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可见光氧化还原钴催化立体发散性合成1,4-二烯
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作者 任行宇 刘佳俊 +5 位作者 张士启 李彦霖 崔坤 李静 顾正洋 夏纪宝 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第6期291-300,共10页
1,4-二烯是一类重要的烯烃化合物,其分子骨架广泛存在于药物和天然产物中.由于1,4-二烯分子在有机合成中具有重要作用,目前其合成方法已被广泛研究,包括1,3-二烯的氢烯基化、炔烃的氢烯丙基化、乙烯基和烯丙基试剂的交叉偶联等.然而,由... 1,4-二烯是一类重要的烯烃化合物,其分子骨架广泛存在于药物和天然产物中.由于1,4-二烯分子在有机合成中具有重要作用,目前其合成方法已被广泛研究,包括1,3-二烯的氢烯基化、炔烃的氢烯丙基化、乙烯基和烯丙基试剂的交叉偶联等.然而,由于1,4-二烯的热力学稳定性,现有的合成方法主要倾向于生成E-立体选择性的产物,而Z-异构体的生成则相对困难.值得注意的是,通过同一组底物同时构建1,4-二烯的Z和E异构体的立体发散性合成策略鲜有报道.因此,发展新型催化体系,以同时构建1,4-二烯的Z和E异构体具有十分重要的意义和应用前景.本文报道了一种高效的可见光光致氧化还原/钴协同催化策略,该策略以联烯与炔烃为原料,通过调控反应溶剂即可实现立体发散性地构建Z,E-和E,E-1,4-二烯化合物.该反应在室温下,以2,4,5,6-四(9-咔唑基)-间苯二腈(4CzIPN)作为光敏剂,4,6-双(二苯基膦基)-10H-吩噁嗪为配体,H_(2)O和DIPEA作为氢源,实现了1,4-二烯的高效合成.值得一提的是,通过简单地调控溶剂可以直接控制产物的立体选择性,即以乙腈为溶剂时可得到Z,E-1,4-二烯产物,而使用2-MeTHF作为溶剂时,则得到E,E-1,4-二烯产物.此外,该反应对炔烃底物具有良好的兼容性,包括乙基、硅醚、羟基和环丙基等非对称的芳基烷基内炔,均能与联烯有效偶联,以较高收率得到目标产物.此外,芳基上带有各种富电子和缺电子基团的炔烃也能很好地参与反应.联烯底物研究结果表明,联烯上的酯基对反应效率有显著影响,具有较小酯取代基的联烯,如甲基和乙基,反应活性较低,相应的产物收率较低;而具有较大酯基的联烯,如异丙基、苄基和叔丁基,则能获得更高的产率.此外,当使用苯基、酸酐、二苯基氧化膦或磺酰基等其他官能团取代的联烯时,反应无法发生.通过氘代实验、荧光猝灭实验等一系列控制实验以及密度泛函理论计算,揭示了该反应机制.反应过程涉及五元钴环戊烯中间体的分解,并通过光催化的能量转移过程实现了E,E-1,4-二烯的E→Z异构化,最终实现Z,E-1,4-二烯的立体选择性合成.综上所述,本文提出了一种新的钴催化炔烃-联烯的选择性还原偶联反应.通过结合可见光光致氧化还原与钴协同催化策略,在温和的条件下,以H_(2)O和DIPEA作为氢源,实现了具有良好区域选择性和立体选择性的Z,E-和E,E-1,4-二烯的立体发散性合成.通过控制反应溶剂来实现立体选择性,本研究为立体发散性合成1,4-二烯化合物提供了一种简单有效的新途径. 展开更多
关键词 1 4-二烯 钴催化 光氧化还原 还原偶联 炔烃 联烯
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Sarcomatoid intrahepatic cholangiocarcinoma mimicking liver abscess: A case report 被引量:7
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作者 Yan Wang Jia-Lei Ming +4 位作者 xing-yu ren Lu Qiu Li-Juan Zhou Shu-Dong Yang Xiang-Ming Fang 《World Journal of Clinical Cases》 SCIE 2020年第1期208-216,共9页
BACKGROUND Sarcomatoid intrahepatic cholangiocarcinoma(SICC) is an extremely rare and highly invasive malignant tumor of the liver. To our knowledge, the imaging findings of sarcomatous cholangiocarcinoma have been ra... BACKGROUND Sarcomatoid intrahepatic cholangiocarcinoma(SICC) is an extremely rare and highly invasive malignant tumor of the liver. To our knowledge, the imaging findings of sarcomatous cholangiocarcinoma have been rarely reported; and radiological features of this tumor mimicking liver abscess have not yet been reported.CASE SUMMARY We present a case of SICC mimicking liver abscess. The patient, a 43-year-old male, complained of repeated upper right abdominal discomfort and intermittent distension over a period of one month. Radiology examination revealed a huge focal lesion in the right liver. The lesion was hypointense on computed tomography with honeycomb enhancement surrounded by enhanced peripheral areas. It showed a hypo-signal on non-contrast T1-weighted images and a hypersignal on non-contrast T2-weighted images. Radiologists diagnosed the lesion as an atypical liver abscess. The patient underwent a hepatectomy. After surgery, he survived another 2.5 mo before passing away. A search of Pub Med and