A New Organocatalytic Process of Cyclotrimerization of Acetylenic Ketones Mediated by 2,4-Pentanedione
作者:Song Xue、Qing-Fa Zhou、Fei Yang、Qing-Xiang Guo
DOI:10.1055/s-2007-967997
日期:2007.2
organocatalytic process of cyclotrimerization of the aliphatic and aromatic acetylenic ketones was developed. The reaction catalyzed by DMAP in the presence of 2,4-pentanedione gave 1,3,5-trisubstituted benzenes in almost quantitative yields under very mild conditions. 2,4-Pentanedione was used as a cocatalyst to promote the reaction efficiently, particularly for aliphatic acetylenic ketones.
The unusual transformation of β-aryl-β-haloacroleins into valuable triaroylbenzenes is reported by the first time. The convenient sequence takes advantage on the one step access to triaroylbenzenes. This work establishes that the presence of amine is required for the trimerization procedure since it is involved in the formation of iminium–enamine intermediate A.
Novel star-shaped yellow thermally activated delayed fluorescence emitter realizing over 10% external quantum efficiency at high luminance of 30000 cd m−2 in OLED
Thermallyactivateddelayedfluorescence (TADF) mechanism has been considered as the most attractive approach for organic light emitting diodes (OLEDs) due to its full exciton utilization with pure organic emitters. However, most TADF-based OLEDs still suffer two important issues — low maximum luminance and severe efficiency roll-off, which hinder their further development. Herein, a novel star-shaped
热活化延迟荧光(TADF)机理已被认为是有机发光二极管(OLED)最具吸引力的方法,因为其与纯有机发射体的激子充分利用。但是,大多数基于TADF的OLED仍然面临两个重要问题-低最大亮度和严重的效率下降,这阻碍了它们的进一步发展。在此,设计并合成了一种新型的星形黄色TADF发射体苯-1,3,5-三基三((4-(10H-苯恶嗪-10-基)苯基)甲酮)(TBP-PXZ)。由于边界分子之间的分离良好,TBP-PXZ表现出微小的单重态-三重态能隙,因此具有显着的TADF特性。使用TBP-PXZ作为发射器,OLED具有出色的电致发光性能,最大EQE为17.7%。而且,分别在30000 cd m -2的亮度下为-2和10.5%。这些结果表明,TBP-PXZ是开发具有高最大亮度和低效率滚降的TADF发射器的理想模型。