Synthesis, crystal structure, and biological activities of 2-cyanoacrylates containing furan or tetrahydrofuran moieties

A series of novel cyanoacrylates containing furan or tetrahydrofuran moieties were synthesized, and their structures were characterized by H-1 NMR, elemental analysis, and single-crystal X-ray diffraction analysis. The herbicidal, plant growth regulatory, fungicidal, and antiviral activities of these cyanoacrylates were evaluated. The results of herbicidal activities showed that most of these cyanoacrylates exhibited higher herbicidal activities against dicotyledonous weeds than monocotyledonous weeds, and the compounds containing the tetrahydrofuran moiety gave higher herbicidal activities than corresponding furan analogues; (Z)-ethoxyethyl 2-cyano-3-isopropyl-3-(tetrahydrofuran-3-yl) methaneaminoacrylate showed excellent herbicidal activities against amaranth pigweed in postemergence treatment at a dose of 375 g/ha. At the same time, these cyanoacrylates had interesting plant growth regulatory activities, and some compounds stimulated radicle growth of cucumber, whereas some compounds had an inhibitory effect. These cyanoacrylates showed fungicidal activities as well.