Photoinduced Charge Separation in Rigid Bichromophoric Compounds and Charge Transfer State Electron Transfer Reactivity
摘要:
Bichromophoric compounds giving, after photoexcitation, a locally excited state (LE) rapidly followed by an intramolecular charge transfer (CT) state were designed using a Paddon-Row type synthesis. The electron-accepting end of the CT state is chosen in order to play the role of an electron relay versus external accepters. In this way, electron transfer photosensitization is made available by using the CT state of bichromophores. The photophysics of the synthesized bichromophores is discussed; and the reductive dechlorination of polychlorinated benzenes is used as a test reaction. The bichromophoric sensitizer is unexpectedly found to be totally regenerated: the reaction is shown to be initiated by an electron transfer from the CT state to the chlorinated quencher. A rapidly breaking radical anion leads to the dechlorination, while the recombination of the sensitizer radical cation with the released chloride anion opens the way to the sensitizer recovery.
Toward a mild dehydroformylation using base-metal catalysis
作者:Dylan J. Abrams、Julian G. West、Erik J. Sorensen
DOI:10.1039/c6sc04607j
日期:——
biosynthesis of cholesterol and related sterols under mild conditions using base-metal catalysts. In contrast, chemists have recently developed a non-oxidative dehydroformylation method; however, it requires high temperatures and a precious-metal catalyst. Careful study of both approaches has informed our efforts to design a base-metal catalyzed, mild dehydroformylation method that incorporates benefits from
Electron-transfer substitution reactions: Facilitation by the cyano group
作者:Nathan Kornblum、Michael J. Fifolt
DOI:10.1016/0040-4020(89)80129-2
日期:1989.1
It is now clear that a cyane group facilitate electron-transfersubstitutionreactions. of particular interest is the demonstration that electron-transfer chain substitution at a staturated carbon atom has been achieved in the absence of a nitro group.
Versatile palladium-catalyzed arylation of organomanganese chlorides by aryl bromides
作者:Eric Riguet、Mouâd Alami、Gérard Cahiez
DOI:10.1016/s0022-328x(00)00891-3
日期:2001.4
In THF, a palladium-catalyzed cross-coupling reaction of organomanganese reagents with various aryl bromides including unreactive deactivated or hindered aryl bromides was performed successfully in the presence of a new catalytic system 1% PdCl2(dppp)-four equivalents DME. The scope of the reaction is very broad since many functional groups are tolerated, moreover, even hindered O,O ' -di- or trisubstituted diaryls were obtained in E;igh yields. It is interesting to note that hindered aryl bromides are more reactive than the corresponding aryl iodides. Alkyl, alkenyl and alkynylmanganese chlorides also react under similar conditions. (C) 2001 Elsevier Science B.V. All rights reserved.
KORNBLUM, NATHAN;FIFOLT, MICHAEL J., TETRAHEDRON, 45,(1989) N, C. 1311-1322