1519-59-1Relevant articles and documents
Phosphorescent platinum(II) complexes bearing 2-vinylpyridine-type ligands: Synthesis, electrochemical and photophysical properties, and tuning of electrophosphorescent behavior by main-group moieties
Yang, Xiaolong,Xu, Xianbin,Zhao, Jiang,Dang, Jing-Shuang,Huang, Zuan,Yan, Xiaogang,Zhou, Guijiang,Wang, Dongdong
, p. 12986 - 13000 (2014)
A series of 2-vinylpyridine-type platinum(II) complexes bearing different main-group blocks (B(Mes)2, SiPh3, GePh3, NPh2, POPh2, OPh, SPh, and SO2Ph, where Mes = 2-morpholinoethanesulfonic acid) were successfully prepared. As indicated by the X-ray single-crystal diffraction, the concerned phosphorescent platinum(II) complexes exhibit distinct molecular packing patterns in the solid state to bring forth different interactions between individual molecules. The photophysical characterizations showed that the emission maxima together with phosphorescent quantum yield of these complexes can also be affected by introducing distinct main-group moieties with electron-donating or electron-withdrawing characters. Furthermore, these 2-vinylpyridine-type platinum(II) complexes exhibit markedly different photophysical and electrochemical properties compared with their 2-phenylpyridine-type analogues, such as higher-lying highest occupied molecular orbital levels and lower-energy phosphorescent emissions. Importantly, these complexes can show good potential as deep red phosphorescent emitters to bring attractive electroluminescent performances with Commission Internationale de L'Eclairage (CIE) coordinates very close to the standard red CIE coordinates of (0.67, 0.33) recommended by the National Television Standards Committee. Hence, these results successfully established structure-property relationship concerning photophysics, electrochemistry, and electroluminescence, which will not only provide important information about the optoelectronic features of these novel complexes but also give valuable clues for developing novel platinum(II) phosphorescent complexes.
Heterobimetallic Pd/Mn and Pd/Co complexes as efficient and stereoselective catalysts for sequential Cu-free Sonogashira coupling–alkyne semi-hydrogenation reactions
Baweja, Saral,Clauss, Reike,Gelman, Dmitri,Hey-Hawkins, Evamarie
supporting information, p. 1344 - 1356 (2022/02/03)
A series of heterobimetallic PdII/MII complexes (MII = Mn, Co) were synthesised and tested as precatalysts for sequential Sonogashira coupling–alkyne semi-hydrogenation reactions to form Z-aryl alkenes. The carbometalated heterobimetallic PdII/CoII complex CoPdL3′ demonstrated an apparent cooperative effect compared to the corresponding monometallic counterparts. This compound was identified as a potent single-molecule catalyst for the one-pot Cu-free Sonogashira coupling of aryl bromides with terminal alkynes followed by chemo- and stereoselective semi-hydrogenation of the alkyne intermediate using NH3·BH3 as a hydrogen source. Furthermore, different aromatic substrates have been tested to show the generality of the reaction for the synthesis of Z-alkenes, including biologically active combretastatin A-4. In addition, the homogeneous nature of the catalytically active species was demonstrated.
Copper(0) nanoparticle catalyzed Z-Selective Transfer Semihydrogenation of Internal Alkynes
Moran, Maria Jesus,Martina, Katia,Bieliunas, Vidmantas,Baricco, Francesca,Tagliapietra, Silvia,Berlier, Gloria,De Borggraeve, Wim M.,Cravotto, Giancarlo
, p. 2850 - 2860 (2021/05/06)
The use of copper(0) nanoparticles in the transfer semihydrogenation of alkynes has been investigated as a lead-free alternative to Lindlar catalysts. A stereo-selective methodology for the hydrogenation of internal alkynes to the corresponding (Z)-alkenes in high isolated yields (86% average) has been developed. This green and sustainable transfer hydrogenation protocol relies on non-noble copper nanoparticles for reduction of both electron-rich and electron-deficient, aliphatic-substituted and aromatic- substituted internal alkynes. Polyols, such as ethylene glycol and glycerol, have been proven to act as hydrogen sources, and excellent stereo- and chemoselectivity have been observed. Enabling technologies, such as microwave and ultrasound irradiation are shown to enhance heat and mass transfer, whether used alone or in combination, resulting in a decrease in reaction time from hours to minutes. (Figure presented.).
Role of Benzylic Deprotonation in Nickel-Catalyzed Benzylic Dehydrogenation
Zhang, Pengpeng,Cantrell, Rachel L.,Newhouse, Timothy R.
supporting information, p. 1652 - 1656 (2021/07/31)
Alkylarenes are readily functionalized via the corresponding benzylic anions. Benzylic anions have been used for a range of catalytic reactions, including Ni-catalyzed dehydrogenation. Interestingly, the employment of Zn(TMP) 2for slow and incomplete deprotonation of the benzylic position was observed. This manuscript describes a preliminary investigation into the deprotonation of heteroarenes and its relationship to Ni-catalyzed benzylic dehydrogenation.
