18 research outputs found

    Nickel-Catalyzed Negishi-Type Arylation of Trialkylsulfonium Salts

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    Negishi-type arylation of trialkylsulfonium salts with arylzinc reagents has been accomplished under nickel catalysis. The use of cyclohexanethiol as an additional ligand was found to be particularly important to promote C–S cleavage. The present reaction accommodates one-pot arylation of dialkyl sulfides by combining with S-methylation with MeOTf. Mechanistic experiments suggest that C–S cleavage would proceed via single-electron transfer (SET) to generate the most stable carbon-centered radical and that the thiolate ligand would promote the C–S cleavage and radical recombination step

    Palladium-Catalyzed Alkoxycarbonylation of Arylsulfoniums

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    Alkoxycarbonylation of arylsulfoniums has been developed with the aid of a catalytic amount of a palladium-Xantphos complex under an atmospheric pressure of CO gas. Various functional groups such as carbonyl, cyano, halo, and sulfonyl groups were well tolerated under the present catalysis. Since aryldimethylsulfoniums were readily prepared from the corresponding aryl methyl sulfides and methyl triflate, one-pot alkoxycarbonylation of aryl methyl sulfides could be accomplished

    Primary ectopic breast cancer of the vulva, treated with local excision of the vulva and sentinel lymph node biopsy: a case report

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    Abstract Primary breast cancer fairly infrequently occurs in ectopic breast tissue, and primary ectopic breast cancer of the vulva is particularly rare. Only 26 cases have been published in the English-language literature, and there has been no report of primary breast carcinoma of the vulva in Japan. We report a rare case of primary ectopic breast cancer of the vulva that was treated with local excision of the vulva and sentinel lymph node biopsy (SLNB). The patient was a 72-year-old woman who had noticed a right vulvar tumor 10 years earlier. The tumor was excised by the Department of Plastic Surgery of our hospital. The histology of the vulvar tumor revealed an invasive ductal carcinoma of the breast, and immunohistochemical staining of the vulvar specimen showed the tumor cells to be 100% estrogen-receptor-positive and 100% progesterone-receptor-positive. All margins of resection were positive for neoplastic involvement. An additional local excision of the vulva and right inguinal SLNB were performed in our department. The intraoperative frozen section was negative for metastasis, and lymph node dissection was not performed. The final pathology was negative for residual disease, and a partially normal ductal component was present. Adjuvant hormonal therapy with an aromatase inhibitor was indicated post-operatively. The patient was asymptomatic and free of detectable disease at a 6-month follow-up. Due to the rarity of this diagnosis, there are no established guidelines for treatment. Although cases in which SLNB was performed are rare, we consider SLNB to be an effective alternative to inguinal node dissection for ectopic primary breast cancer of the vulva

    Phylogenomics and morphology of extinct Paleognaths reveal the origin and evolution of the ratites

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    The Palaeognathae comprise the flightless ratites and the volant tinamous, and together with the Neognathae constitute the extant members of class Aves. It is commonly believed that Palaeognathae originated in Gondwana since most of the living species are found in the Southern Hemisphere [1–3]. However, this hypothesis has been questioned because the fossil paleognaths are mostly from the Northern Hemisphere in their earliest time (Paleocene) and possessed many putative ancestral characters [4]. Uncertainties regarding the origin and evolution of Palaeognathae stem from the difficulty in estimating their divergence times [1, 2] and their remarkable morphological convergence. Here, we recovered nuclear genome fragments from extinct elephant birds, which enabled us to reconstruct a reliable phylogenomic time tree for the Palaeognathae. Based on the tree, we identified homoplasies in morphological traits of paleognaths and reconstructed their morphology-based phylogeny including fossil species without molecular data. In contrast to the prevailing theories, the fossil paleognaths from the Northern Hemisphere were placed as the basal lineages. Combined with our stable divergence time estimates that enabled a valid argument regarding the correlation with geological events, we propose a new evolutionary scenario that contradicts the traditional view. The ancestral Palaeognathae were volant, as estimated from their molecular evolutionary rates, and originated during the Late Cretaceous in the Northern Hemisphere. They migrated to the Southern Hemisphere and speciated explosively around the Cretaceous-Paleogene boundary. They then extended their distribution to the Gondwana-derived landmasses, such as New Zealand and Madagascar, by overseas dispersal. Gigantism subsequently occurred independently on each landmass.No Full Tex
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