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When a mixture containing 1‐halo‐1‐alkyne, a dinucleophilic agent, and a base (Cs2CO3 or K3PO4) was heated in DMF, regio‐ and stereo‐selective nucleophilic addition of the dinucleophilic agent to the acetylenes occurred. This reaction yielded (Z,Z)‐bis(haloalkene), which subsequently underwent Pd‐catalyzed cyclization through C−H bond activation, resulting in the formation of two‐oxygen‐ or ‐nitrogen‐containing hetero‐π‐conjugated compounds. N‐(5‐Hydroxynaphthalen‐1‐yl)methanesulfonamide was treated with 2‐phenyl‐1‐chloroethyne followed by 1‐chloro‐1‐hexadecyne. After these reactions, Pd‐catalyzed double C−H cyclization was employed to produce 1H‐2‐phenyl‐7‐tetradecylbenzofuro[7,6‐g]indole. Notably, this compound transformed into a fan‐shaped structure at 86 °C and transitioned into a smectic A phase characterized by a layered structure. [ABSTRACT FROM AUTHOR]

Hatchery fish and their offspring (including hatchery‐wild hybrids) have lower reproductive success than wild fish. Thus, the straying of hatchery fish may negatively impact wild populations, depending on the number of wild salmon returning and hatchery strays. We investigated the straying status of hatchery‐origin pink salmon (Oncorhynchus gorbuscha), which have a higher straying rate than other salmonids, in an unstocked river at the Shiretoko World Natural Heritage Site, Japan. The hatchery strays accounted for 40.0% and 19.0% of the total samples in 2021 and 2022, respectively. These results indicate that hatchery pink salmon have invaded unstocked rivers and potentially genetically affect wild populations. [ABSTRACT FROM AUTHOR]

Increased flood magnitude and frequency due to climate change can reduce the population productivity of organisms such as amphibian and fish species in river and stream systems; therefore, conserving habitats that maintain high productivity under such conditions is crucial. Here, we examined the relationship between the freshwater productivity of anadromous salmonids (measured as fry migrating to the ocean per spawner) and catchment hydrogeomorphology and identified the characteristics of rivers and streams that are prone to flood disturbance.We surveyed the spawner abundance and number of fry of pink salmon (Oncorhynchus gorbuscha) and measured environmental factors, including the average catchment slope and stream power, as characteristics of hydrogeomorphology, in 10 streams in the Shiretoko Peninsula, northern Japan. We then used generalised linear mixed models to predict the freshwater productivity of pink salmon populations in each catchment across the study region under current and future climatic conditions.The productivity of pink salmon in the study region differed among the sampled catchments and was negatively affected by the average catchment slope, stream power, and maximum daily precipitation averaged over the catchment. Namely, flood disturbance reduced the freshwater productivity of pink salmon, and salmon productivity in individual catchments was explained by catchment hydrogeomorphology. The predicted future productivity with increased precipitation was also lower than the current productivity.Our approach can be applied to other salmonids that have similar spawning behaviour to pink salmon. Highly productive catchments under the future climatic conditions predicted by the present study should be prioritised for conservation to ensure a sustainable salmonid population. [ABSTRACT FROM AUTHOR]

Titanated pyridines in highly selective manner were produced directly by the four-component process that involves two acetylenes, a nitrile, and a divalent titanium alkoxide reagent, Ti(O-i-Pr)(sub 4)/2i-PrMgCl. Synthetic application of this process is illustrated in the preparation of optically active pyridines and medically useful compounds.

Downstream migration is a critical stage in the anadromous salmonid life cycle, but previous studies have shown different results between rivers or surveys for the diel downstream migration pattern of the fry of the pink salmon Oncorhynchus gorbuscha. We investigated the diel migration pattern of pink salmon fry in three small streams. Our results showed that pink salmon fry migrate mainly within a few hours after sunset; 89.9% of migration occurred between 18:00 and 23:00. Therefore, the results indicated that sunset time influences the diel migration pattern of pink salmon fry in small streams. This pattern could be a predator‐avoidance behaviour. [ABSTRACT FROM AUTHOR]

2-Aryl-3-(sulfonyl)-5,6-dihydro-2H-pyran is produced when arylmethyl 4-(sulfonyl)-3-butynyl ether and a catalytic amount of [Rh.sub.2][(tfs).sub.4] (tfa = C[F.sub.3]C[O.sub.2.sup.-]) are heated. 2-(5-Sulfonyl-4-pentynyl)tetrahydrofuran lacking a benzyl substituent has produced a different product, 9-sulfonyl-1-hydroxy-8-nonen-4-one, upon reaction with the same rhodium catalyst at reflux in wet toluene.

An yttrium reagent has reacted with a metalated alkene such as a vinyl Gringnard reagent, which has led to the new method of producing 1,2-dimetalated ethane. This reagent has new characteristics that are complementary to those of the existing 1,2-dimetalated ethanes, which are already used in organic synthesis.

The simple method to synthesize 1,4-diaza(or partially oxa)-2-cycloalkenes based on a new copper-catalyzed double amination of haloacetylene is reported. The procedure can be applied to obtain unsaturated heterocyclic compounds having two heteroatoms.

A Grignard addition to olefins uses the radical species generated by the aerial oxidation of Grignard reagents, and enables a one-pot, three-component coupling process of a Grignard reagent, olefin and oxygen in air, to directly yield alcohol. The reaction provides a very simple process free of additional or toxic reagents and no transition metal salts or organotin.