27370-85-0Relevant academic research and scientific papers
Photochemistry of linear-shaped phenylacetylenyl- and (phenylacetylenyl) phenylacetylenyl-substituted aromatic enediynes
Sugiyama, Yoko,Shinohara, Yoshihiro,Momotake, Atsuya,Takahashi, Kayori,Kanna, Yoko,Nishimura, Yoshinobu,Arai, Tatsuo
scheme or table, p. 10929 - 10935 (2011/02/17)
The series of linear-shaped phenylacetylenyl- and (phenylacetylenyl) phenylacetylenyl-substituted aromatic enediynes 1-3 were synthesized as pure trans and cis isomers and their photochemistry explored. With expansion of the π-electron system, the absorpt
Photoisomerization of all-cis-1,6-diphenyl-1,3,5-hexatriene in the solid state and in solution: A simultaneous three-bond twist process
Saltiel, Jack,Papadimitriou, Dimitrios,Krishna, Tallapragada S. R.,Huang, Zhen-Nian,Krishnamoorthy, Govindarahan,Laohhasurayotin, Somchoke,Clark, Ronald J.
scheme or table, p. 8082 - 8085 (2010/01/16)
Disrotatory bicycle pedals: Irradiation of the title compound in the solid state gives the all-trans isomer directly in a crystal-to-crystal reaction. This threefold cis-trans photoisomerization is proposed to proceed by a two-stage mechanism that is consistent with two simultaneous bicyclepedal processes occurring in disrotatory fashion about the central bond.
A p-benzyne to m-benzyne conversion through a 1,2-shift of a phenyl group. Completion of the benzyne cascade
Polishchuk, Alexei L.,Bartlett, Kevin L.,Friedman, Lee A.,Jones Jr., Maitland
, p. 798 - 806 (2007/10/03)
Pyrolysis of 1,6-diphenylhexa-1,5-diyne-cis-3-ene at 800-1000 °C leads to a mixture of 1- and 2-phenylbiphenylene, along with triphenylene. Formation of the two biphenylenes is taken as strong evidence of the rearrangement of a p-benzyne into a m-benzyne through a shift of one of the phenyl groups. Copyright
A direct route to conjugated enediynes from dipropargylic sulfones by a modified one-flask Ramberg-Baecklund reaction
Cao, Xiaoping,Yang, Yuying,Wang, Xiaolong
, p. 2485 - 2489 (2007/10/03)
The reaction of dipropargylic sulfones with dibromodifluoromethane in the presence of alumina-supported KOH in dichloromethane solution results in facile rearrangement affording the corresponding conjugated linear and cyclic enediynes in good yields. This result shows that the direct transformation of a- and a′-hydrogen bearing sulfones assembles enediyne units without resorting to the prior preparation of the a-halo sulfone precursors in a separate step.
An iterative approach to cis-oligodiacetylenes
Kosinski, Christoph,Hirsch, Andreas,Heinemann, Frank W.,Hampel, Frank
, p. 3879 - 3890 (2007/10/03)
Phenyl-terminated cis-oligodiacetylenes such as 18, containing a π-conjugated backbone with four triple and three double bonds, were synthesized using Pd-catalysed Sonogashira coupling reactions. Compound 18 represents the longest cis-oligoenyne system to date, but it suffers from the drawback of cis/trans isomerization observed in solution. In order to avoid cis/trans isomerization in such cis-oligodicacetylenes, the ene moieties within the oligomeric backbone were locked by incorporation into ring systems. 1,2-Dibromocyclopentene was used as an olefinic building block for this purpose, permitting the iterative synthesis of the cis-oligodiacetylenes 27 and 28, possessing the same π-conjugated backbone as 18. Unlike that compound, however, 27 and 28 are stable both in solution and in the solid state. Whereas X-ray crystallography revealed a completely planar structure for 27 in the single crystal, NMR and computational investigations suggest that a preferred helical conformation is likely in solution.
Novel finding of the effect of triple bond on the photochemical cis-trans isomerization of C=C double bond
Sakakibara, Hirokazu,Ikegami, Masashi,Isagawa, Kakuzo,Tojo, Sachiko,Majima, Tetsuro,Arai, Tatsuo
, p. 1050 - 1051 (2007/10/03)
Both cis- and trans-1,2-bis(phenylethynyl)ethenes (1) gave fluorescence emission with considerably high quantum yield and intersystem crossing to the triplet state which underwent cis-trans isomerization. On the basis of the results, a novel potential energy surface of isomerization of 1 was proposed.
