I)-free Sonogashira cross-coupling to obtain internal alkynes in high yields, which were subsequently used in cycloaddition. A catalytic cycle is proposed and the remarkable regiocontrol in the formation of isoxazoles was ascribed to a beneficial zwitterion intermediate developed by the interaction of the strongly nucleophilic organo-NHC catalyst with alkyne followed by nitrile oxide.

Synthesis, characterization and biological evaluation of mononuclear Co(II), Ni(II), Cu(II) and Pd(II) complexes with new N2O2 Schiff base ligands.

New tetradentate N(2)O(2) donor Schiff bases and their mononuclear Co(II), Ni(II), Cu(II), and Pd(II) complexes were synthesized and characterized extensively by IR, (1)H-, (13)C-NMR, mass, ESR, conductivity measurements, elemental and thermal analysis. Specifically the magnetic and electronic spectral measurements demonstrate the octahedral structures of cobalt(II), nickel(II) complexes and square planar geometries of copper(II), palladium(II) complexes. All the ligands and complexes were screened for their in vitro antibacterial activity against two gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Klebsiella pneumonia). In this study, Pd(II) complexes exhibited potent antibacterial activity against B. subtilis, S. aureus whereas other metal complexes also exerted good activity towards all tested strains even than standard drugs streptomycin and ampicillin.