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Imidazole-4-carhoxamide (ICA), which is one of the groups of 'fairy chemicals' (FCs) that cause the fairy ring phenomena, has plant growth inhibitory activity. FCs have the potential as candidates for a new family of plant hormones as they have been found endogenously in all plant species tested and show growth-regulating activities against the plants. While basic research on FCs is progressing, they are also expected to be applied not only to agrochemicals but also as pharmaceuticals. Derivatization of one of the FCs, 2-azahypoxanthine, and the structure-activity relationship (SAR) studies have clarified its activity as a plant growth promoter. Yet, ICA has not been derivatized at all and SAR regarding its activity remains unknown. In this study we synthesized the derivatives of ICA by direct C--H arylation of ICA precursors and evaluated its activity in rice. The 12 total compounds including the arylated ICAs and their precursors were evaluated for root and shoot elongation in rice, resulting in the discovery that a number of compounds unexpectedly have an elongation activity in the root and shoot. Key words: C--H arylation, fairy chemicals, plant growth activity, imidazole-4-carboxamide, 'Fairy rings' is a phenomenon in which ring-shaped thick growths or necrotic spots of grasses occur. Since the first publication of a scientific paper on fairy rings in 1675, (1) [...]

Stomata-small pores generally found on the leaves of plants-control gas exchange between plant and the atmosphere. Elucidating the mechanism that underlies such control through the regulation of stomatal opening/closing is important to understand how plants regulate photosynthesis and tolerate against drought. However, up-to-date, molecular components and their function involved in stomatal regulation are not fully understood. We challenged such problem through a chemical genetic approach by isolating and characterizing synthetic molecules that influence stomatal movement. Here, we describe that a small chemical collection, prepared during the development of C-H amination reactions, lead to the discovery of a Stomata Influencing Molecule (SIM); namely, a sulfonimidated oxazole that inhibits stomatal opening. The starting molecule SIM1 was initially isolated from screening of compounds that inhibit light induced opening of dayflower stomata. A range of SIM molecules were rapidly accessed using our state-of-the-art C-H amination technologies. This enabled an efficient structure-activity relationship (SAR) study, culminating in the discovery of a sulfonamidated oxazole derivative (SIM*) having higher activity and enhanced specificity against stomatal regulation. Biological assay results have shed some light on the mode of action of SIM molecules within the cell, which may ultimately lead to drought tolerance-conferring agrochemicals through the control of stomatal movement.

This article provides an overview of heteroatom-embedded polycyclic aromatic compounds (hetero-PACs) and their importance in various scientific and technological fields. Hetero-PACs are structurally diverse compounds that contain multiple fused aromatic rings and embedded heteroatoms such as boron, nitrogen, oxygen, phosphorus, and sulfur atoms. They exhibit diverse optoelectronic properties and have applications in organic electronics and chemical biology. The article discusses the stepwise synthesis of hetero-PACs and the challenges associated with it. It then introduces the concept of heteroatom-embedding annulative π-extension (hetero-APEX) reactions as a more efficient synthetic strategy for hetero-PACs. Hetero-APEX reactions allow for the direct construction of fused heteroaromatic structures, offering advantages in terms of step-economy and late-stage tunability. The article concludes by highlighting the potential of hetero-APEX reactions in expanding the structural diversity of hetero-PACs and promoting the discovery of novel heteroaromatics with unique structures, properties, and functions. [Extracted from the article]

This article presents a study on the synthesis of primary benzylamines, which are important in medicinal chemistry. The researchers used a photoredox-catalyzed decarboxylative coupling method with aryl halides and glycine derivatives to create these molecules. They discuss the reaction mechanism and provide experimental results, including different reaction conditions and yields. This research contributes to the development of new synthetic procedures for primary benzylamine scaffolds, which could lead to the discovery of new functional molecules. Additionally, the study explores the decarboxylative aminomethylation of aryl bromides with glycine derivatives, testing various reaction conditions and catalysts to optimize product yield. The researchers found that electron-deficient aryl bromides reacted well, and the reaction was applicable to other heteroarenes. They also investigated the impact of different protecting groups on the nitrogen atom. Overall, this study offers an efficient method for synthesizing aminomethylated compounds, which may have potential applications in drug discovery. [Extracted from the article]

Nanocarbons incorporating non‐hexagonal aromatic rings ‐ such as five‐, seven‐, and eight‐membered rings ‐ have various intriguing physical properties such as curved structures, unique one‐dimensional packing, and promising magnetic, optical, and conductivity properties. Herein, we report an efficient synthetic approach to polycyclic aromatics containing seven‐membered rings via a palladium‐catalyzed intramolecular Ar−H/Ar−Br coupling. In addition to all‐hydrocarbon scaffolds, heteroatom‐embedded heptagon‐containing polyarenes can be efficiently constructed with this method. Rhodium‐ and palladium‐catalyzed sequential six‐ and seven‐membered ring formations also afford complex heptagon‐containing molecular nanocarbons from readily available arylacetylenes and biphenyl boronic acids. Detailed mechanistic analysis by DFT calculations showed the feasibility of seven‐membered ring formation by a concerted metalation‐deprotonation mechanism. This reaction can serve as a template for the synthesis of a wide range of seven‐membered ring‐containing molecular nanocarbons. [ABSTRACT FROM AUTHOR]

Fluorinated cycloparaphenylenes (FCPPs) have attracted attention as electron-accepting CPPs as well as strained fluoroarenes. Herein, we report the synthesis and properties of novel FCPPs; F16[8]CPP and F12[6]CPP. Furthermore, the derivatization of F16[8]CPP afforded a new carbon nanoring where sixteen pyrrole rings are densely substituted on the CPP framework. [ABSTRACT FROM AUTHOR]

Circadian clocks are biological timekeeping systems that coordinate genetic, metabolic and physiological behaviors with the external day–night cycle. The clock in plants relies on the transcriptional-translational feedback loops transcription-translation feedback loop (TTFL), consisting of transcription factors including PSUEDO-RESPONSE REGULATOR (PRR) proteins, plant lineage–specific transcriptional repressors. Here, we report that a novel synthetic small-molecule modulator, 5-(3,4-dichlorophenyl)-1-phenyl-1,7-dihydro-4H-pyrazolo[3,4-d] pyrimidine-4,6(5H)-dione (TU-892), affects the PRR7 protein amount. A clock reporter line of Arabidopsis was screened against the 10,000 small molecules in the Maybridge Hitfinder 10K chemical library. This screening identified TU-892 as a period-lengthening molecule. Gene expression analyses showed that TU-892 treatment upregulates CIRCADIAN CLOCK–ASSOCIATED 1 (CCA1) mRNA expression. TU-892 treatment reduced the amount of PRR7 protein, a transcriptional repressor of CCA1. Other PRR proteins including TIMING OF CAB EXPRESSION 1 were altered less by TU-892 treatment. TU-892-dependent CCA1 upregulation was attenuated in mutants impaired in PRR7. Collectively, TU-892 is a novel type of clock modulator that reduces the levels of PRR7 protein. [ABSTRACT FROM AUTHOR]