Design, Synthesis, and Evaluation of 7‐Vinylcoumarin Derivatives as Agrochemicals: Biological Activities and Molecular Docking Insights

The agricultural bioactivity of 7-alkenylcoumarin derivatives was investigated by synthesizing a series of coumarin derivatives containing 7-styryl fragments by introducing a styryl group at the 7-position of the coumarin scaffold through Pechmann cyclization, substitution, bromination, and Wittig reaction. The insecticidal effects and antifungal activities of these compounds against plant pathogenic fungi were evaluated. Bioactivity assessments revealed that compound 5i exhibited the highest larvicidal activity against Aedes aegypti, with a mortality rate of 96% after 24 h of treatment. Compounds 5i, 5e, and 5a displayed the strongest antifungal activity against Colletotrichum musae, with median effective concentration values of 0.42, 3.44, and 3.67 mg/L, respectively, outperforming the commercial fungicide bromothalonil (9.31 mg/L) and comparable to chlorothalonil (0.74 mg/L). Structure-activity relationship analysis indicated that the presence of a chlorine atom at the 4-position of the phenyl ring was critical for the bioactivity of the compounds. Docking results indicated that compound 5i exhibited the strongest binding affinity for succinate dehydrogenase, providing insights for further mechanistic studies. These findings suggest the significant potential of these compounds as lead candidates for in-depth research and development.