38169-99-2Relevant academic research and scientific papers
Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2 H-Chromenes
Cervi, Aymeric,Vo, Yen,Chai, Christina L. L.,Banwell, Martin G.,Lan, Ping,Willis, Anthony C.
, p. 178 - 198 (2020/12/22)
Methods are reported for the efficient assembly of a series of phenol-derived propiolates, including the parent system 56, and their Au(I)-catalyzed cyclization (intramolecular hydroarylation) to give the corresponding coumarins (e.g., 1). Simple syntheses of natural products such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal X-ray analysis. A related process is described for the conversion of propargyl ethers such as 156 into the isomeric 2H-chromene precocene I (159), a naturally occurring inhibitor of juvenile hormone biosynthesis.
Isomers of Coumarin-Based Cyclometalated Ir(III) Complexes with Easily Tuned Phosphorescent Color and Features for Highly Efficient Organic Light-Emitting Diodes
Feng, Zhao,Yu, Yue,Yang, Xiaolong,Zhong, Daokun,Song, Dongdong,Yang, Hua,Chen, Xi,Zhou, Guijiang,Wu, Zhaoxin
, p. 7393 - 7408 (2019/06/11)
Three Ir(CλN)2(acac)-type and one Ir(C1λN)(C2λN)(acac)-type coumarin-based cyclometalated Ir(III) complex isomers (IrC5, IrC7, IrC7-A, and IrC8) have been obtained using three coumarin-based isomers of 2-phenylpyridine (ppy)-type cyclometalating ligands (L-C5, L-C7, and L-C8). Two coordination isomers emerging as principal products (IrC7 and IrC7-A) are obtained in the synthesis of corresponding coumarin-based cyclometalated Ir(III) complexes because of two different coordination sites in ligand L-C7 to form a C-Ir bond. To the best of our knowledge, there are no such isomers reported to date. Interestingly, a broad range of phosphorescent color tuning from green (IrC8, λ = 516 nm) to red (IrC5, λ = 608 nm) has been realized through variation of the pyridyl substitution positions on the fused phenyl ring of the coumarin skeleton. In addition, based on natural transition orbital (NTO) analyses, features of the lowest triplet excited states (T1) from these coumarin-based cyclometalated Ir(III) complex isomers can be tuned easily by these ligand isomers as well. IrC5, IrC7, and IrC7-A show prevailing 3MLCT character associated with their T1 states which emit the phosphorescent signals, while the T1 state of IrC8 exhibits the dominant ligand-centered π-π? transition feature. Importantly, owing to the strong rigidity of the coumarin skeleton, all the coumarin-based cyclometalated Ir(III) complex isomers can show high phosphorescent quantum yields φp (ca. 0.4-1). Together with the improved electron-injection/electron-transport (EI/ET) ability, all the phosphorescent emitters display impressive electroluminescence (EL) performance. The device based on IrC8 gives the highest EL efficiencies of external quantum efficiency (ηext) 22.7%, current efficiency (ηL) 79.7 cd A-1, and power efficiency (ηP) 58.2 lm W-1, representing the most state-of-the-art EL ability ever achieved by coumarin-based phosphorescent emitters. All these encouraging data definitely suggest the great potential of the coumarin skeleton in both easy tuning of the photophysical properties of ppy-type Ir(III) phosphorescent complexes and developing high-performance phosphorescent emitters.
Organometallic iridium complex phosphorescent material containing coumarin skeleton and preparation method of phosphorescent material
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Paragraph 0055; 0059-0063, (2019/04/26)
An organometallic iridium complex phosphorescent material containing a coumarin skeleton and a preparation method of the phosphorescent material are disclosed. The coumarin skeleton is introduced intoa traditional 2-phenylpyridine ligand, and through controlling the change of substitution positions and adopting an asymmetric structure type, double regulation and control of the luminescent wavelength and luminous efficiency of an obtained iridium complex is realized, so that the organic electrophosphorescent material having simple structure and excellent performance is obtained. By using the characteristics that the coumarin skeleton structure is highly rigid, simple, easy to synthesize, strong in luminescent property and the like, double regulation and control of the luminescent wavelength and luminous efficiency of the obtained iridium complex is realized.
Natural Product Chemistry. Part 121. Synthesis of Dicoumarinyl Ethers with the Structures Proposed for Fatagarine and Oreojasmine
Reisch, Johannes,Wickramasinghe, Anura,Kumar, Vijaya
, p. 1333 - 1339 (2007/10/02)
Synthesis of the 7,8'-dicoumarinyl ethers: 7-methoxy-7',8-oxydicoumarin and 6,7-dimethoxy-7',8-oxydicoumarin, established that the structures of fatagarine and oreojasmine for which these two structures have been proposed, have to be revised.Synthesis of 7-methoxy-5,7'-oxydicoumarin and 8-methoxy-7,7'-oxydicoumarin exclude the possibility of these dicoumarinyl ether structures for fatagarine. - Keywords: Dicoumarinyl ethers; 6,7-Dimethoxy-7',8-oxydicoumarin; Fatagarine; 7-Methoxy-5,7'-oxydicoumarin; 8-Methoxy-7,7'-oxydicoumarin; 7-Methoxy-7',8-oxydicoumarin; Oreojasmine; Ruta oreojasme
Natural Product Chemistry, Part 108. Synthesis of 7,7'-Oxy-dicoumarin, the Potential Precursor of Lasioerin and Gnidicoumarin (Short Communication)
Reisch, Johannes,Rosenthal, Bernd H. W.
, p. 871 - 874 (2007/10/02)
The synthesis of 7,7'-oxy-dicoumarin from 7-hydroxycoumarin and 7-bromocoumarin via Ullmann synthesis is described.In contrast to the literature, from the reaction of m-bromophenol with 2-hydroxy succinic acid, 7-bromocoumarin as well as 5-bromocoumarin were obtained. - Keywords: 7,7'-Oxy-dicoumarin; Ullmann-synthesis; 7- and 5-Bromocoumarin
