Thermally Stable Nonaggregating Pyrenylarenes for Blue Organic Light-Emitting DevicesCDRI communication No. 8097.

Abstract

A new series of thermally stable blue light-emitting nonplanar pyrenylarenes having an amine donor and a nitrile acceptor group was prepared from a ketene-S,S-acetal under conventional heating and/or microwave irradiation. The photophysical, electrochemical, and optical behavior of donor-acceptor pyrenylarenes are demonstrated. The performance of blue light-emitting pyrenylarenes was investigated by fabricating a multilayer device with the device configuration of ITO/PEDOT:PSS (40 nm)/NPB (30 nm)/pyrenylarene (55 nm)/BCP (8 nm)/LiF (0.6 nm)/Al (200 nm), which exhibited low turn-on voltage (5 V) with luminance efficiency of 0.8 Cd/A with nonaggregation behavior in both solution and solid state.

Recent developments of ketene dithioacetal chemistry

“…169,170 Later, Tominaga et al reported the synthesis of methyl 6-aryl-and 6-styryl-4-methylthio-2-oxo-2H-pyran-3carboxylates from reaction of aryl and styryl methyl ketones with dimethyl bis(methylthio)methylenemalonate in the presence of potassium hydroxide in DMSO solvent. 171 Recently, Goel and co-workers expanded the [3 + 3] methodology and its synthetic utility, [172][173][174][175][176] for example, the reaction of methyl 2-cyano-3,3-bis(methylthio)acrylate 299 with 1-(pyren-1-yl)ethanone under basic conditions furnished a-pyrons 300 in 88% yield via a 1,4-addition/methylthio elimination/enol lactonization sequence (Scheme 82). 173 Replacement of the methylthio group of 300 with an amine (piperidine) can furnish 2-oxo-4-(piperidin-1-yl/4-methylpiperidin-1-yl)-6-(pyren-1-yl)-2H-pyran-3-carbonitrile 303 in quantitative yields.…”

“…171 Recently, Goel and co-workers expanded the [3 + 3] methodology and its synthetic utility, [172][173][174][175][176] for example, the reaction of methyl 2-cyano-3,3-bis(methylthio)acrylate 299 with 1-(pyren-1-yl)ethanone under basic conditions furnished a-pyrons 300 in 88% yield via a 1,4-addition/methylthio elimination/enol lactonization sequence (Scheme 82). 173 Replacement of the methylthio group of 300 with an amine (piperidine) can furnish 2-oxo-4-(piperidin-1-yl/4-methylpiperidin-1-yl)-6-(pyren-1-yl)-2H-pyran-3-carbonitrile 303 in quantitative yields. The a-pyrone ring of 303 can be converted into thermally stable nonaggregating pyrenylarenes 304 (for blue organic light-emitting devices) upon reaction with aliphatic aldehydes in the presence of KOH in DMF at room temperature for 12-14 h via ring transformation (recently termed lactone methodology, Scheme 82).…”

“…The a-pyrone ring of 303 can be converted into thermally stable nonaggregating pyrenylarenes 304 (for blue organic light-emitting devices) upon reaction with aliphatic aldehydes in the presence of KOH in DMF at room temperature for 12-14 h via ring transformation (recently termed lactone methodology, Scheme 82). 173 Recently, we reported an efficient AlCl 3 -mediated C-C coupling between readily available a-hydroxy ketene dithioacetals 307 with various electron-rich arenes through the direct substitution of the hydroxy group of 307. 177 On the basis of the C-C coupling, 3,4-disubstituted dihydrocoumarins 309, 310 and chromenes 311 were prepared in high yields through Friedel-Crafts alkylation followed by intramolecular annulation (Scheme 83).…”

Synthesis of Fluorescent C2-Bridged Teraryls and Quateraryls for Blue, Sky-Blue, and Green Color Light-Emitting Devices

“…20 6-(Biphenyl-4-yl)-4-(methylsulfanyl)-2-oxo-2H-pyran-3-carbonitrile (3c). Yellow solid (1.98 g, 62% yield); R f = 0.55 (chloroform/ methanol, 99:1, v/v); mp (chloroform/methanol) > 250°C; MS (ESI) 320 [M + H] + ; IR (KBr) ν = 1708, 2211; 1 H NMR (300 MHz, DMSO-d 6 ) δ 2.87 (s, 3H), 7.30 (s,1H),3H),7.80 (d,J = 8.5 Hz,2H),7.91 (d,J = 8.5 Hz,2H),8.15 (d,J = 8.5 Hz, 2H) ppm; 13 C NMR (100 MHz, DMSO-d 6 ) δ = 14.8,89.9,105.3,114.7,124.5,125.3,126.8,127.1,127.4,127.6,128.3,129.9,130.1,130.5,131.1,133.6,158.2,163.8,171.8;HRMS (ESI) 14.9,88.7,98.7,114.7,120.5,132.7,133.5,135.1,156.1,156.9,171.8;HRMS (ESI) 7,26.6,50.8,70.6,101.2,118.2,125.3,125.7,127.1,128.0,128.8,129.1,…”

Base-Promoted Selective Synthesis of 2H-Pyranones and Tetrahydronaphthalenes via Domino Reactions

“…6 Especially, 6-aryl-4-(methylthio/amine-1-yl)-2-oxo-2 H -pyran-3-carbonitriles are versatile intermediates in the synthesis of various heterocycles/carbocycles 7 and different D–A-containing heteroaromatic 8 or polycyclic organic fluorophores. 9 The other 4 H -pyranone and fused pyranone derivatives are also known to possess red EL properties and dye lasers. 10 Furthermore, Komatsu et al reported the fluorescence properties of highly substituted pyranone (3,4,6-triphenyl-2 H -pyrones) and its relevant compounds.…”