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Dr. Aurélien Tap Camille Lecourt Sabrina Dhambri Mathieu Arnould Dr. Gilles Galvani Dr. Olivier Nguyen Van Buu Dr. Morgan Jouanneau Dr. Jean‐Pierre Férézou Prof. Janick Ardisson Dr. Marie‐Isabelle Lannou Dr. Geoffroy Sorin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4938-4944
The development of an intramolecular rhodium(I)‐catalyzed Pauson–Khand reaction of alkoxyallene‐ynes with a proximal alkoxy group is reported. This reaction, in the presence of a [Rh(cycloocta‐1,5‐diene)Cl]2/propane‐1,3‐diylbis(diphenylphosphane) system under a CO atmosphere, constitutes a powerful tool for selectively accessing carbo‐ and heterobicyclo[5.3.0] frameworks featuring an enol ether moiety. Through this procedure, a straightforward access to guaiane skeletons with a tertiary hydroxy group at the C10 position was achieved. 相似文献
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Dr. Sébastien Thiery Dr. Denis Tondelier Bernard Geffroy Dr. Olivier Jeannin Dr. Joëlle Rault‐Berthelot Dr. Cyril Poriel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10136-10149
This work reports a detailed structure–property relationship study of a series of efficient host materials based on the donor–spiro–acceptor (D‐spiro‐A) design for green and sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs). The electronic and physical effects of the indoloacridine (IA) fragment connected through a spiro bridge to different acceptor units, namely, fluorene, dioxothioxanthene or diazafluorene moiety, have been investigated in depth. The resulting host materials have been easily synthesised through short, efficient, low‐cost, and highly adaptable synthetic routes by using common intermediates. The dyes possess a very high triplet energy (ET) and tuneable HOMO/LUMO levels, depending on the strength of the donor/acceptor combination. The peculiar electrochemical and optical properties of the IA moiety have been investigated though a fine comparison with their phenylacridine counterparts to study the influence of planarisation. Finally, these molecules have been incorporated as hosts in green and sky‐blue PhOLEDs. For the derivative SIA‐TXO2 as a host, external quantum efficiencies as high as 23 and 14 % have been obtained for green and sky‐blue PhOLEDs, respectively. 相似文献
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The [2.2.2]hericene ( 6 ), a bicyclo[2.2.2]octane bearing three exocyclic s-cis-butadiene units has been prepared in eight steps from coumalic acid and maleic anhydride. The hexaene 6 adds successively three mol-equiv. of strong dienophiles such as ethylenetetracarbonitrile (TCE) and dimethyl acetylenedicarboxylate (DMAD) giving the corresponding monoadducts 17 and 20 (k1), bis-adducts 18 and 21 (k2) and tris-adducts 19 and 22 (k3), respectively. The rate constant ratio k1/k2 is small as in the case of the cycloadditions of 2,3,5,6-tetramethylidene-bicyclo [2.2.2]octane ( 3 ) giving the corresponding monoadducts 23 and 27 (k1) and bis-adducts 25 and 29 (k2) with TCE and DMAD, respectively. Constrastingly, the rate constant ratio k2/k3 is relatively large as the rate constant ratio k1/k2 of the Diels-Alder additions for 5,6,7,8-tetramethylidenebicyclo [2.2.2]oct-2-ene ( 4 ) giving the corresponding monoadducts 24 and 28 (k1) and bis-adducts 26 and 30 (k2). The following second-order rate constants (toluene, 25°) and activation parameters were obtained for the TCE additions: 3 +TCE→ 23 : k1 = 0.591±0.012 mol?1·l·s?1, ΔH≠=10.6±0.4 kcal/mol, and ΔS≠ = ?24.0±1.4 cal/mol·K (e.u.); 23 +TCE→ 25 : k2=0.034±0.0010 mol?1·l·s?1, ΔH≠ = 10.6±0.6 kcal/mol, and ΔS≠ = ?29.7±2.0 e.u.; 4 +TCE→ 26 : k1 = 0.172±0.035 mol?1·l·s?1, ΔH≠ 11.3±0.8 kcal/mol, and ΔS≠ = ?24.0±2.8 e.u.; 24 +TCE→ 26 : k2 = (6.1±0.2)·10?4 mol?1·l·s?1, ΔH≠ = 13.0±0.3 kcal/mol, and ΔS≠ = ?29.5±0.8 e.u.; 6 +TCE→ 17 : k1 = 0.136±0.002 mol?1·l·s?1, ΔH≠ = 11.3±0.2 kcal/mol, and ΔS≠ = ?24.5±0.8 e.u.; 17 +TCE→ 18 : k2 = 0.0156±0.0003 mol?1·l·s?1, ΔH≠ = 10.9±0.5 kcal/mol, and ΔS≠ = ?30.1 ± 1.5 e.u.; 18 +TCE→ 19 : k3=(5±0.2) · 10?5 mol?1 mol?1 ·l·s?1, ΔH≠ = 15±3 kcal/mol, and ΔS≠ = ?28 ± 8 e.u. The following rate constants were evaluated for the DMAD additions (CD2Cl2, 30°): 6 +DMAD→ 20 : k1 = (10±1)·10?4 mol?1 · l·s?1; 20 +DMAD→ 21 : k2 = (6.5±0.1) · 10?4 mol?1 ·l·?1; 21 +DMAD→ 22 : k3 = (1.0±0.1) · 10?4 mol?1 ·l·s?1. The reactions giving the barrelene derivatives 19, 22, 26 and 30 are slower than those leading to adducts that are not barrelenes. The former are estimated less exothermic than the latter. It is proposed that the Diels-Alder reactivity of exocyclic s-cis-butadienes grafted onto bicycle [2.2.1]heptanes and bicyclo [2.2.2]octanes that are modified by remote substitution of the bicyclic skeletons can be affected by changes inthe exothermicity of the cycloadditions, in agreement with the Dimroth and Bell-Evans-Polanyi principle. Force-field calculations (MMPI 1) of 3, 4, 6 and related exocyclic s-cis-butadienes as a moiety of bicyclo [2.2.2]octane suggested single minimum energy hypersurfaces for these systems (eclipsed conformations, planar dienes). Their flexibility decreases with the degree of unsaturation of the bicyclic skeleton. The effect of an endocyclic double bond is larger than that of an exocyclic diene moiety. 相似文献