carbenes led to the formation of kinetically unstable mono‐adducts, one of which was structurally characterized. A comparison of the NMR spectra and structural data of new and literature‐known bis‐adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed.
通过与高灵敏度的B 2 X 4前体(X = Cl,Br,I)直接形成加合物,合成了一系列22种新的双(膦),双(卡宾)和双(异腈)四卤代二硼烷加合物。稳定的B 2 X 4(SMe 2)2前体(X = Cl,Br)与不稳定的二甲基硫醚配体进行配体交换。使用NMR光谱,元素分析已对分离出的化合物进行了充分表征,对于其中的20种化合物,还进行了单晶X射线衍射分析,结果发现键基序发生了意想不到的变化。除了经典的B 2 X 4 L 2diborane(4)双加合物,某些对空间要求更高的卡宾配体诱导卤化物置换,从而导致第一个卤化物桥联的单阳离子二硼物种[B 2 X 3 L 2 ] A(A = BCl 4,Br,I)。此外,B 2 Cl 4与空间上需要的N-杂环卡宾的低温1:1反应导致形成动力学不稳定的单加合物,其中之一具有结构特征。对新的和文献已知的双加合物的NMR光谱和结构数据进行的比较显示出一些与
Synthesis and electrochemistry of late transition metal complexes containing 1,1′-bis(dicyclohexylphosphino)ferrocene (dcpf). The X-ray structure of [PdCl2(dcpf)] and Buchwald–Hartwig catalysis using [PdCl2(bisphosphinometallocene)] precursors
作者:Laura E. Hagopian、Alison N. Campbell、James A. Golen、Arnold L. Rheingold、Chip Nataro
DOI:10.1016/j.jorganchem.2006.08.030
日期:2006.11
electrochemistry of 1,1′-bis(dicyclohexylylphosphino)ferrocene (dcpf) was examined in methylene chloride with tetrabutylammonium hexafluorophosphate or tetrabutylammonium tetrakis(pentafluorophenyl)borate as the supporting electrolyte. The oxidation of dcpf is complicated by a follow-up reaction. Seven new complexes containing dcpf and one new compound containing 1,1′-bis(di-tert-butylphosphino)ferrocene (dtbpf)
A Broadly Applicable Strategy for Entry into Homogeneous Nickel(0) Catalysts from Air-Stable Nickel(II) Complexes
作者:Eric A. Standley、Stacey J. Smith、Peter Müller、Timothy F. Jamison
DOI:10.1021/om500156q
日期:2014.4.28
A series of air-stable nickel complexes of the form L2Ni(aryl) X (L = monodentate phosphine, X = Cl, Br) and LNi(aryl)X (L = bis-phosphine) have been synthesized and are presented as a library of precatalysts suitable for a wide variety of nickel-catalyzed transformations. These complexes are easily synthesized from low-cost NiCl2·6H2O or NiBr2·3H2O and the desired ligand followed by addition of 1
已经合成了一系列 L 2 Ni(芳基)X(L = 单齿膦,X = Cl,Br)和 LNi(芳基)X(L = 双膦)形式的空气稳定镍配合物,并表示为适用于各种镍催化转化的预催化剂库。这些配合物很容易由低成本的 NiCl 2 ·6H 2 O 或 NiBr 2 ·3H 2合成O 和所需的配体,然后加入 1 当量的格氏试剂。选择的这些配合物通过单晶 X 射线衍射进行了表征,并提供了对其结构特征的分析。介绍了将它们用作镍催化羰基-烯反应的预催化剂的案例研究,与使用 Ni(cod) 2 的反应相比,显示出优异的反应性。此外,由于预催化剂都对空气稳定,因此不需要手套箱或惰性气氛技术来利用这些配合物进行镍催化反应。
Bis(dialkylphosphino)ferrocene-Ligated Nickel(II) Precatalysts for Suzuki–Miyaura Reactions of Aryl Carbonates
作者:Emily L. Barth、Ryan M. Davis、Megan Mohadjer Beromi、Andrew G. Walden、David Balcells、Gary W. Brudvig、Amira H. Dardir、Nilay Hazari、Hannah M. C. Lant、Brandon Q. Mercado、Ian L. Peczak
DOI:10.1021/acs.organomet.9b00543
日期:2019.9.9
(dcypf)Ni(2-ethylphenyl)(Br), which contains a bidentate phosphine that binds in a trans geometry, is an effective precatalyst for these reactions for two reasons: (i) it rapidly forms the Ni(0) active species and (ii) it minimizes comproportionation reactions between the Ni(0) active species and both the unactivated Ni(II) precatalyst and on-cycle Ni(II) complexes to form catalytically inactive Ni(I)
Organometallic Fe-Fe Interactions: Beyond Common Metal-Metal Bonds and Inverse Mixed-Valent Charge Transfer
作者:Mark R. Ringenberg、Max Schwilk、Florian Wittkamp、Ulf-Peter Apfel、Wolfgang Kaim
DOI:10.1002/chem.201605527
日期:2017.2.3
the mixed‐valent monocations are due to an unprecedented “inverse” inter‐valence charge transfer from the electron‐rich iron(II) in the ferrocene backbone to the electron‐deficient tricarbonyliron(I). Protonation of complex 1 results in the formation of the structurally characterized hydride [1H]BF4, which reacts with acetone to form the dication, 12+, and isopropanol. While the hydride [2H]BF4 was found
化合物[Fe(CO)3(dRpf)] n +,n = 0,1,2和dRpf = 1,1'-双(二环己基膦基)二茂铁([ 1 ] n +)或1,1'-bis(二异丙基膦基)二茂铁([ 2 ] n +)是通过光解和氧化还原反应获得的两步可逆氧化还原系统。铁-铁的距离在氧化时从大约4Å减少到大约3Å,氧化主要发生在三羰基铁部分。尽管计算出二茂铁的氧化仅在激发态下发生,但混合价单阳离子的近红外吸收是由于前所未有的“逆”价电荷从二茂铁主链中的富电子铁(II)转移至二价铁而形成的。缺电子的三羰基铁(I)。配合物1的质子化导致结构上表征的氢化物[ 1 H] BF 4形成,该氢化物与丙酮反应形成二价离子1 2+和异丙醇。而氢化物[发现2 H] BF 4不稳定,丙酮中2的质子化导致2 2+的干净形成,形式上为氢转移。