Google revealed 43 non-repeated cases of SICC reported in 20 published studies. The following is a short review in order to improve the diagnostic and therapeutic skills in cases of SICC.CONCLUSION This report presents the clinical and radiological features of SICC and imaging features which showed hypovascularity and progressive enhancement. SICC can present as a multilocular cyst on radiological images and it is necessary to distinguish this lesion from an atypical abscess. Simple surgical treatment is not the best treatment option for this disease. 展开更多
关键词 Sarcomatoid intrahepatic cholangiocarcinoma Liver abscess Radiological features Case report
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Single-lung transplantation for pulmonary alveolar microlithiasis: A case report
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作者 xing-yu ren Xiang-Ming Fang +6 位作者 Jing-Yu Chen Hao Ding Yan Wang Qiu Lu Jia-Lei Ming Li-Juan Zhou Hong-Wei Chen 《World Journal of Clinical Cases》 SCIE 2019年第22期3851-3858,共8页
BACKGROUND Pulmonary alveolar microlithiasis(PAM)is a rare idiopathic lung disease characterized by the accumulation of innumerable microliths.Currently,effective therapeutics for PAM are not available,and the only tr... BACKGROUND Pulmonary alveolar microlithiasis(PAM)is a rare idiopathic lung disease characterized by the accumulation of innumerable microliths.Currently,effective therapeutics for PAM are not available,and the only treatment for end-stage lung disease is lung transplantation(LuTx).Further,there are few reports that focus on LuTx for the treatment of PAM,and the follow-up reports of postoperative imaging are even rarer.CASE SUMMARY A 52-year-old man presented to Shanghai Pulmonary Hospital in 2017 after experiencing shortness of breath and exacerbation.The patient was diagnosed with PAM and referred for single-LuTx(SLuTx)on March 14,2018.Preoperative imaging results from a chest X-ray demonstrated bilateral,diffuse,symmetrical,sandstorm-like radiopaque micronodules,and pneumothorax and a computed tomography scan revealed minute,calcified military nodules in both lungs.We performed a left SLuTx,and intraoperative pathology was consistent with PAM.One week after surgery,a chest X-ray revealed slight exudation of the left lung,and one month later,the left transplanted lung exhibited good dilation,mild pulmonary perfusion injury with local infection,and left pleural effusion.Fiberoptic bronchoscopy revealed left hyperplastic granulation at the left bronchial anastomosis.Multiple sputum cultures suggested the presence of Klebsiella pneumoniae and Acinetobacter baumannii.The last follow-up was conducted in April 2019;the patient recovered well.CONCLUSION This case presents the imaging findings of a patient with PAM before and after LuTx and confirms the effectiveness of LuTx for the treatment of this disease. 展开更多
关键词 Pulmonary ALVEOLAR MICROLITHIASIS Lung TRANSPLANTATION COMPLICATIONS CHEST X-ray COMPUTED tomography Case report
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