Some Interconversion Reactions of Organolithium Compounds

Gilman, Henry; Langham, W.H.; Moore, Fred W.

doi:10.1021/ja01866a020

Cited by 213 publications

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“…The small intermolecular overlap is expected to reduce self quenching and the increase of fluorescence efficiency. [11b,16] In order to know how the fluorescence emissions of the dipyrenylbenzenes are influenced by the intermolecular interaction in the neat film samples, BSB (4,4′-bistriphenylsilanylbiphenyl, [17] see Scheme 1 for the structure) is used as the host matrix to dilute the dipyrenylbenzene in the co-deposited thin film. Various thin films doped with different dipyrenylbenzenes that have concentrations ranging from 1, 6, 17, 50, to 100 % (neat film) were prepared.…”

Section: Photophysical Properties In Dilute Solutions and Thin-film Smentioning

confidence: 99%

The Photophysical Properties of Dipyrenylbenzenes and Their Application as Exceedingly Efficient Blue Emitters for Electroluminescent Devices

Lin

et al. 2007

Adv Funct Materials

248

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Three blue‐light emitting dipyrenylbenzene derivatives, 1‐(4‐(1‐pyrenyl)phenyl)pyrene (PPP), 1‐(2,5‐dimethoxy‐4‐(1‐pyrenyl)phenyl)pyrene (DOPPP), and 1‐(2,5‐dimethyl‐4‐(1‐pyrenyl)phenyl)pyrene (DMPPP), have been prepared by the Suzuki coupling reaction of aryl dibromides with pyreneboronic acid in high yields. These compounds exhibit high glass‐transition temperatures of 97–137 °C and good film‐forming ability. As revealed from single‐crystal X‐ray analysis, these dipyrenylbenzenes adopt a twisted conformation with inter‐ring torsion angles of 44.5°–63.2° in the solid state. The twisted structure is responsible for the low degree of aggregation in the thin films that leads to fluorescence emission of the neat films at 446–463 nm, which is shorter than that of the typical pyrene excimer emission. The low degree of aggregation is also conducive for the observed high fluorescence quantum yields of 63–75%. In organic light‐emitting diode (OLED) applications, these dipyrenylbenzenes can be used as either the charge transporter or host emitter. The non‐doped blue OLEDs that employ these compounds as the emissive layer can achieve a very high external quantum efficiency (ηext) of 4.3–5.2%. In particular, the most efficient DMPPP‐based device can reach a maximum ηext of 5.2% and a very high luminescence of 40 400 cd m–2 in the deep‐blue region with Commission Internationale d'Énclairage (CIE) coordinates of (0.15, 0.11).

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Section: Photophysical Properties In Dilute Solutions and Thin-film Smentioning

confidence: 99%

The Photophysical Properties of Dipyrenylbenzenes and Their Application as Exceedingly Efficient Blue Emitters for Electroluminescent Devices

Lin

et al. 2007

Adv Funct Materials

248

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“…A possible reason for the increased diastereoselectivity observed with compounds 16-18 may be due to an unfavourable 1,3-diaxial interaction, which would exist between the C-3 side-chain methyl group and the oxygen atom of the ether bridge if the methyl group were axial in adducts [22][23][24] (Fig. 1); this 1,3-diaxial interaction is absent in adducts 19-21.…”

Section: Imdaf Reactions With Florisil In Rnethylene Chloridementioning

confidence: 99%

Diastereoselective intramolecular Diels–Alder reactions of the furan diene: the synthesis of (±)-1,4-epoxycadinane

Rogers¹,

Keay²

1993

Can. J. Chem.

