16883-69-5Relevant articles and documents
Synthesis of 2-aminoindolizines by 1,3-dipolar cycloaddition of pyridinium ylides with electron-deficient ynamides
Brioche, Julien,Meyer, Christophe,Cossy, Janine
, p. 2800 - 2803 (2015)
Electron-deficient ynamides, possessing an ynoate or an ynone moiety, have been successfully involved for the first time in a 1,3-dipolar cycloaddition with stabilized pyridinium ylides. These reactions afford an efficient and general access toward a variety of substituted 2-aminoindolizines which can serve as useful precursors for the synthesis of other more complex nitrogen heterocycles.
Synthesis of tetrasubstituted pyridazines via cascade reactions of diazocarbonyl compounds with pyridinium ylides
Tomilov,Platonov,Dorokhov,Zhalnina
, p. 1252 - 1256 (2008)
Reactions of pyridinium ylides with diazocarbonyl compounds involve the formation of functionalized azine intermediates that can undergo intramolecular cyclocondensation into tetrasubstituted pyridazines provided the starting reagents contain carbonyl groups. Reactions of pyridinium ylides with diazo compounds were studied for various substituents in both the substrates.
Stereoselective Cycloaddition of Pyridinium or Isoquinolinium Methylides with Olefinic Dipolarophiles and Subsequent Cycloadditions of the Cycloadducts with Nitrile Oxides
Tsuge, Otohiko,Kanemasa, Shuji,Takenaka, Shigeori
, p. 3631 - 3636 (1986)
Pyridinium or isoquinolinium methylides undergo highly stereo- and regioselective cycloadditions with olefinic dipolarophiles to form unstable tetrahydroindolizine derivatives.One of the two double bonds existing in the dihydro heteroaromatic ring of the cycloadducts reacts with nitrile oxides, in the same flask, in stereo-, regio-, and periselective fashions to lead to stable isoxazole-fused tetrahydroindolizines in good yields.
Benzoquinoline-based fluoranthene derivatives as electron transport materials for solution-processed red phosphorescent organic light-emitting diodes
Park, So-Ra,Shin, Dong Heon,Park, Sang-Mi,Suh, Min Chul
, p. 28520 - 28526 (2017)
A new electron transport material (ETM) with two fluoranthene and a benzoquinoline moiety was synthesized for the fabrication of solution-processed phosphorescent organic light-emitting diodes (PHOLEDs). In particular, we designed a bulky structure with a large twisted angle and improved thermal stability as compared to those of the common ETMs [e.g., 2,2′,2′′-(1,3,5-phenylene)tris(1-phenyl-1H-benzimidazole) (TPBI)] for device stability. As a result, we found that 4-(3-(fluoranthen-3-yl)-5-(fluoranthen-4-yl)phenyl)-2-phenyl-benzo[h]quinoline (FRT-PBQ) showed high glass transition temperature (Tg: ～184 °C) and moderately high electron transport behavior despite its bulky structural moieties. Moreover, we fabricated solution-processed red PHOLEDs with FRT-PBQ, and a relatively high current efficiency and external quantum efficiency of up to 20.7 cd A-1 and 15.5%, respectively, were achieved. In addition, the device lifetime was extended by a factor of 1.7 as compared to that of the device fabricated with TPBI as a common ETM.
Synthesis and characterisation of extended π-bonding systems in cycloimmonium ylides derived from the 4,4′-bipyridine
Depature, Ludovic,Surpateanu, Gheorghe
, p. 2239 - 2254 (2002)
Disubstituted cycloimmonium ylides derived from the 4,4'-bipyridine with one, two or four ylidic systems in their molecular structure are described as stable compounds. Synthesis of some bridged 1,1'-disubstituted 4,4'-bipyridinium dimethylides in which 1,4- or 1,3-phenylene spacers may be used, provide some new macromolecular cycloimmonium ylides with spatially extended π-bonding system. These compounds were obtained by the chemical conversion of 4,4'-bipyridinium salts as viologens or bis-viologens, with acylating or carbamoylating agents, in basic media. The characterisation of all compounds has been mainly performed by 1H and 13C NMR spectroscopy.
Computer-aided molecular design of solvents for accelerated reaction kinetics
Struebing, Heiko,Ganase, Zara,Karamertzanis, Panagiotis G.,Siougkrou, Eirini,Haycock, Peter,Piccione, Patrick M.,Armstrong, Alan,Galindo, Amparo,Adjiman, Claire S.
, p. 952 - 957 (2013)
Solvents can significantly alter the rates and selectivity of liquid-phase organic reactions, often hindering the development of new synthetic routes or, if chosen wisely, facilitating routes by improving rates and selectivities. To address this challenge, a systematic methodology is proposed that quickly identifies improved reaction solvents by combining quantum mechanical computations of the reaction rate constant in a few solvents with a computer-aided molecular design (CAMD) procedure. The approach allows the identification of a high-performance solvent within a very large set of possible molecules. The validity of our CAMD approach is demonstrated through application to a classical nucleophilic substitution reaction for the study of solvent effects, the Menschutkin reaction. The results were validated successfully by in situ kinetic experiments. A space of 1,341 solvents was explored in silico, but required quantum-mechanical calculations of the rate constant in only nine solvents, and uncovered a solvent that increases the rate constant by 40%.
Diversified Transformations of Tetrahydroindolizines to Construct Chiral 3-Arylindolizines and Dicarbofunctionalized 1,5-Diketones
Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Pan, Chenjing,Su, Zhishan,Wu, Zhikun,Zhang, Dong,Zhou, Yuqiao
supporting information, p. 15975 - 15985 (2020/10/18)
Enantioselective diverse synthesis of a small-molecule collection with structural and functional similarities or differences in an efficient manner is an appealing but formidable challenge. Asymmetric preparation and branching transformations of tetrahydroindolizines in succession present a useful approach to the construction of N-heterocycle-containing scaffolds with functional group, and stereochemical diversity. Herein, we report a breakthrough toward this end via an initial diastereo- A nd enantioselective [3 + 2] cycloaddition between pyridinium ylides and enones, following diversified sequential transformations. Chiral N,N′-dioxide-earth metal complexes enable the generation of optically active tetrahydroindolizines in situ, across the strong background reaction for racemate-formation. In connection with deliberate sequential transformations, involving convenient rearomatic oxidation, and light-active aza-Norrish II rearrangement, the tetrahydroindolizine intermediates were converted into the final library including 3-arylindolizine derivatives and dicarbofunctionalized 1,5-dicarbonyl compounds. More importantly, the stereochemistry of four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axial chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridged cyclic compounds were also discovered depending on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the reaction processes.
