56512-48-2Relevant articles and documents
Synthesis, Crystal Structures, and Solid-State Polymerization of 8?[4-(Dimethylamino)phenyl]octa-5,7-diynyl Carbamates
Ikeshima, Masataka,Katagiri, Hiroshi,Fujiwara, Wataru,Tokito, Shizuo,Okada, Shuji
, p. 5991 - 6000 (2018/09/27)
Six butadiyne monomers with (dimethylamino)phenyl and N-substituted urethane substituents were synthesized and their crystal structures and solid-state polymerization were investigated. In five of the six monomers, directions of the butadiyne stacking and
Synthesis and Simple Immobilization of Palladium(II) Acyclic Diaminocarbene Complexes on Polystyrene Support as Efficient Catalysts for Sonogashira and Suzuki-Miyaura Cross-Coupling
Mikhaylov, Vladimir N.,Sorokoumov, Viktor N.,Korvinson, Kirill A.,Novikov, Alexander S.,Balova, Irina A.
, p. 1684 - 1697 (2016/07/06)
Immobilization of palladium(II) acyclic diaminocarbene (Pd(II)-ADC) complexes on a resin support surface has been easily performed by metal-mediated addition of amino groups of benzhydrylamine-polystyrene to the coordinated isocyanide ligand of cis-PdCl2(CNR)2 (R = t-Bu, Cy). The investigation of the benzhydrylamine reaction with palladium-coordinated isocyanides in solution has revealed that, depending on the reaction conditions, two carbene-type complexes can be obtained as a result of the addition to the CN triple bond, as well as a third complex which is formed via substitution of the isocyanide ligand by benzhydrylamine. Nucleophilic addition of an amino group to the isocyanide ligand has led to a cis-acyclic diaminocarbene complex or a cationic diaminocarbene complex with trans configuration and an intramolecular hydrogen-bonded chloride anion (the nature of this noncovalent interaction was analyzed by DFT calculations, including AIM analysis). The unsupported and resin-supported palladium catalysts have demonstrated high catalytic activity in both Sonogashira and Suzuki-Miyaura cross-coupling. The supported catalyst can be recovered and repeatedly reused without a significant loss in efficiency. The degree of the palladium binding with polystyrene, the oxidation state, and the palladium leaching level were investigated by XPS and XRF analyses.
Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions
Caporale, Andrea,Tartaggia, Stefano,Castellin, Andrea,De Lucchi, Ottorino
supporting information, p. 384 - 393 (2014/03/21)
Two efficient protocols for the palladium-catalyzed synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides in the absence of copper were developed. A simple catalytic system consisting of Pd(OAc)2 and P(p-tol)3 using DBU as the base and THF as the solvent was found to be highly effective for the coupling reaction of 2-methyl-3-butyn-2-ol (4) with a wide range of aryl bromides in good to excellent yields. Analogously, the synthesis of aryl-2-methyl-3-butyn-2-ols was performed also through the decarboxylative coupling reaction of 4-hydroxy-4-methyl-2-pentynoic acid with aryl bromides, using a catalyst containing Pd(OAc)2 in combination with SPhos or XPhos in the presence of tetra-n-butylammonium fluoride (TBAF) as the base and THF as the solvent. Therefore, new efficient approaches to the synthesis of terminal acetylenes from widely available aryl bromides rather than expensive iodides and using 4 or propiolic acid rather than TMS-acetylene as inexpensive alkyne sources are described.
