Design, synthesis, and antiviral evaluation of some polyhalogenated indole C-nucleosides

Dihydropyrrole-3-thiones: one-pot synthesis from propargylamines, acyl chlorides and sodium sulfide

An efficient one-pot synthesis of 1,2,5-trisubstituted-1,2-dihydro-3H-pyrrole-3-thiones (up to 91% yield), representatives of essentially new heterocyclic systems, by the successive treatment of available propargylamines with acyl chlorides (PdCl2/CuI/Ph3P/Et3N, toluene, 40-45 °C, 3 h) and sodium sulfide (Na2S·9H2O, EtOH, 20-25 °C, 7 h) has been developed. The synthesis comprises the addition of sulfide anions to the formed aminoacetylenic ketones followed by dehydrative cyclization of the prototropically rearranged adducts.

Green Halogenation of Indoles with Oxone-Halide

Oxidative functionalization of indoles is one of the most widely used approaches to exploit the synthetic utility of indoles. In continuation of our research interest in the green oxidation of indoles, we further explore the oxidation of indoles with oxone-halide and discover that the protecting group on the nitrogen of indoles plays a decisive role in controlling the pathways of indole oxidation with oxone-halide. An electron-withdrawing group on the nitrogen of indoles (N-EWG) enables C2 halogenation with stoichiometric halide, while C3 halogenation could be selectively achieved by using stoichiometric halide without dependence on the electronic property of the protecting group on the indole nitrogen. Different from our previous results obtained by using catalytic halide, these findings lead to the development of an environmentally friendly, efficient, and mild protocol for access to 2- or 3-haloindoles (chloro and bromo). As compared to the previous synthetic methods for 2-/3-haloindoles, our method exploits the in situ-generated reactive halogenating species from oxone-halide for halogenation of indoles and thus eliminates the use of stoichiometric halogenating agents and the production of toxic and hazardous organic byproducts derived from oxidants.

Synthesis, Antioxidant, Antimicrobial, Antimycobacterial, and Cytotoxic Activities of Azetidinone and Thiazolidinone Moieties Linked to Indole Nucleus

2-N-(2-Phenyl-1H-indol-3-yl)imino-4-arylthiazoles (3a–c) were used as key synthons for the preparation of (4-arylthiazol-2-yl)-4-(2-phenyl-1H-indol-3-yl)azetidin-2-ones (4a–c) and 3-(4-arylthiazol-2-yl)-2-(2-phenyl-1H-indol-3-yl)thiazolidin-4-ones (5a–c). These newly synthesized compounds have been characterized with the help of IR,1H NMR,13C NMR, and mass spectral studies. All compounds were screened for their antioxidant, antimicrobial, antimycobacterial, and cytotoxic activities. Some of the compounds displayed excellent activity.

Synthesis and anti-HIV activity of 4'-modified cyclopentenyl pyrimidine C-nucleosides

Novel syntheses of 4'-modified cyclopentenyl pyrimidine C-nucleosides were performed via C-C bond formation using S(N)2 alkylation via the key intermediate mesylates 6 and 16, which were prepared from acyclic ketone derivatives. When antiviral evaluation of synthesized compound was performed against various viruses such as HIV-1, HSV-1 and HSV-2, isocytidine analogue 20 showed moderate anti-HIV activity in CEM cell line (EC(50) = 13.1 micromol).

First synthesis and anti-HIV evaluation of 4'-methyl-cyclopentanyl 9-deazaadenosine

The first synthesis of a 4'-methylated carbocyclic C-nucleoside 16 was achieved via the mesylate intermediate 10, which was prepared using ring-closing metathesis and S(N)2 alkylation from acetol 5. When antiviral evaluation of synthesized compound 16 was performed against various viruses such as HIV, HSV-1, HSV-2, and HCMV, it showed moderate anti-HIV activity in MT-4 cell line (EC(50) = 14.7 micromol).

Synthesis and antimicrobial activity of some cyclic and acyclic nucleosides of thieno[2,3-d]pyrimidines

The reaction of compounds 1, 2, 3, 4, or 13 with 2-chloroethyl methyl ether or 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide, afforded some acyclic and cyclic nucleosides of thieno[2,3-d]pyrimidine derivatives. Furthermore, cyclic C-nucleosides 24 and 25 were prepared from the reaction of 20, 21 or from 26, 27 with D-glucose. The antimicrobial evaluation of some prepared products showed promising antimicrobial activity.