排序方式: 共有29条查询结果,搜索用时 31 毫秒
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Dr. Hikaru Yanai Teru Kawazoe Nobuyuki Ishii Prof. Dr. Bernhard Witulski Prof. Dr. Takashi Matsumoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(44):11442-11449
4-Aryl-1,3-dihydroxy-2-naphthoates having the less accessible 1,2,3,4-tetrasubstituted naphthalene scaffold and that show photoluminescence emission from solid state as well as in solutions, were selectively synthesized from brominated lactol silyl ethers through the 1,2-aryl-migrative ring rearrangement reaction. 相似文献
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Gerald Frber Walter Keller Christoph Kratky Berhard Jaun Andreas Pfaltz Christoh Spinner Andr Kobelt Albert Eschenmoser 《Helvetica chimica acta》1991,74(4):697-716
The structure of a derivative of coenzyme F430 from methanogenic bacteria, the bromide salt of 12,13-diepi-F430 pentamethyl ester ( 5 , X = Br), was determined by X-ray structure analysis. It reveals a more pronounced saddle-shaped out-of-plane deformation of the macrocycle than any hydroporphinoid Ni complex investigated so far. The crystal structure confirms the constitution proposed for coenzyme F430 ( 2 ) and shows that in the epimer 5 , the three stereogenic centers in ring D, C(17), C(18), and C(19), have the (17S)-, (18S)-, and (19R)-configuration, respectively. Deuteration and 2D-NMR studies independently demonstrate that native coenzyme F430 (2) has the same configuration in ring D as the epimer 5 . Therefore, our original tentative assignment of configuration at C(19) and C(18) [1] has to be reversed. This completes the assignment of configuration for all stereogenic centers in coenzyme F430, which has the structure shown in Formula 2 . 相似文献
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Witulski B Weber M Bergsträsser U Desvergne JP Bassani DM Bouas-Laurent H 《Organic letters》2001,3(10):1467-1470
[structure: see text] A novel alkali cation selective probe is described which exhibits unique ICT and binding properties, allowing the ratiometric titration of sodium cations in the presence of other alkali metal ions. 相似文献
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Nissen F Richard V Alayrac C Witulski B 《Chemical communications (Cambridge, England)》2011,47(23):6656-6658
A flexible approach towards substituted β- and γ-carbolines based on transition metal catalysed [2+2+2] cycloaddition reactions between functionalised yne-ynamides and methylcyanoformate is described. The versatility of this new reaction sequence is demonstrated by its application in the total synthesis of the marine natural product eudistomin U. 相似文献