Visible-Light-Driven Halogen-Bond-Assisted Direct Synthesis of Heteroaryl Thioethers Using Transition-Metal-Free One-Pot C–I Bond Formation/C–S Cross-Coupling Reaction
involves two sequential reactions in a single pot where the formation of the iodinated heteroarene is followed by a transition-metal-free C–S coupling reaction. A wide range of heteroarene and thiol partners (including aliphatic thiols) have been used for the synthesis of thioethers. NMR studies and DFT calculations revealed the presence of a halogen bond between the thiolateanion (halogen bond acceptor)
Optimization of 3-(phenylthio)quinolinium compounds against opportunistic fungal pathogens
作者:Comfort A. Boateng、Xue Y. Zhu、Melissa R. Jacob、Shabana I. Khan、Larry A. Walker、Seth Y. Ablordeppey
DOI:10.1016/j.ejmech.2011.02.034
日期:2011.5
Ring-opened benzothieno[3,2-b]quinolinium salts (3) were designed and synthesized with substitution on the thiophene moiety. In vitro screenings were carried out against fungal pathogens including Cryptococcus neoformans, Candida albicans, Candida glabrata, Candida krusei and Aspergillus fumigatus. In all, by replacing the N-methyl group (2) with N-omega-phenylpentyl or omega-cyclohexylpentyl group to form substituted 3-(phenylthio)quinolinium compounds produced remarkable potencies, as high as 300-fold (cf. cryptolepine (1) = 250 mu g/mL vs lip = 0.8 mu g/mL for C. albicans) over the starting tetracyclic parent. In addition, all the N-omega-cyclohexylpentyl analogs produced superior activity against all the microorganisms tested than the N-omega-phenylpentyl substituted compounds. The potential of these compounds to induce toxicity in Vero cells was also investigated and the majority of them showed lower or no cytotoxicity at 10 mu g/mL than amphotericin B. the gold standard in antifungal drug development. For instance, the trifluoromethyl substituted analogs (11n-p) have selectivity indices over 2-fold better than those of amphotericin B in C. neoformans. Overall, this ring-opened scafford of benzothienoquinolines, with substitution on the thiophenyl moiety, serves as a new lead for further development. Published by Elsevier Masson SAS.
Metallaphotoredox-Catalyzed C–S Cross-Coupling between Heteroaryl Bromides and α-Thioacetic Acids to Access Biaryl Thioethers
作者:Alec H. Christian
DOI:10.1021/acs.joc.1c01309
日期:2021.8.6
Structural Simplification of Cryptolepine to Obtain Novel Antifungal Quinoline Derivatives against Phytopathogenic Fungi