Protoporphyrinogen‐IX‐oxidase Inhibitors

Synthesis, Herbicidal Activity, and QSAR of Novel N-Benzothiazolyl- pyrimidine-2,4-diones as Protoporphyrinogen Oxidase Inhibitors

“…7 In contrast to herbicides with other modes of action, PPO herbicides have many advantages such as low userate, broad herbicidal spectrum, quick onset of action, long lasting effect, and environmentally benign characteristics. 8 Among the chemical families mentioned above, pyrimidinedione derivatives have attracted considerable attention in the field of agrochemistry during recent decades. 9 Butafenacil, 10 benzfendizone, 11,12 and saflufenacil 13 (Figure 1) are three representative commercialized pyrimidinedione type herbicides.…”

“…These herbicides can cause peroxidative destruction of the cellular membrane by blocking the oxidation of a protogen which is a prerequisite step for the synthesis of chlorophylls and bleaching of plant tissues in the presence of light . In contrast to herbicides with other modes of action, PPO herbicides have many advantages such as low use-rate, broad herbicidal spectrum, quick onset of action, long lasting effect, and environmentally benign characteristics …”

“…For the pyrimidine ring unit, it is clear that substituting a methyl group at the N1-position and a trifluoromethyl in the C6-position at the same time always results in better activity . Additionally, linking the substituents at the 4′- and 6′-positions together or assembling the 6′-position and 7′-position of the phenyl ring to furnish a benzoheterocyclic ring was demonstrated to be an effective strategy for discovering novel protoporphyrinogen oxidase inhibitors . Two notable examples of this ring-closure strategy are commercial herbicides flumioxazin and thiadiazimin, in which benzooxazin-3-one was introduced by assembling the substituent at the C-4′ and C-6′ into a six-membered oxazinone ring.…”

Discovery, SAR, and putative mode of action of N‐benzyl‐2‐methoxybenzamides as potential bleaching herbicides

“…Further analysis suggested that an electronic effect of the substituent on the benzylamine moiety had little impact on herbicidal activity. For example, the 3-methylbenzylamine derivative (16) showed activity comparable with that of fluorinated benzylamine derivatives (3,4,7). It seems that the herbicidal activity of the derivatives was strongly affected by a steric effect of the substituents on the benzylamine moiety.…”

“…3 Diphenyl ether (nitrofen), oxadiazolinone (oxadiazon) and tetrahydrophthalimide (chlorophthalim) are three classes of PPO inhibitors developed in the 1960s to 1980s, and many other non-classical Protox chemistries have been introduced since. [4][5][6][7] Norflurazon, picolinafen and diflufenican are inhibitors of phytoene desaturase (PDS), which catalyzes the desaturation of phytoene in carotenoid biosynthesis. [8][9][10] Isoxaflutole and mesotrione interfere with the production of homogentisate by inhibiting 4-hydroxyphenylpyruvate dioxygenase (HPPD).…”