(N-Arylaminomethyl)pyridine-N-oxides: Synthesis and characterization of potential ligand systems and the formation of their N,O-chelate aluminum complexes
摘要:
Pyridine-N-oxide-2-carbaldehyde (4a) was converted to the corresponding imine (5a) by treatment with 2,6-diisopropylaniline. Subsequent reduction with a sodium borohydride gave the corresponding ( N-arylaminomethyl) pyridine-N-oxide derivative (6a). A series of analogous compounds was prepared starting from the respective ( aldimino) quinoline-N-oxide ( 4b) or ( ketimino) pyridine-N-oxide ( 10) systems. Deprotonation of the ( aminomethyl) pyridine-N-oxides resulted in a series of unexpected reactions, such as coupling, internal redox reactions or fragmentation. Eventually, the N,O-chelate aluminum complexes ( 22, 23) derived from the ( aminoethyl) pyridine-N-oxide ligand systems could be obtained by treatment of the respective iminopyridine-N-oxides with trimethylaluminum. Many products were characterized by X-ray diffraction. (C) 2008 Elsevier B. V. All rights reserved.
The ‘one-pot’ syntheses of α,α′-diphosphino-substituted imines: a unique reaction of bulky bis(dialkylamino)chlorophosphines
作者:Antoine Baceiredo、Guy Bertrand、Philip W. Dyer、John Fawcett、Nina Griep-Raming、Olivier Guerret、Martin J. Hanton、David R. Russell、Anna-Maria Williamson
DOI:10.1039/b009867l
日期:——
The reaction between various bis(dialkylamino)chlorophosphines and N-isopropyl-substituted lithium amides afforded bis(α,α′-phosphino)imines in a ‘one-pot’ procedure. These compounds react with sulfur to generate intramolecularly hydrogen-bonded ylide derivatives. The molecular structure of (Pr2iN)2PCH2C(NBut)CH2P(NPri)2 has been determined by X-ray crystallography.
Nickel and palladium phosphinimine-imine ligand complexes
作者:Jason D. Masuda、Pingrong Wei、Douglas W. Stephan
DOI:10.1039/b306110h
日期:——
The imine (C6H3i-Pr2)NCMe21 was prepared and used to make the phosphine (C6H3i-Pr2)NC(Me)CH2PPh22. Oxidation with the substituted arylazide resulted in the isolation of the phosphinimine-imine species (C6H3i-Pr2)NC(Me)CH2PPh2(NC6H3i-Pr2)
3. The ligand 3 forms the neutral Ni-complex NiBr2((C6H3i-Pr2)NC(Me)CH2PPh2(NC6H3i-Pr2))
4 while attempts to prepare the analogous Pd species were unsuccessful. Reaction of 3 with n-BuLi produced the Li-salt Li(thf)((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2))
5. Subsequent reaction with NiBr2(dme) afforded [Ni((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2))(μ-Br)2Li(thf)2]
6. In related syntheses 5 reacted with NiBr2(dme) or (PhCN)2PdCl2 and PPh3 to give the complexes of formulation MX((C6H3i-Pr2)NC(Me)CHPPh2(NC6H3i-Pr2))(PPh3)
(X = Br, M = Ni 7; X = Cl, M = Pd 8). The latter complexes 7 and 8 are phosphinimine-N–C bound. Structural studies of 2 and 4–8 are reported. The implications of these studies for the utility of this phosphinimine-imine ligand in olefin polymerization catalysts are considered.
