Synthesis, Reactivity, and Electrochemical Studies of Gold(I) and Gold(III) Complexes Supported by <i>N</i>-Heterocyclic Carbenes and Their Application in Catalysis
作者:Marek Pažický、Annette Loos、Maria João Ferreira、Daniel Serra、Nikolai Vinokurov、Frank Rominger、Christoph Jäkel、A. Stephen K. Hashmi、Michael Limbach
DOI:10.1021/om1005484
日期:2010.10.25
cleanly oxidized to the corresponding Au(III) complexes with phenyliodoso dichloride, as are the corresponding halide Au(I) complexes. The attempted salt metathesis with the parent Au(III) complex led to the oxidative coupling of the aryl residues with formation of the Au(I) complex. Some of the complexes are promising catalysts in the cycloisomerization of an ω-alkynylfuran to isobenzofuranol in the
Palladium-catalyzed aminations of aryl halides with phosphine-functionalized imidazolium ligands
作者:Ji-cheng Shi、Pengyu Yang、Qingsong Tong、Li Jia
DOI:10.1039/b714892e
日期:——
110 degrees C, and 94% of conversion was afforded with the less sterical demanding 1a for a longer time. However, for the substrates with ortho-substituents, higher conversions were achieved with 1a. The Pd(OAc)2/1d catalytic system was also active for deactivated aryl chloride, and 71% isolated yield for the desired product was realized for coupling of 4-chloroanisole with morpholine at 2 mol% of catalyst
一系列的1-(2-二苯基膦基二茂铁基)乙基-3-取代的碘化咪唑鎓碘化物[3-取代基=甲基(1a); 异丙基(1b);叔丁基(1c); 1-腺苷(1d); 环己基(1e); 2,6-二甲基苯基(1f); 2,4,6-三甲基苯基(1g); 已经制备了2,6-二异丙基苯基(1h)],并作为钯在芳基卤化物与各种胺的胺化反应中的配体进行了评估。偶联过程的范围是对各种芳基溴化物和氯化物进行的,催化剂是由Pd(OAc)2的混合物在碱的存在下原位生成的。尽管NaOH或Cs2CO3以中等转化率促进了4-溴甲苯与吗啉的偶联,但发现NaO t Bu是与二恶烷,甲苯或DME组合的碱的选择。发现杂二齿螯合体系中咪唑的3-取代基的空间位阻仅对没有邻取代基的底物有利。受空间位阻较大的1d或1h在110°C的NaO t Bu存在下以0.2 mol%的钯负载量以几乎定量的转化率促进了溴苯与吗啉的偶合,而对空间要求较低的1a
Bridged Imidazolium Salts Used as Precursors for Chelating Carbene Complexes of Palladium in the Mizoroki-Heck Reaction
A variety of chiral and achiral imidazoliumsalts is synthesized. Methylene-, ethylene-, propylene- and pyridinyl-bridged bis(imidazolium) halides are used to generate the respective free chelating carbenes. The synthesis of palladium complexes of general formula [cis-CH 2 NC(H)=C(H)N(R)C} 2 PdX 2 ] with these chelating N-heterocyclic carbene ligands is reported. Structural proofs of complexes 28
Unsymmetric-1,3-disubstituted imidazolium salt for palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl bromides
作者:Hong-Wei Yu、Ji-Cheng Shi、Hong Zhang、Peng-Yu Yang、Xin-Ping Wang、Zi-Lin Jin
DOI:10.1016/j.molcata.2006.01.034
日期:2006.5
ferrocenylethyl acetate and the corresponding N-substituted imidazole in high yields (70–94%). A combination of Pd(OAc)2 and 1a–d was found to form an excellent catalyst system for the Suzuki–Miyaura cross-couplingreactions of aryl bromides with phenylboronic acid in the presence of Cs2CO3.
一系列的1-(ferrocenylethyl)-3-取代的咪唑鎓盐[3-替代= 2,6-二(异-丙基)苯基(1A),2,4,6-三甲基苯基(1B),叔丁基(1c),1-Ad(1d),环己基(1e)]是由外消旋二茂铁乙酸乙酯和相应的N-取代的咪唑合成的,产率很高(70-94%)。发现Pd(OAc)2和1a - d的组合形成了一个极好的催化剂体系,用于在Cs 2 CO 3存在下芳基溴化物与苯硼酸的Suzuki-Miyaura交叉偶联反应。
Synthesis and Characterization of Gold(I) Complexes of Dibenzotropylidene-Functionalized NHC Ligands (Trop-NHCs)
作者:Marcel Brill、Alba Collado、David B. Cordes、Alexandra M. Z. Slawin、Matthias Vogt、Hansjörg Grützmacher、Steven P. Nolan
DOI:10.1021/om501093s
日期:2015.1.12
ligands (Trop-NHCs) have been prepared in order to investigate their structural features and to reveal possible interactions of the olefin unit with the metal center. The precursor imidazolium chloride salts (R-1) were generated in a single step using N-substituted imidazoles (R = H, Me, DiPP, Ad) and 1 or 2 equiv of Trop-Cl, generating unsymmetrical and symmetrical NHC-olefin hybrids. The structural parameters