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The diastereoselective intramolecular Diels-Alder reactions of the furan diene (IMDAF), in which the side arm comprises four carbon atoms and is substituted by a methyl group adjacent to, or one carbon removed from, the furan ring, are described. Adducts are formed in moderate to excellent yields when treated with either Florisil in methylene chloride at room temperature or methylaluminum dichloride in methylene chloride at -78°C. Florisil is most effective for substrates containing unsubstituted dienophiles. An equimolar quantity (1.1 equivalents) of methylaluminum dichloride is most effective for precursors having methacrolein-type dienophiles, while a catalytic quantity (0.1 equivalent) is effective for crotonaldehyde-type dienophiles. Only the adducts with the side arm orientated syn with respect to the oxygen bridge are detected and isolated. The major diastereomer is the one in which the methyl group (initially on the side arm) is situated equatorially on the newly formed six-membered ring. An application of the diastereoselective IMDAF reaction to the synthesis of (*)-l,4-epoxycadinane is described, beginning with 2-methylfuran.CHRISTINE ROGERS et BRIAN A. KEAY. Can. J. Chem. 71, 6 1 1 (1993).On dCcrit les reactions diastCrCosClectives de Diels-Alder intramolCculaires du furane (DAIMF) agissant comme diene et dans lequel la chaine laterale comporte quatre atomes de carbone et est substituke par un groupe mCthyle sur le carbone en a ou en p par rapport au noyau furanique. Les addults se forment avec des rendements allant de moyens a excellent~ lorsqu'on les traite soit avec du Florisil dans le chlorure de mCthylkne 2 la tempCrature ambiante soit avec du dichlorure de mCthylaluminium dans le chlorure de mCthylkne a -78°C. Le Florisil est le plus efficace pour les substrats contenant des diknophiles qui ne sont pas substitues. Une quantitC Cquimolaire (1,l equivalents) de dichlorure de mCthylaluminium est le plus efficace pour des diknophiles precurseurs du type mCthacrolCine alors qu'une quantitC catalytique (0,l equivalent) est efficace pour les dienophiles du type crotonaldChyde. On n'a detect6 et isolC que les adduits dont la chaine 1atCrale est orientCe en syrl par rapport au pont oxygCnC. Le diastereoisomkre principal est celui dans lequel le groupe mkthyle (initialement dans la chaine IatCrale) est en position Cquatoriale dans le cycle i six chainons nouvellement forme. On dCcrit une application de la rCaction diastCrCosClective Diels-Alder intramolCculaire du furane pour la synthkse du ( 2 ) -I ,4-6poxycadinane a partir du 2-mCthylfurane. [Traduit par la rCdaction]The intramolecular Diels-Alder reaction of the furan diene (IMDAF) has been studied by many groups since it was fust reported in 1978 (1). These investigations have attempted to define the scope and limitations of the LMDAF reaction with respect to (i) the effect of varying the length of the tether linking the diene and d i e n~~h i l e , ' .~(ii) the effect of substituting heteroatoms for carbon on the t e t h e~-,~.~ (iii) the effect of v...

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“…1,4-Dilithiobenzene (1 x mol) was prepared in hexane according to [9]. The solution of 1,4-dilithiobenzene was slowly added to the crude solution of 3 at -70°C.…”

Section: 4-bis(34-dirnethylphosphol-l -Yobenzenementioning

confidence: 99%

[1,5] Sigmatropic shifts in a 1,4‐diphospholylbenzene

Mercier

Mathey

1990

Heteroatom Chemistry

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The central phenylene ring o f I ,4-bis(3,4-dimethylphosphol-1-yobenzene undergoes [ I ,5] shifts around both phospholyl rings above 150°C to give 1,4-bis(3,4-dimethyl-SH-phosphol-2-yl)benzene, which can be trapped by tolane, [CpFe(CO)zlz, or Mn2 (CO)lo to yield the corresponding bis-1 -phosphanorbornadiene, bis-phosphafewocene, or bis-phosphacyman trene respectively. ture of the phosphole nucleus. The pyramidality of phosphorus reduces the cyclic delocalization within the 1-Hi-phosphole system and allows some overlap between the .n-dienic system and the (T orbital of the P-C exocyclic bond [ 6 ] .Recently, we became interested in all the possible techniques for building polyphosphole structures in order to create new polyphosphorus macrocycles, cages, and chains. Up to now, we have only been able to synthesize 2,2'-biphospholes 12, 71. In such a context, it was tempting to link together two phosphole rings via a para-phenylene bridge and to check whether it would be possible to promote the [ 1,5] sigmatropic shifts of the paraphenylene substituent around both phosphole rings of 1 in order to create new species derived from the original C-C bonded tricyclic structure 2 (Equation 2). The starting phosphole 1 was obtained by reaction of the recently discovered 1-cyano-3,4-dimethylphosphole 3 [8] with 1,4-diIn several previous papers [l-51, we have demonstrated that a 1-phenyl substituent could migrate from the phosphorus atom to the carbon atoms of a phosphole ring via a series of [1,5] sigmatropic shifts (Equation 1). These relatively easy migrations can be correlated with the pyramidal struc-1

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Some Interconversion Reactions of Organolithium Compounds

Cited by 213 publications

References 0 publications

The Photophysical Properties of Dipyrenylbenzenes and Their Application as Exceedingly Efficient Blue Emitters for Electroluminescent Devices

The Photophysical Properties of Dipyrenylbenzenes and Their Application as Exceedingly Efficient Blue Emitters for Electroluminescent Devices

Diastereoselective intramolecular Diels–Alder reactions of the furan diene: the synthesis of (±)-1,4-epoxycadinane

[1,5] Sigmatropic shifts in a 1,4‐diphospholylbenzene

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