Discovery and structure-activity relationship of dimesulfazet: a novel rice paddy herbicide.

Dimesulfazet, a novel herbicide for use in paddy rice, was discovered during studies on haloalkylsulfonanilide derivatives. Our research revealed that cyclic sulfonamide derivatives exhibited herbicidal efficacy against paddy weeds prevalent in Japan, such as Schoenoplectiella juncoides (Roxb.) Lye. Furthermore, these derivatives showed efficacy against hard-to-control perennial sedges such as Eleocharis kuroguwai Ohwi. Subsequently, we converted the cyclic sulfonamide derivatives into cyclic amide derivatives, which demonstrated enhanced herbicidal activity. Among these derivatives, dimesulfazet was selected because of its exceptional efficacy against both annual and perennial sedges, while being safe for use on transplanted rice. A simple method was developed for the condensation of benzyl alcohol and cyclic amide intermediates to synthesize trifluoromethanesulfonanilide derivatives. We found that the mode of action of dimesulfazet involved the inhibition of very long-chain fatty acid biosynthesis. Dimesulfazet represents a valuable new tool for controlling S. juncoides, including biotypes resistant to acetolactate synthase inhibitors, and other perennial sedges in rice paddies. © 2024 Society of Chemical Industry.

Towards universal neural network potential for material discovery applicable to arbitrary combination of 45 elements.

Computational material discovery is under intense study owing to its ability to explore the vast space of chemical systems. Neural network potentials (NNPs) have been shown to be particularly effective in conducting atomistic simulations for such purposes. However, existing NNPs are generally designed for narrow target materials, making them unsuitable for broader applications in material discovery. Here we report a development of universal NNP called PreFerred Potential (PFP), which is able to handle any combination of 45 elements. Particular emphasis is placed on the datasets, which include a diverse set of virtual structures used to attain the universality. We demonstrated the applicability of PFP in selected domains: lithium diffusion in LiFeSO4F, molecular adsorption in metal-organic frameworks, an order-disorder transition of Cu-Au alloys, and material discovery for a Fischer-Tropsch catalyst. They showcase the power of PFP, and this technology provides a highly useful tool for material discovery.

Domino Friedel-Crafts-type cyclizations of difluoroalkenes promoted by the α-cation-stabilizing effect of fluorine: an efficient method for synthesizing angular PAHs.

In order to synthesize polycyclic aromatic hydrocarbons with nonlinear arrangements (angular PAHs), acid-promoted domino cyclizations of 1,1-difluoroalk-1-enes and 1,1-difluoroalka-1,3-dienes were studied. 1,1-Difluoroalkenes, each bearing two aryl substituents, were regioselectively protonated with FSO(3)H⋅SbF(5) to generate fluorine-stabilized carbocations, which readily underwent domino Friedel-Crafts-type cyclizations to give carbocycles based on 6/n/m/6 ring systems (n,m=5-7) in good to high yields. Protonation of 1,1-difluoroalka-1,3-dienes took place at their electron-rich methylene (CH(2)) carbon atoms in the presence of milder acids such as camphorsulfonic acid and trifluoromethanesulfonic acid. Domino cyclizations of the resulting fluorine-stabilized allylic carbocations afford carbocycles based on 6/6/6/6 or 6/6/5/6 ring systems in high yields.