Alkali Metal Amide Salts of a Bulky Nitrogen Tethered Phosphonium Fluorenide Ligand
作者:Tanner George、Jason D. Masuda
DOI:10.1021/acs.organomet.3c00204
日期:2023.9.11
0.5(THF, n-hexane) solvate of 3 occur as the (Z)-enamine, while co-crystallization of either diethyl ether or 3 molecules of THF resulted in the (E)-enamine of 3. The ability for compound 3 to participate in two types of hydrogen bonds between either the methyne or amine protons with THF was observed from the 0.5(THF, n-hexane) and 3(THF) solvates, respectively. Subsequent deprotonation of the secondary
先前报道的膦-亚胺配体与9-溴芴的反应提供了溴化鏻(E)-烯胺,其在去质子化后提供了与氟化鏻部分相连的烯胺。分离该烯胺的各种晶体并随后通过单晶X射线衍射分析表明存在(E)-和(Z)-异构体,这由C 6 D 6 中的三种动态异构体支持。1 H NMR 光谱表明,烯胺鏻氟化物是主要异构体,并且在3的所有四种固态晶体结构中也观察到。无溶剂的3和3的0.5(THF,正己烷)溶剂化物以 (Z)-烯胺的形式出现,而乙醚或 3 分子 THF 的共结晶产生3的 (E)-烯胺。化合物3参与次甲基或胺质子与 THF 之间两种类型氢键的能力分别从 0.5(THF,正己烷)和 3(THF)溶剂合物中观察到。随后用含锂、钠和钾的碱对仲胺进行去质子化,产生金属酰胺,主要形成单体结构。每种碱金属均由一个配体与配位溶剂分子 (Et 2O或THF),唯一的例外是缺乏配位溶剂的钾络合物。该钾络合物的供体空位通过与相邻 6 元
Hexacoordinated tin complexes catalyse imine hydrogenation with H2
作者:Andrea Žáková、Pritha Saha、Alexandros Paparakis、Martin Zábranský、Gabriela Gastelu、Jaroslav Kukla、Jorge G. Uranga、Martin Hulla
DOI:10.1039/d3cc05878f
日期:——
that hexacoordinated tin complexes with Schiff base ligands catalyse imine hydrogenation via activation of H2(g). As shown by hydrogen–deuterium scrambling, [Sn(tBu2Salen)(OTf)2] activated H2(g) at 25 °C and 10 bar of H2. After tuning the ligands, we found that [Sn(Salen)Cl2] was the most efficient imine hydrogenation catalyst despite having the lowest activity in H2(g) activation. Moreover, various imines
受阻路易斯对(FLP)加氢催化剂主要使用烷基和芳基取代的路易斯酸(LA),它们提供有限数量的取代基组合,限制了我们调节其性质并最终调节其反应性的能力。尽管如此,主族配合物有许多可用于此类目的的配体,这可以使我们扩大 FLP 催化的范围。为了支持这一假设,我们在此证明了具有希夫碱配体的六配位锡络合物通过活化 H 2(g) 来催化亚胺氢化。如氢-氘加扰所示,[Sn( t Bu 2 Salen)(OTf) 2 ] 在 25 °C 和 10 bar 的 H 2下活化了 H 2(g) 。调整配体后,我们发现[Sn(Salen)Cl 2 ]是最有效的亚胺氢化催化剂,尽管其在H 2(g)活化中的活性最低。此外,各种亚胺的氢化收率高达98%,从而为开发基于主族元素六配位LA的新型FLP氢化催化剂提供了机会。
Rich C–H bond activations of yttrium alkyl complexes bearing phosphinimino-amine ligands
作者:Danfeng Li、Shihui Li、Dongmei Cui、Xuequan Zhang
DOI:10.1016/j.jorganchem.2010.09.005
日期:2010.12
Aseries of phosphinimino-amine compounds (2,6-iPr(2)-C6H3NH)C(Me)CHPPh2(NAr)(Ar = 2,6-iPr(2)-C6H3 (HL1),2,6-Et-2-C6H3 (HL2),2,6-Me-2-C6H3 (HL3), C6H5 (HL4), 3-CF3-C6H4 (HL5)) that existed in imine and amine forms were synthesized and fully characterized. Treatment of HL1-5 with Y(CH2SiMe3)(3)(THF)(2) afforded the corresponding yttrium mono- or bis(alkyl) complexes that depended significantly on the ancillary ligands. The reactions between HL1-3 and Y(CH2SiMe3)(3)(THF)(2) at room temperature generated mononuclear monoalkyl complexes 1-3 via deprotonation and C-H bond activation. However, when compounds HL4,5 were used, the dialkyl complexes 4 and 5 were isolated by deprotonation only. The molecular structures of complexes 1-4 were characterized with X-ray crystallography and discussed. (c) 2010 Elsevier B.V. All rights reserved.