Hua-Li Qin

Palladium-catalyzed Mizoroki–Heck-type reactions of [Ph2SRfn][OTf] with alkenes at room temperature

The first Pd-catalyzed Mizoroki-Heck-type reaction of [Ph2SRfn][OTf] with alkenes is described. The reaction of [Ph2SRfn][OTf] (Rfn = CF3, CH2CF3) with alkenes in the presence of 10 mol% Pd[P(t-Bu)3]2 and TsOH at room temperature provided the corresponding phenylation products in good to high yields. The bases that benefit the traditional Mizoroki-Heck reactions severely inhibited the transformation with [Ph2SRfn][OTf], whereas acids significantly improved the reaction. This protocol supplies a new class of cross-coupling partners for Mizoroki-Heck-type reactions and gains important insights into the reactivity of phenylsulfonium salts either with or without fluorine-containing alkyl groups as the promising phenylation reagents in organic synthesis.

Aryl fluorosulfate analogues as potent antimicrobial agents: SAR, cytotoxicity and docking studies

A series of aryl fluorosulfate analogues (1-37) were synthesized and tested for in vitro antibacterial and antifungal studies, and validated by docking studies. The compounds 9, 12, 14, 19, 25, 26, 35, 36 and 37 exhibited superior antibacterial potency against tested bacterial strains, while compounds 2, 4, 5, 15, 35, 36 and 37 were found to have better antifungal activity against tested fungal strains, compared to standard antibiotic gentamicin and ketoconazole respectively. Among all the synthesized 37 analogs, compounds 25, 26, 35, 36 and 37 displayed excellent anti-biofilm property against Staphylococcus aureus. The structure-activity relationship (SAR) revealed that the antimicrobial activity depends upon the presence of -OSO2F group and slender effect of different substituents on the phenyl rings. The electron donating (OCH3) groups in analogs increase the antibacterial activity, and interestingly the electron withdrawing (Cl, NO2, F and Br) groups increase the antifungal activity (except compound 35, 36 and 37). The mechanism of potent compounds showed membrane damage on bacteria confirmed by SEM. Compounds 35, 36 and 37 exhibited highest glide g-scores in molecular docking studies and validated the biocidal property.