93560-55-5Relevant articles and documents
Solid-state fluorescence of zwitterionic imidazolium pyridinolates bearing long alkyl chains: Control of emission properties based on variation of lamellar alignment
Yoshida, Atsushi,Ikeshita, Masahiro,Komiya, Naruyoshi,Naota, Takeshi
, p. 6000 - 6007 (2017/09/18)
Herein, the control of the crystalline-state fluorescence of zwitterionic imidazolium 2-pyridin-3-olate 1 bearing linear alkyl chains via morphological variations is described, along with a mechanistic rationale. Crystals of 1a–e prepared from CH3CN exhibited intense blue fluorescence under UV irradiation at 298 K, whereas crystals of 1e prepared from i-PrOH/Et2O were less emissive under the same measurement conditions. Temperature-dependent emission spectra showed that emissive crystals of 1a–e experienced minimal emission decay with increasing temperature, whereas crystalline 1e, having a different polymorphism, was highly heat-quenchable. Single-crystal XRD established that less emissive, heat-quenchable crystal 1e had a lamellar structure supported by consecutive face-to-face arrangement with π-stacking interactions between imidazolium and pyridinolate moieties, whereas highly emissive, heat-resistant crystals 1d and 1e had a face-to-edge lamellar structure with CH-π interactions between the heteroaromatic rings.
Deprotometalation of substituted pyridines and regioselectivity-computed CH acidity relationships
Hedidi, Madani,Bentabed-Ababsa, Ghenia,Derdour, A?cha,Halauko, Yury S.,Ivashkevich, Oleg A.,Matulis, Vadim E.,Chevallier, Floris,Roisnel, Thierry,Dorcet, Vincent,Mongin, Florence
, p. 2196 - 2205 (2016/04/09)
A series of methoxy- and fluoro-pyridines have been deprotometalated in tetrahydrofuran at room temperature by using a mixed lithium-zinc combination obtained from ZnCl2·TMEDA (TMEDA=N,N,N′,N′-tetramethylethylenediamine) and LiTMP (TMP=2,2,6,6-tetramethylpiperidino) in a 1:3 ratio, and the metalated species intercepted by iodine. Efficient functionalization at the 3 position was observed from 4-methoxy, 2-methoxy, 2,6-dimethoxy, 2-fluoro and 2,6-difluoropyridine, and at the 4 position from 3-methoxy and 2,3-dimethoxypyridine. Interestingly, clean dideprotonation was noted from 3-fluoropyridine (at C2 and C4) and 2,6-difluoropyridine (at C3 and C5). The obtained regioselectivities have been discussed in light of the CH acidities of the substrates, determined both in the gas phase (DFT B3LYP and G3MP2B3 levels) and in THF solution. In the case of methoxypyridines, the pKa values have also been calculated for complexes with LiCl and LiTMP.
A general method for copper-catalyzed arene cross-dimerization
Do, Hien-Quang,Daugulis, Olafs
supporting information; experimental part, p. 13577 - 13586 (2011/10/10)
A general method for a highly regioselective copper-catalyzed cross-coupling of two aromatic compounds using iodine as an oxidant has been developed. The reactions involve an initial iodination of one arene followed by arylation of the most acidic C-H bon
