Synthesis of Perfluoroalkyl-Substituted<i>γ</i>-Lactones and 4,5-Dihydropyridazin-3(2<i>H</i>)-ones<i>via</i>DonorAcceptor Cyclopropanes
作者:Daniel Gladow、Hans-Ulrich Reissig
DOI:10.1002/hlca.201200413
日期:2012.10
presence of perfluoroalkyl‐ or perfluoroaryl‐substituted silyl enol ethers smoothly provided the corresponding alkyl 2‐siloxycyclopropanecarboxylates in very good yields. The generated donoracceptor cyclopropanes are equivalents of γ‐oxo esters, which we demonstrated by their one‐pot transformations to yield fluorine‐containing heterocycles. A reductive procedure selectively afforded perfluoroalkyl‐substituted
Discovery of a Negative Allosteric Modulator of GABA<sub>B</sub> Receptors
作者:Lin-Hai Chen、Bing Sun、Yang Zhang、Tong-Jie Xu、Zhi-Xiong Xia、Jian-Feng Liu、Fa-Jun Nan
DOI:10.1021/ml500162z
日期:2014.7.10
Initialized from the scaffold of CGP7930, an allosteric agonist of GABA(B) receptors, a series of non-competitive antagonists were discovered. Among these compounds, compounds 3, 6, and 14 decreased agonist GABA-induced maximal effect of IP3 production in HEK293 cells overexpressing GABA(B) receptors and Gq(j9) proteins without changing the EC50. Compounds 3, 6, and 14 not only inhibited agonist baclofen-induced ERK1/2 phosphorylation but also blocked CGP7930-induced ERK1/2 phosphorylation in HEK293 cells overexpressing GABA(B) receptors. The results suggested that compounds 3, 6, and 14 are negative allosteric modulators of GABA(B) receptors. The representative compound 14 decreased GABA-induced IP3 production with IC50 of 37.9 mu M and had no effect on other GPCR Class C members such as mGluR1, mGluR2, and mGluRS. Finally, we showed that compound 14 did not bind to the orthosteric binding sites of GABA(B) receptors, demonstrating that compound 14 negatively modulated GABA(B) receptors activity as a negative allosteric modulator.
The Influence of Perfluorinated Substituents on the Nucleophilic Reactivities of Silyl Enol Ethers
作者:Hans A. Laub、Daniel Gladow、Hans-Ulrich Reissig、Herbert Mayr
DOI:10.1021/ol301766w
日期:2012.8.3
The fluorinated trimethylsilyl enol ethers 3a–c were synthesized, and the kinetics of their reactions with the benzhydrylium ions 4 was studied by UV–vis spectroscopy in dichloromethane. Comparison with nonfluorinated analogues shows that replacement of CH3 by CF3 reduces the nucleophilic reactivity by 8 orders of magnitude, while the exchange of C6H5 by C6F5 retards the reactions by 4.5 orders of
合成了氟化的三甲基甲硅烷基烯醇醚3a – c,并通过在二氯甲烷中的紫外-可见光谱研究了它们与苯甲基铵离子4的反应动力学。与非氟化类似物的比较表明,用CF 3取代CH 3可使亲核反应性降低8个数量级,而用C 6 F 5交换C 6 H 5则使反应延迟4.5个数量级。