- First-order hyperpolarizability of oligo-acene derivatives by hyper-Rayleigh scattering
-
First-order hyperpolarizabilities β for a series of oligo-acene derivatives were estimated as a function of the conjugation length by means of the hyper-Rayleigh scattering (HRS) technique. Satisfactory data acquisition and analyses gave the hyperpolarizabilities (17 ± 2) × 10-30 and (68 ± 8) × 10-30 esu for naphthalene-2,3-dialdehyde and anthracene-2,3-dialdehyde, respectively. The pure β value of tetracene-2,3-dialdehyde (OA4) could not be determined because of multiphoton absorption induced fluorescence superimposed on the HRS signal. A large β value (≈ 180 × 10-30 esu) is expected for OA4 by extrapolating the conjugation length dependence on β.
- Ishibashi, Kenichi,Iyoda, Tomokazu,Hashimoto, Kazuhito,Fujishima, Akira,Shirai, Yasuo,Jiro, Abe
-
-
Read Online
- A solvent-free mechanochemical synthesis of polyaromatic hydrocarbon derivatives
-
Polyaromatic hydrocarbons are central molecules in the future of nanotechnology. However, the synthesis of these molecules is limited by their lack of solubility in solvents, especially green solvents, their ease of oxidation in solution and use of harmful reagents. Solvent-free mechanochemistry has been shown to have excellent potential for these types of molecules and should provide a much more environmentally benign approach for the synthesis of this very important class of molecules. This report details the use of mechanochemistry on an iterative strategy for the synthesis of polyaromatic hydrocarbon derivatives.
- Wang, Cong,Hill, Malik,Theard, Brandon,MacK, James
-
p. 27888 - 27891
(2019/09/30)
-
- Heptacene: Characterization in Solution, in the Solid State, and in Films
-
Acenes comprise an important class of organic semiconducting materials. As graphene nanoribbons of ultimate width, they are valuable atom-precise model systems for studying the properties of this form of nanoscale carbon materials. Heptacene is the smallest member of the acene series that could only be studied under matrix isolation conditions. Its existence in bulk had never been positively confirmed, despite efforts dating back more than 70 years. We report that the reduction of 7,16-heptacenequinone produces a mixture of two diheptacene molecules. The diheptacenes undergo thermal cleavage to heptacene at high temperatures in the solid state. Monitoring this cycloreversion by solid state 13C cross-polarized magic angle spinning NMR reveals that solid heptacene has a half-life time of several weeks at room temperature. The diheptacenes are valuable precursors for generating films of heptacene by vapor phase deposition that can be studied below or at room temperature.
- Einholz, Ralf,Fang, Treliant,Berger, Robert,Grüninger, Peter,Früh, Andreas,Chassé, Thomas,Fink, Reinhold F.,Bettinger, Holger F.
-
p. 4435 - 4442
(2017/04/03)
-
- Sc(OTf)3-Catalyzed [3 + 3] Cycloaddition of Cyclopropane 1,1-Diesters with Phthalazinium Dicyanomethanides
-
The Sc(OTf)3-catalyzed diastereoselective [3 + 3] cycloaddition of phthalazinium dicyanomethanides with cyclopropane 1,1-diesters proceeded smoothly under mild reaction conditions, affording a variety of 3,4-dihydro-1H-pyrido[2,1-a]phthalazine derivatives in up to 99% yields with excellent diastereoselectivities.
- Liu, Honglei,Yuan, Chunhao,Wu, Yang,Xiao, Yumei,Guo, Hongchao
-
supporting information
p. 4220 - 4223
(2015/09/15)
-
- Phosphine-Mediated Iterative Arene Homologation Using Allenes
-
A PPh3-mediated multicomponent reaction between o-phthalaldehydes, nucleophiles, and monosubstituted allenes furnishes functionalized non-C2-symmetric naphthalenes in synthetically useful yields. When the o-phthalaldehydes were reacted with 1,3-disubstituted allenes in the presence of PPh2Et, naphthalene derivatives were also obtained in up to quantitative yields. The mechanism of the latter transformation is straightforward: aldol addition followed by Wittig olefination and dehydration. The mechanism of the former is a tandem γ-umpolung/aldol/Wittig/dehydration process, as established by preparation of putative reaction intermediates and mass spectrometric analysis. This transformation can be applied iteratively to prepare anthracenes and tetracenes using carboxylic acids as pronucleophiles.
- Zhang, Kui,Cai, Lingchao,Jiang, Xing,Garcia-Garibay, Miguel A.,Kwon, Ohyun
-
p. 11258 - 11261
(2015/09/21)
-
- Cycloadditions of siloxy alkynes with 1,2-diazines: From reaction discovery to identification of an antiglycolytic chemotype
-
Cycloaddition uncovered: The title reaction produces novel polycyclic compounds with high efficiency and excellent diastereoselectivity under mild reaction conditions. A small-molecule library, synthesized using this reaction, yielded a novel chemotype which inhibited glycolytic ATP production by blocking glucose uptake in CHO-K1 cells. DMF=N,N-dimethylformamide, Tf= trifluoromethanesulfonyl, TIPS=triisopropylsilyl. Copyright
- Montavon, Timothy J.,Tuerkmen, Yunus E.,Shamsi, Noumaan A.,Miller, Christopher,Sumaria, Chintan S.,Rawal, Viresh H.,Kozmin, Sergey A.
