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141.
El Maatougui A Azuaje J Coelho A Cano E Yañez M López C Yaziji V Carbajales C Sotelo E 《Combinatorial chemistry & high throughput screening》2012,15(7):551-554
We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone. 相似文献
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Jullien J Juhász G Mialane P Dumas E Mayer CR Marrot J Rivière E Bominaar EL Münck E Sécheresse F 《Inorganic chemistry》2006,45(17):6922-6927
The synthesis of the first singly bridged non-heme diiron complex with a mu-hydroxo bridging ligand, [{(salten)Fe}2(OH)][B(C6H5)4].(CH3CN)x.(H2O)y (1) [H2salten = 4-azaheptane-1,7-bis(salicylideneiminate)], is reported. The complex has been characterized with X-ray crystallography, FTIR, magnetic susceptibility measurements, and M?ssbauer spectroscopy. The data have been compared with the results of DFT calculations on both 1 and a model with an unsupported mu-oxo bridge (2) to verify the formulation of the complex as a mu-hydroxo-bridged species. The X-ray structure [Fe-O(H) = 1.997(1) A and Fe-O(H)-Fe = 159 degrees ] is consistent with the DFT-optimized geometry of 1 [Fe-O(H) = 2.02 A and Fe-O(H)-Fe = 151 degrees ]; the Fe-O(H) distance in 1 is about 0.2 A longer than the Fe-O separations in the optimized geometry of 2 (1.84 A) and in the crystallographic structures of diiron(III) compounds with unsupported mu-oxo bridges (1.77-1.81 A). The formulation of 1 as a hydroxo-bridged compound is also supported by the presence of an O-H stretch band in the FTIR spectrum of the complex. The magnetic susceptibility measurements of 1 reveal antiferromagnetic exchange (J = 42 cm(-1) and H(ex) = JS(1).S(2)). Nearly the same J value is obtained by analyzing the temperature dependence of the M?ssbauer spectra (J = 43 cm(-1); other parameters: delta = 0.49 mm s(-1), DeltaE(Q) = -0.97 mm s(-1), and eta = 0.45 at 4.2 K). The experimental J values and M?ssbauer parameters agree very well with those obtained from DFT calculations for the mu-hydroxo-bridged compound (J = 46 cm(-1), delta = 0.48 mm s(-1), DeltaE(Q) = -1.09 mm s(-1), and eta = 0.35). The exchange coupling constant in 1 is distinctly different from the value J approximately 200 cm(-1) calculated for the optimized mu-oxo-bridged species, 2. The increased exchange-coupling in 2 arises primarily from a decrease in the Fe-O bond length. 相似文献
144.
A simple approach for the formation of optically active highly functionalized tetrahydrothiophenes, which might find important use in biochemistry, pharmaceutical science, and nanoscience is presented. Development of new organocatalytic Michael-aldol domino reactions is outlined, and with the appropriate choice of additives it is possible to control the regioselectivity of these domino reactions, yielding diastereomerically pure (tetrahydrothiophen-2-yl)phenyl methanones or tetrahydrothiophene carbaldehydes in good yields and with excellent enantioselectivities up to 96% ee. The stereochemical outcome of these reactions is investigated, and the mechanism of these organocatalytic domino processes is presented. 相似文献
145.
This paper describes the controlled self-selection and quantitative parallel amplification of the homonuclear grid architectures derived from the same ligand 1 of different conformational geometries and Cu+ and Ag+ metal ions of different coordination behavior and ionic size. 相似文献
146.
Ohne Zusammenfassung 相似文献
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149.
Hysteretic Spin Crossover above Room Temperature and Magnetic Coupling in Trinuclear Transition‐Metal Complexes with Anionic 1,2,4‐Triazole Ligands 下载免费PDF全文
Dr. Verónica Gómez Dr. Jordi Benet‐Buchholz Dr. Eddy Martin Dr. J. R. Galán‐Mascarós 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(18):5369-5379
The reaction of 4‐(1,2,4‐triazol‐4‐yl)ethanesulfonate ( L ) with Zn2+, Cu2+, Ni2+, Co2+, and Fe2+ gave a series of analogous neutral trinuclear complexes with the formula [M3(μ‐ L )6(H2O)6] ( 1 – 5 ). These compounds were characterized by single‐crystal X‐ray diffraction, thermogravimetry, and elemental analysis. The magnetic properties of compounds 2 – 5 were studied. Complexes 2 – 4 show weak antiferromagnetic superexchange, with J values of ?0.33 ( 2 ), ?9.56 ( 3 ), and ?4.50 cm?1 ( 4 ) (exchange Hamiltonian H=?2 J (S1S2+S2S3)). Compound 5 shows two additional crystallographic phases ( 5 b and 5 c ) that can be obtained by dehydration and/or thermal treatment. These three phases exhibit distinct magnetic behavior. The Fe2+ centers in 5 are in high‐spin (HS) configuration at room temperature, with the central one exhibiting a non‐cooperative gradual spin transition below 250 K with T1/2=150 K. In 5 b , the central Fe2+ stays in its low‐spin (LS) state at room temperature, and cooperative spin transition occurs at higher temperatures and with the appearance of memory effect (T1/2↑=357 K and T1/2↓=343 K). In the case of 5 c , all iron centers remain in their HS configuration down to very low temperatures, with weak antiferromagnetic coupling (J=?1.16 cm?1). Compound 5 b exhibits spin transition with memory effect at the highest temperature reported, which matches the remarkable features of coordination polymers. 相似文献
150.
An Alternative to the Classical α‐Arylation: The Transfer of an Intact 2‐Iodoaryl from ArI(O2CCF3)2 下载免费PDF全文
Dr. Zhiyu Jia Dr. Erik Gálvez Prof. Dr. Rosa María Sebastián Prof. Dr. Roser Pleixats Dr. Ángel Álvarez‐Larena Dr. Eddy Martin Prof. Dr. Adelina Vallribera Dr. Alexandr Shafir 《Angewandte Chemie (International ed. in English)》2014,53(42):11298-11301
The α‐arylation of carbonyl compounds is generally accomplished under basic conditions, both under metal catalysis and via aryl transfer from the diaryl λ3‐iodanes. Here, we describe an alternative metal‐free α‐arylation using ArI(O2CCF3)2 as the source of a 2‐iodoaryl group. The reaction is applicable to activated ketones, such as α‐cyanoketones, and works with substituted aryliodanes. This formal C? H functionalization reaction is thought to proceed through a [3,3] rearrangement of an iodonium enolate. The final α‐(2‐iodoaryl)ketones are versatile synthetic building blocks. 相似文献