Dinuclear Palladium(III) Complexes with a Single Unsupported Bridging Halide Ligand: Reversible Formation from Mononuclear Palladium(II) or Palladium(IV) Precursors
作者:Julia R. Khusnutdinova、Nigam P. Rath、Liviu M. Mirica
DOI:10.1002/anie.201100928
日期:2011.6.6
Stable PdIII: Dinuclear PdIII complexes of the tridentate ligand trimethyltriazacyclononane (Me3tacn) were obtained by one‐electron oxidation of mononuclear PdII precursors. Further oxidation led reversibly to mononuclear PdIV species. The PdII and PdIII complexes are shown to be involved in the catalytic Kharasch addition of polyhaloalkanes to alkenes.
using the complexes generated in situ from a mixture of common copper(II) halides and the ligand. The photoelectrochemical properties of the copper(II)-quinoline complexes suggest their effective reduction by light-induced homolysis to form the corresponding active copper(I) species without the necessity of an external reducing agent. Excellent yields of regio- and stereoselective addition products (>20
合成了喹啉基配体的铜( II )配合物,并研究了它们在卤代烃与烯烃的原子转移自由基加成(ATRA)反应中的催化性能。在室温下的白光照射下,配合物有效地催化加成反应并抑制烯烃的自由基聚合。通过使用由普通卤化铜( II )和配体的混合物原位产生的配合物,可以方便地进行反应。铜( II )-喹啉配合物的光电化学性质表明它们通过光致均裂有效还原形成相应的活性铜( I) 不需要外部还原剂的物种。通过使用 1 mol% 或更少的催化剂,可以获得优异的区域和立体选择性加成产物(>20 个实例)。评估了常用添加剂 AIBN 和 Na 2 CO 3的作用,表明这些添加剂通过防止反应过程中 HX 的积累来减轻催化剂中毒。
Cycloruthenated complexes as homogeneous catalysts for atom-transfer radical additions
Various cycloruthenated complexes were used as homogeneous catalysts for the atom-transfer radical addition of polyhalogenated compounds to several olefinic substrates. Yields obtained through conventional or microwave heating could reach high values (up to 98% with CBrCl3 and 88% with CCl4). (c) 2009 Elsevier Ltd. All rights reserved.
Mononuclear Organometallic Pd(II), Pd(III), and Pd(IV) Complexes Stabilized by a Pyridinophane Ligand with a C-Donor Group
作者:Nicholas P. Ruhs、Julia R. Khusnutdinova、Nigam P. Rath、Liviu M. Mirica
DOI:10.1021/acs.organomet.9b00505
日期:2019.10.14
The (RN3CH)PdII(OAc)2 complexes contain a Cipso–H bond that remains unactivated at the PdII stage, even upon heating or addition of excess acetate. These PdII(OAc)2 complexes exhibit catalytic reactivity in the Kharasch radical addition of bromotrichloromethane to methyl methacrylate. Interestingly, novel PdIII complexes (RN3C)PdIIIBr2 were isolated from the Kharasch reaction mixture and have been
分离并鉴定了一系列带有修饰的四齿吡啶并吡啶并配体R N3CH的Pd配合物,它们含有一个C-供体苯基。(R N3CH)Pd II(OAc)2配合物包含一个C ipso -H键,即使在加热或添加过量的乙酸盐时,该键也未在Pd II阶段活化。这些Pd II(OAc)2配合物在溴三氯甲烷向甲基丙烯酸甲酯的Kharasch自由基加成中表现出催化反应活性。有趣的是,新型Pd III配合物(R N3C)Pd III Br 2分离自Kharasch反应混合物,并通过EPR,UV-可见光谱和X射线晶体学进行了表征,表明在Kharasch自由基加成的氧化条件下发生了C ipso -H键的活化。受此观察结果的启发,几种(pMe N3C)Pd III配合物是在用PhICl 2氧化Pd II前体并随后用th盐提取卤化物后合成的。此外,附加的单电子氧化生成可检测到的Pd IV物种,包括罕见的三阳离子[[ pMe N3C)Pd