-
p. 13576 - 13579
(2014/01/06)
-
- Silver-catalyzed formal inverse electron-demand diels-alder reaction of 1,2-diazines and siloxy alkynes
-
A highly effective silver-catalyzed formal inverse electron-demand Diels-Alder reaction of 1,2-diazines and siloxy alkynes has been developed. The reactions provide ready access to a wide range of siloxy naphthalenes and anthracenes, which are formed in good to high yields, under mild reaction conditions, using low catalyst loadings.
- Tuerkmen, Yunus E.,Montavon, Timothy J.,Kozmin, Sergey A.,Rawal, Viresh H.
-
p. 9062 - 9065
(2012/07/14)
-
- Two chemodivergent anionic domino processes from cyclic α-nitroketones and aromatic aldehydes
-
Treatment of cyclic α-nitroketones and aromatic 1,2-dialdehydes with DBU in tetrahydrofuran containing small amounts of water proceeded through two chemodivergent one-pot domino pathways, whose outcome depended on the ring size of the starting nitroketone. Thus, α-nitrocyclohexanone underwent diastereoselective α′-arylmethylenation reactions through a nitroaldol/aldol/reverse nitroaldol mechanism. On the other hand, α-nitrocycloheptanone and α-nitrocyclooctanone afforded 2-nitroindane-1,2-diols containing three contiguous stereocenters in a highly diastereoselective fashion through a nitroaldol/retro-Dieckmann/intramolecular nitroaldol process.
- Giorgi, Giorgio,Arroyo, Francisco J.,López-Alvarado, Pilar,Menéndez, J. Carlos
-
experimental part
p. 5582 - 5589
(2011/08/10)
-
- Iterative synthesis of acenes via homo-elongation
-
Starting from aromatic ortho-dialdehydes, we devised a homo-elongation protocol that combines a Wittig olefination and subsequent intramolecular Knoevenagel condensation to produce acene diesters and dinitriles. The Royal Society of Chemistry.
- Lin, Chih-Hsiu,Lin, Ke-Han,Pal, Bikash,Tsou, Li-Der
-
supporting information; experimental part
p. 803 - 805
(2009/07/10)
-
- The Bergman reaction as a synthetic tool: Advantages and restrictions
-
The Bergman cycloaromatization reaction efficiently converts easily prepared acyclic enediynes into aromatic rings. In order to prepare larger, functionalized fused aromatic systems using this reaction, a thorough understanding of how functionalization affects cycloaromatization is necessary. We present here our studies on the influence of substituents at three different functionalization sites on cycloaromatization, and how these functional groups can be tailored to prepare more complex systems.
- Bowles, Daniel M,Palmer, Grant J,Landis, Chad A,Scott, John L,Anthony, John E
-
p. 3753 - 3760
(2007/10/03)
-
- Synthesis of Benzo-Fused Tetraphenylenes and Crystal Structure of a 4:1 Clathrate Inclusion Compound of Dibenzotetraphenylene with p-Xylene
-
Benzo-fused tetraphenylenes 2-6 were successfully prepared by the combined deployment of the Diels-Alder cycloaddition between some strained cyclooctynes and furans and subsequent low-valent-titanium deoxygenation of the resulting 1,4-endoxides.As expecte
- Man, Yuet-Ming,Mak, Thomas C. W.,Wong, Henry N. C.
-
p. 3214 - 3221
(2007/10/02)
-
- New Derivatizing Agents for Amino Acids and Peptides. 1. Facile Synthesis of N-Substituted 1-Cyanobenzisoindoles and Their Spectroscopic Properties
-
2,3-Naphthalenedicarboxaldehyde (NDA) is shown to be a very useful reagent for the derivatization of primary amines, amino acids, and small peptides.The reaction of these amino compounds with NDA and cyanide ion produces highly fluorescent 2-substituted 1-cyanobenzisoindoles that are relatively stable.The physical and fluorescent properties of a variety of 1,2-disubstituted benzisoindoles are presented.
- Carlson, R. G.,Srinivasachar, K.,Givens, R. S.,Matuszewski, B. K.
-
p. 3978 - 3983
(2007/10/02)
-
- 1H NMR Study of Two Tetrahydrocyclodecabiphenylenes
-
5,6,9,10-Tetradehydrobenzocyclodecabiphenylene (2) and 5,6,9,10-tetrahydronaphthocyclodecabiphenylene (3) were prepared by a "bis-Wittig reaction between 1,8-bis((triphenylphosphoranylidene)methyl)biphenylene (5) an
- Wilcox, Charles F,,Weber, Karl A.
-
p. 1088 - 1094
(2007/10/02)
-
- BARIUM MANGANATE. A VERSATILE OXIDANT IN ORGANIC SYNTHESIS.
-
Preparation of barium manganate in large-scale is discussed. It is also shown that this reagent is capable of oxidizing organic substrates, converting alcohols to their corresponding carbonyl compounds, aromatic amines to their corresponding azo compounds, hydroquinone to p-benzoquinone, benzylamine to benzaldehyde, and triphenylphosphine to its oxide in good yields. Saturated hydrocarbons, unsaturated hydrocarbons, unsaturated ketones, and saturated amines are not affected by this reagent in a reasonable reaction time.
- Firouzabadi,Mostafavipoor
-
p. 914 - 917
(2007/10/02)
-