A direct and stereocontrolled route to conjugated enediynes
Jones, Graham B.,Wright, Justin M.,Plourde, Gary W.,Hynd, George,Huber, Robert S.,Mathews, Jude E.
, p. 1937 - 1944 (2007/10/03)
A unified synthetic route to 3-hex-en-1,5-diynes, a key building block found in many of the enediyne antitumor agents and designed materials, was developed. The method, which relies on a carbenoid coupling-elimination strategy is tolerant of a wide range of functionalities, and was applied to the synthesis of a variety of linear and cyclic enediynes. Reaction parameters can be adjusted to control stereoselectivity of the process, producing linear enediynes from 1:12 to >100:1 E:Z ratio, and in the case of cyclic enediynes, giving the exclusively Z C-9, C-10, or C-11 products. Key features of the process are the ready availability of precursors and the mildness and efficiency of the reaction. Application of the process in the design of materials precursors and preparation of enediyne antitumor agents are presented.
Direct conversion of dipropargylic sulfones into (E)- and (Z)-Hex-3-ene-1,5-diynes by a modified one-flask Ramberg-Backlund reaction
Cao,Chan,Chow
, p. 1049 - 1052 (2007/10/03)
(E)- and (Z)-enediynes 7 are readily synthesized in good yields from a one-pot modified Ramberg-Backlund reaction from dipropargylic sulfones 5.
?-Complexes incorporating tetrakis(phenylethynyl)ethene
Philp, Douglas,Gramlich, Volker,Seiler, Paul,Diederich, Francois
, p. 875 - 886 (2007/10/02)
Tetrakis(phenylethynyl)ethene and the ?-acceptors 2,4,7-trinitrofluoren-9-one and (2,4,7-trinitrofluoren-9-ylidene)malononitrile form highly ordered donor-acceptor ?-complexes having 1:2 stoichiometry in the solid state.In solution, relatively weak 1:1 co
Carbene-carbene interconversion between 1- and 3-phenyl-2-propynylidenes
Noro, Masaki,Masuda, Takeshi,Ichimura, Andrew S.,Koga, Noboru,Iwamura, Hiizu
, p. 6179 - 6190 (2007/10/02)
1-Phenyl-3-diazopropyne (1d) and 3-phenyl-3-diazopropyne (2d) were prepared and photolyzed under various conditions. In ethanol at ambient temperatures, both 1d and 2d gave a 1:10 ± 1 mixture of 1-phenyl-3-ethoxypropyne (3) and 3-phenyl-3-ethoxypropyne (4). The photolyses of matrix-isolated 1d and 2d at cryogenic temperatures were followed by EPR, IR, and UV-visible spectroscopy. EPR experiments in 2-methyltetrahydrofuran (MTHF), isopentane, and ethanol-d6 matrices at 9 K showed spectra due to a mixture of the corresponding triplet carbenes 1c (D/hc = 0.543 and |E/hc| = 0.003 cm-1) and 2c (D/hc = 0.526 and |E/hc| = 0.010 cm-1). The ratio of the generated carbenes carried the memory of the starting diazo compounds; 1c and 2c were produced mainly from 1d and 2d, respectively. Carbene 2c isomerized to 1c at 70-90 K in MTHF and ethanol-d6 and at 44-68 K in isopentane, indicating that 1c was thermodynamically more stable than 2c on the triplet ground-state potential energy surface. IR and UV-visible absorption experiments employing various media (argon, isopentane, N2, CO/Ar, O2/N2, and O2/Ar) revealed that the photolysis of 2d afforded mostly absorptions due to 2c. Photolysis of 1d produced similar spectra, due mainly to 2c, together with weak absorptions due to 1c. The different results observed in EPR and IR experiments were explained by the difference in the matrices in which the diazo groups were photolyzed. Calculations at the ab initio MP2/DZV(d) level of theory showed that the triplet ground state of 1c was more thermodynamically stable than 2c by 1.41 kcal/mol, in agreement with the experimental results. The situation is reversed in the singlet manifold, where 2c was computed to be much lower in energy than 1c. The energy differences (ΔEST) between the singlet and triplet states were computed to be 15.7 and 11.0 kcal/mol for 1c and 2c, respectively, with the DZV(d) basis set.
