Intercropping of wheat/faba bean is a common practice within the legume-cereal family. However, the benefits of nitrogen (N) fertilizer-optimized synergistic intercropping in improving faba bean productivity while controlling the prevalence of chocolate spot disease have not been established. This study conducted continuous field experiments spanning two planting seasons to investigate two key findings: (i) Optimizing N fertilizer application can enhance the productivity of intercropped faba bean.
View Article and Find Full Text PDFBackground: The aim is to study the disease suppression efficiency, yield loss rate, and yield benefits of intercropped faba bean against chocolate spot under nitrogen (N) input, to clarify the effectiveness of intercropping faba beans in controlling chocolate spot and its contribution to yield increase.
Results: Four N input levels and disease suppression treatments were discovered when faba bean-wheat intercropped was used. Adding N enhanced the chocolate spot's area under disease progression curve (AUDPC) by 27.
The catalytic anti-Markovnikov addition of alcohols to simple alkenes is a longstanding synthetic challenge. We recently disclosed the use of organic superbase catalysis for the nucleophilic addition of alcohols to activated styrene derivatives. This article describes mechanistic studies on this reversible reaction, including thermodynamic and kinetic profiling as well as computational modeling.
View Article and Find Full Text PDFWhile intercropping can help control faba bean rust, the ability of intercropping to reduce this disease under different levels of nitrogen fertilization and its contribution to increasing yield is not clear. In this study, two planting patterns of faba bean monocropping and wheat/faba bean intercropping, together with two treatments for disease control and noncontrol, and four nitrogen application levels (N [0 kg/ha], N [45 kg/ha], N [90 kg/ha], and N [135 kg/ha]) were tested for 2 years in a continuous field experiment. The results revealed that nitrogen application increased the area under the disease progress curve (AUDPC) of faba bean rust from 41.
View Article and Find Full Text PDFChanges in the light environment have an important effect on crop growth and yield. To clarify the effects of intercropping and the application of nitrogen on the yield of wheat and light within the crop canopy, the relationship between light and yield and their response to nitrogen fertilizer were studied. In a 2-year field experiment, the characteristics of growth, light, biomass, and yield of wheat were measured using three cropping arrangements (monocropped wheat, monocropped faba beans, and intercropped wheat/faba beans) and four levels of applied nitrogen, in groups termed N (0 kg/ha), N (90 kg/ha), N (180 kg/ha), and N (270 kg/ha).
View Article and Find Full Text PDFOff-target effects continue to impede disease interventions, particularly when targeting a specific protein within a family of similar proteins, such as kinase isoforms that play tumor-subtype-specific roles in cancers. Exploiting the specific electrophilic-metabolite-sensing capability of Akt3, versus moderate or no sensing, respectively, by Akt2 and Akt1, we describe a first-in-class functionally Akt3-selective covalent inhibitor [MK-H(F)NE], wherein the electrophilic core is derived from the native reactive lipid metabolite HNE. Mechanistic profiling and pathway interrogations point to retention of the metabolite's structure-as opposed to implicit electrophilicity-as being essential for biasing isoform preference, which we found translates to tumor-subtype specificity against -null triple-negative breast cancers (TNBCs).
View Article and Find Full Text PDFWe report a fluoride-initiated coupling reaction between trifluoromethylarenes and allylsilanes to access allylated α,α-difluorobenzylic compounds. This method's utility is demonstrated through a 30 mmol scale reaction, a sequential allylation/derivatization protocol and multiple examples of site-selective trifluoromethylarene allylation. Initial mechanistic studies suggest a base-induced single electron transfer pathway is responsible for the high efficiency and selectivity of this novel C-F substitution process.
View Article and Find Full Text PDFThe organic superbase P- t-Bu catalyzes the direct anti-Markovnikov addition of alcohols to aryl alkenes to access valuable β-phenethyl ethers. A diverse substrate scope of aryl alkenes and alcohols is demonstrated, including heterocyclic systems and unprotected aminoalcohols. Mechanistic studies reveal that the reaction is under equilibrium control and extensive comparisons to common inorganic bases indicate that the broad reaction scope is uniquely enabled through the use of the organic superbase.
View Article and Find Full Text PDFThis report details a new method for site-selective methylene oxidation adjacent to azaheterocycles. A dual catalysis approach, utilizing both an iron Lewis acid and an organic hydroxylamine catalyst, proved highly effective. We demonstrate that this method provides complementary selectivity to other known catalytic approaches and represents an improvement over current heterocycle-selective reactions that rely on stoichiometric activation.
View Article and Find Full Text PDFEnantioselective α-alkylation of carbonyl is considered as one of the most important processes for asymmetric synthesis. Common alkylation agents, that is, alkyl halides, are notorious substrates for both Lewis acids and organocatalysts. Recently, olefins emerged as a benign alkylating species via photo/radical mechanisms.
View Article and Find Full Text PDFTetrahydroquinolines containing two quaternary stereogenic centers were synthesized with excellent ee and dr via a four-component cyclization reaction catalyzed by a chiral phosphoric acid. High chemoselectivity was achieved by differentiating anilines with similar reactivities to yield diverse "hybrid" products. The chirality of the quaternary C4 atom of the 4-aminotetrahydroquinoline products was found to undergo highly stereoselective inversion, enabling facile functionalization using a wide range of nucleophiles (C, O, N, and S).
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