Publications by authors named "Kang-Kang Sun"

Mitochondrial DNA (mtDNA) has been widely used as a valuable tool in studies related to evolution and population genetics, under the implicit assumption of neutral evolution. However, recent studies suggest that natural selection also plays a significant role in shaping mitochondrial genome evolution, although the specific driving forces remain elusive. In this study, we aimed to investigate whether and how climate influences mitochondrial genome evolution by comparing the selection pressures acting on mitochondrial genomes between two rice planthoppers, (Horváth) and (Fallén), which have different climate distributions.

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Article Synopsis
  • The study investigates the genetic structure of the small brown planthopper (L. striatellus) populations from China and Japan to understand its migration patterns.
  • Findings indicate weak genetic differences between the populations, suggesting that L. striatellus migrates from China to both southern and northern Japan, potentially influenced by the East Asian summer monsoon.
  • The research highlights the significance of the X chromosome in tracking species migration and emphasizes the importance of this information for predicting and managing outbreaks of this rice pest.
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The iron-catalyzed α-C-H alkylation of N-methylanilines without any directing group by cross-dehydrogenative coupling between unactivated C(sp)-H and C(sp)-H bonds has been established for the first time, which provides a good complement to C(sp)-H activation reactions and expands the field of Fe-catalyzed C-H functionalizations. Many different C(sp)-H bonds in cyclic alkanes, cyclic ethers, and toluene derivatives can be used as coupling partners. Mechanistic investigations including the radical reaction process, the main role of various reagents, and the kinetic isotope effect experiment were also described.

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A nickel-catalyzed cross-dehydrogenative coupling reaction of α-C(sp)-H bonds in N-methylamides with C(sp)-H bonds from cyclic alkanes has been developed, which offers a cheap transition-metal-catalyzed C-H activation method for amides without the requirement for any extraneous directing group. This new strategy is highly selective and tolerates a variety of functional groups. Mechanistic investigations into the reaction process are also described in detail.

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A cobalt-catalyzed regioselective C-H halogenation methodology is reported herein. The highlight of this work is the highly selective C-H functionalization of anilides, which results in high-yielding, versatile, and practical halogenated products. Thereby, brominations, chlorinations and iodinations of many electron-rich and electron-deficient anilides were achieved in a highly selective fashion.

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β-O-4 and α-O-4 linkages can be selectively cleaved by Pd-Ni bimetallic nanoparticles in ionic liquids using hydrogen gas as the hydrogen donor under ambient pressure and neutral conditions. No hydrogenation of the benzene ring takes place in the catalytic system. An obvious improvement in activity is found compared with single nickel and palladium catalysts based on the results of experiments and characterization.

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