Based on the structure of natural product 2-aryl-4,5-dihydrothiazole-4-carboxylic acid, a series of novel (R)-2-aryl-4,5-dihydrothiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were characterized by ¹H NMR, ¹³C NMR and HRMS. The single crystal structure of compound 9b was determined by X-ray diffraction analysis. The antifungal activities were evaluated for the first time. The bioassay results indicated that most compounds exhibited moderate to good antifungal activities. The antifungal activities of compound 13a (against Cercospora arachidicola Hori), 13d (against Alternaria solani), and 16e (against Cercospora arachidicola Hori) were 61.9%, 67.3% and 61.9%, respectively, which are higher than those of the commercial fungicides chlorothalonil and carbendazim. Moreover, compound 13d exhibited excellent antifungal activities against 7 kinds of the fungi tested (66.7%, 77.3%, 63.0%, 87.9%, 70.0%, 70.0% and 80.0% at 50 µg?mL). Therefore, 13d can be used as a new lead structure for the development of antifungal agents.

In order to discover novel insecticides with the new action mode on ryanodine receptor (RyR), a series of novel phthalic acid diamide derivatives were designed and synthesized. All compounds were characterized by ¹H NMR spectra and HRMS. The preliminary results of biological activity assessment indicated that some title compounds exhibited excellent insecticidal activities against Mythimna separata, Spodoptera exigua, and Plutella xylostella. The title compound 3-nitro-N-cyclopropyl-N′-[2-methyl-4-(perfluoropropan-2-yl)phenyl]phthalamide (4a) was more efficient against diamondback moths than the control (chlorantraniliprole). The effects of some title compounds on intracellular calcium of neurons from the Spodoptera exigua proved that the title compounds were RyR activators.

In an attempt to search for potent antifungal agents, a series of novel 1-substituted phenyl-4-[N-[(2′-morpholinothoxy)phenyl]aminomethyl]-1H-1,2,3-triazoles 5a–m was designed and synthesized via Huisgen cycloaddition reaction between various (2-morpholinoethoxy)-N-(prop-2-ynyl)aniline and different azidobenzene. Their chemical structures were characterized by ¹H NMR and elemental analysis. A cleaner reaction with milder conditions and satisfactory yields was observed in the micorwave-assisted synthesis of 4a–c. The fungicidal activity of some target compounds were evaluated in vitro against Fusarium omysporum, Physalospora piricola, Alternaria solani, Cercospora arachidicola and Gibberella zeae at 50 μg/mL. The bioassay results indicated that some compounds exhibited moderate fungicidal activities. Furthermore, compound 5h displayed equal activity to the positive control compounds against Alternaria solani.

A series of 3-thiazolidine acetic acid-2-(per-O-acetylglycosyl)-1′-imino-α-(substituted)-4-oxo ethyl ester derivatives (3a–t) were prepared via the reaction of substituted amino acid-N-[(per-O-acetylglycosylamino)thioxomethyl]-ethyl ester with ethyl bromoacetate. The crystal structure of 3-thiazolidine acetic acid-2-(2′,3′,4′,6′-tetra-O-acetyl-β-d-galactoyranosyl)-1′-imino-α-methyl-4-oxo ethyl ester 3g and ¹H-¹³C HMBC (2D NMR experiments) measurements of 3-thiazolidine acetic acid-2-(2′,3′,4′,6′-tetra-O-acetyl-β-d-galactopyranosyl)-1′-imino-α-(1-methylthio)ethyl-4-oxo ethyl ester 3j revealed the exclusive regioselectivity during the closure of these rings toward the N-2 position of the thiourea moiety. Furthermore, the crystal structure of compound 3g showed that the attack of N-1 was blocked by sugar ring owing to the steric effect. The bioactivity data suggested that compound 2e has mild anticancer activity.