3 research outputs found

    Leprarioid lichens and associated lichenicolous fungi from the Commander Islands (Kamchatka Territory, Russia) including a new species Lepraria tiinae

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    Here, we present new records of leprarioid lichens from the Commander Islands, including one species of Lithocalla and six species of Lepraria. Notably, we describe as new to science Lepraria tiinae, which is quite common in coastal biotopes of the archipelago. The main distinguishing phenotypic features of this new species include large granules of the thallus, a well-developed hypothallus, dark rhizohyphae, and the production of thiophanic acid, arthothelin, and dichlorolichexanthone. Additionally, three species of lichenicolous fungi or fungi associated with leprarioid lichens were found in the studied specimens, all of which are new to the Kamchatka Territory

    Reaction for the Synthesis of Benzimidazol-2-ones, Imidazo[5,4‑<i>b</i>]‑, and Imidazo[4,5‑<i>c</i>]pyridin-2-ones via the Rearrangement of Quinoxalin-2-ones and Their Aza Analogues When Exposed to Enamines

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    A synthetically useful protocol has been developed for the preparation of highly functionalized <i>N</i>-pyrrolylbenzimidazol-2-ones. The reaction of variously substituted 3-aroyl- and 3-alkanoylquinoxalin-2­(1<i>H</i>)-ones with commercially available enamines in acetic acid results in a rapid rearrangement and formation of <i>N</i>-pyrrolylbenzimidazol-2-ones in modest to excellent yields. The key step of the rearrangement involves the novel ring contraction of 3-aroyl- and 3-alkanoylquinoxalin-2­(1<i>H</i>)-ones with enamines. In this case, the atom of carbon which is displaced from the pyrazine ring of quinoxalin-2­(1<i>H</i>)-one becomes the fourth carbon atom of the newly formed pyrrole ring. The method is applicable for the aza analogues of quinoxalin-2­(1<i>H</i>)-ones

    Rearrangement of Quinoxalin-2-ones When Exposed to Enamines Generated in Situ from Ketones and Ammonium Acetate: Method for the Synthesis of 1‑(Pyrrolyl)benzimidazolones

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    The reaction of 3-benzoylquinoxalin-2­(1<i>H</i>)-ones with enamines (generated in situ from ammonium acetate and the corresponding methylaryl­(hetaryl)­ketones) proceeds smoothly to give the corresponding substituted 1-(pyrrolyl)­benzimidazolone derivatives in moderate yields through the novel rearrangement of 3-benzoylquinoxalin-2­(1<i>H</i>)-ones involving a dual cleavage of the C3N4 and C2-C3 bonds under mild conditions
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