55135-66-5Relevant articles and documents
Synthesis of Kainoids and C4 Derivatives
Tian, Zhenlin,Menard, Frederic
, p. 6162 - 6170 (2018/05/23)
A unified stereoselective synthesis of 4-substituted kainoids is reported. Four kainic acid analogues were obtained in 8-11 steps with up to 54% overall yields. Starting from trans-4-hydroxy-l-proline, the sequence enables a late-stage modification of C4 substituents with sp2 nucleophiles. Stereoselective steps include a cerium-promoted nucleophilic addition and a palladium-catalyzed reduction. A 10-step route to acid 21a was also established to enable ready functionalization of the C4 position.
Fluorene-based organic compound and application thereof on OLED device
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Paragraph 0062; 0066; 0067, (2018/03/26)
The invention relates to a fluorene-based organic compound and application thereof on an OLED device. A structure of the compound is that fluorine is connected with a hexatomic ring structure of a benzo hexatomic ring through a carbon-carbon bond, so that material chemical stability is improved and active positions of a branch chain radical are prevented from being exposed through the carbon-carbon bond connection; the whole molecule is a relatively great rigid structure, and has relatively high triplet-state energy level (T1); moreover, steric hindrance is great, rotation is not liable to occur and the three-dimensional space structure is more stable, so that the compound has a relatively high glass transition temperature and relatively high molecule thermal stability; besides, distribution positions of HOMO and LUMO of the compound are separated from each other, so that the fluorene-based organic compound has proper HOMO and LUMO energy level; and after the compound is applied to theOLED device, light-emitting efficiency of the device can be effectively improved, and the service life of the device can be effectively prolonged.
Alkyl substituent effects on pipecolyl amide isomer equilibrium: Efficient methodology for synthesizing enantiopure 6-alkylpipecolic acids and conformational analysis of their N-acetyl N'-methylamides
Swarbrick, Martin E.,Gosselin, Francis,Lubell, William D.
, p. 1993 - 2002 (2007/10/03)
Enantiopure 6-alkylpipecolic acid hydrochlorides 1a-e were synthesized in five steps and 15-59% overall yields from α-tert-butyl β-methyl N- (PhF)aspartate (3) via an approach featuring selective hydride reduction to the corresponding aspartate β-aldehyde 2, aldol condensations with the enolates of various methyl alkyl ketones, and diastereoselective intramolecular reductive aminations. The influence of the 6-position substituent on the equilibrium and the energy barrier for isomerization of the amide N-terminal to pipecolate was then explored via the synthesis of N- acetyl N'-methylpipecolinamide (16) and its (2S,6R)-6-tert- butylpipecolinamide counterpart 17, and their conformational analysis by proton NMR spectroscopy and coalescence experiments. The presence of the tert-butyl substituent augmented the population of the amide cis-isomer and lowered the barrier for pipecolyl amide isomerization in water. Compared with the results from our previous examination of N-acetyl-5-tert-butylproline N'- methylamides (Beausoleil, E.; Lubell, W. D. J. Am. Chem. Soc. 1996, 118, 12902), the consequences of the bulky 6-alkyl substituent on the acetamide geometry and isomerization barrier were less pronounced in the pipecolate series relative to the respective proline amides.
