排序方式: 共有11条查询结果,搜索用时 31 毫秒
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Ran Zhao Guidong Feng Xiaodong Xin Honghao Guan Jing Hua Renzhong Wan Wei Li Lei Liu 《中国化学快报》2019,30(7):1432-1434
Current synthesis of α-substituted 3,6-dihydro-2H-pyrans dominantly relies on functional group transformation. Herein, a direct and practical oxidative C-H alkynylation and alkenylation of 3,6-dihydro-2H-pyran skeletons with a range of potassium trifluoroborates is developed. The metal-free process is well tolerated with a wide variety of 3,6-dihydro-2H-pyrans, rapidly providing a library of 2,4-disubstituted 3,6-dihydro-2H-pyrans with diverse patterns of α-functionalities for further diversification and bioactive small molecule identification. 相似文献
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Valentin M. Hertz Michael Bolte Hans‐Wolfram Lerner Matthias Wagner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(30):8924-8928
Herein we show that replacing the two meso carbon atoms of the polycyclic aromatic hydrocarbon (PAH) bisanthene by boron atoms transforms a near‐infrared dye into an efficient blue luminophore. This observation impressively illustrates the impact of boron doping on the frontier orbitals of PAHs. To take full advantage of this tool for the targeted design of organic electronic materials, the underlying structure–property relationships need to be further elucidated. We therefore developed a modular synthesis sequence based on a Peterson olefination, a stilbene‐type photocyclization, and an Si–B exchange reaction to substantially broaden the palette of accessible polycyclic aromatic organoboranes and to permit a direct comparison with their PAH congeners. 相似文献
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The use of organoborane intermediates for radiohalogenations is briefly reviewed. The synthesis of an iodine-123 labeled curcumin derivative using a newly developed radio-iodination technique is reported. 相似文献
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Zhiyu Xie Lei Liu Wenfang Chen Hongbo Zheng Qingqing Xu Huiqing Yuan Hongxiang Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(15):3985-3989
Described is a practical and universal C H functionalization of readily removable N‐benzyl and N‐allyl carbamates, with a wide range of nucleophiles at ambient temperature promoted by Ph3CClO4. The metal‐free reaction has an excellent functional‐group tolerance, and displays a broad scope with respect to both N‐carbamates and nucleophile partners (a variety of organoboranes and C H compounds). The synthetic utility in target‐ as well as diversity‐oriented syntheses is demonstrated. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(1):360-364
BCl3‐induced borylative cyclization of aryl‐alkynes possessing ortho‐EMe (E=S, O) groups represents a simple, metal‐free method for the formation of C3‐borylated benzothiophenes and benzofurans. The dichloro(heteroaryl)borane primary products can be protected to form synthetically ubiquitous pinacol boronate esters or used in situ in Suzuki–Miyaura cross couplings to generate 2,3‐disubstituted heteroarenes from simple alkyne precursors in one pot. In a number of cases alkyne trans‐haloboration occurs alongside, or instead of, borylative cyclization and the factors controlling the reaction outcome are determined. 相似文献
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Two new pentacyclic alkaloids, mersiphyllines A (1) and B (2), belonging to the novel mersinine group, and incorporating carboxylic acid functionalities on a quaternary center, were isolated from Kopsia singapurensis. The structures were determined by spectroscopic analysis. Determination of the relative configuration at the quaternary center bearing the acid function was facilitated by the formation of an alkaloid-borane complex. The structure of 1 was also confirmed by X-ray diffraction analysis. 相似文献