Large-Scale Preparation of Aromatic Fluorides via Electrophilic Fluorination with Functionalized Aryl- or Heteroarylmagnesium Reagents
作者:Paul Knochel、Shigeyuki Yamada
DOI:10.1055/s-0029-1218816
日期:2010.7
Functionalized aryl- or heteroarylmagnesium reagents, prepared from the corresponding bromides or iodides using halogen-magnesium exchange or direct magnesium insertion in the presence of lithiumchloride, reacted smoothly with N-fluorobenzenesulfonimide, (PhSO2)2NF, in the mixedsolvent (4:1 CH2Cl2-perfluorodecalin) to give the corresponding aromatic fluorides in moderate to good yields. arenes - electrophilic
Give me an “F”: Electrophilic fluorination of various aromatic and heteroaromatic Grignardreagents is smoothly performed with (PhSO2)2NF as fluorinating agent in a 4:1 mixture of CH2Cl2/perfluorodecalin (see scheme). This solvent system allows minimization of most side reactions.
3,4-Dihydro-3<i>H</i>-pyrrol-2-imines as Conformationally Restrained 1,3-Diazabutadienes: Synthesis, Structural Properties and Protonation
作者:Simon Janich、Roland Fröhlich、Andrea Wilken、Jan von Zamory、Atsushi Wakamiya、Shigehiro Yamaguchi、Ernst-Ulrich Würthwein
DOI:10.1002/ejoc.200900045
日期:2009.5
5-Aryl-3,3,4,4-tetramethyl-3,4-dihydro-3H-pyrrol-2-imines,conformationally restrained 1,3-diazabuta-1,3-diene derivatives, were easily prepared by treating aryllithium species with 2,2,3,3-tetramethylsuccinonitrile (1). Trapping the reaction intermediate with chlorotrimethylsilane gave N-silylated compounds 2a–e, whereas aqueous workup gave N-H derivatives 3a,b. Pyrenyl-substituted compound 3b was
Palladium-Catalyzed Double Carbonylative Cyclization of Benzoins: Synthesis and Photoluminescence of Bis-Ester-Bridged Stilbenes
作者:Yosuke Tani、Takuji Ogawa
DOI:10.1021/acs.orglett.8b03169
日期:2018.12.7
bis-ester-bridged stilbenes just in two steps from aldehydes. Thus, the obtained fully fused tetracyclic π-systems have a pyrano[3,2-b]pyran-2,6-dione (PPD) core on their center, showing two reversible reductions at low potentials. In addition, their photoluminescence properties are strikingly affected by the aromatic ringsfused to the PPD core; bis-thieno-fused PPDs are found to be excellent fluorophores
已开发出钯催化的安息香双羰基双环化反应,该反应仅需两个步骤即可实现醛类双酯桥联的对苯二酚的合成。因此,获得的完全稠合的四环π系统在其中心具有吡喃并[3,2 - b ]吡喃-2,6-二酮(PPD)核,在低电势下显示出两个可逆的还原。另外,它们的光致发光特性受到与PPD核稠合的芳香环的显着影响。发现双噻吩并稠合的PPD是优异的荧光团,量子产率高达0.98。
Room-temperature phosphorescence-to-phosphorescence mechanochromism of a metal-free organic 1,2-diketone
An organic 1,2-diketone with intramolecular chalcogen bonding overcomes the room-temperature phosphorescence (RTP) quenching problem on amorphization, representing the first RTP-to-RTP mechanochromism of a metal-free organic molecule.