半夹心结构含1, 2-二硒碳硼烷的多核Co配合物的合成及结构表征

在氩气保护下,以邻位-碳硼烷、正丁基锂、硒粉和CpCo（CO）I₂为起始原料,合成、分离得到配合物CpCo（Se₂C₂B₁₀H₁₀）（1）、（CpCo）₂（Se₂C₂B₁₀H₁₀）（2）和（CpCo）₄（μ₃-Se）₄Co₂（μ₃-Se₂C₂B₁₀H₁₀）₄Co·CH₂Cl₂（3）,并用元素分析、质谱、IR、¹H NMR及X-射线单晶衍射对配合物（3）进行了表征。晶体属正交晶系,空间群P2₁2₁2₁,其晶胞参数为：a=1.30720（13）nm,b=1.39137（11）nm,c=3.88533（15）nm,β=90°,Z=4,V=7.0666（9）nm³,μ=7.890mm^-1,D_c=2.138g·cm^-3,F（000）=4268,R₁=0.0543,wR₂=0.1363。配合物中4个（Se₂C₂B₁₀H₁₀）^2-配体和4个单硒基团形成了1个Co₇Se₁₂核。     

半夹心结构含1,2-二硒碳硼烷的多核Co配合物的合成及结构表征

在氩气保护下,以邻位-碳硼烷、正丁基锂、硒粉和CpCo(CO)I2为起始原料,合成、分离得到配合物CpCo(Se2C2B10H10)(1)、(CpCo)2(Se2C2B10H10)(2)和(CpCo)4(μ3-Se)4Co2(μ3-Se2C2B10H10)4Co·CH2Cl2(3),并用元素分析、质谱、IR、1H NMR及X-射线单晶衍射对配合物(3)进行了表征。晶体属正交晶系,空间群P212121,其晶胞参数为:a=1.307 20(13)nm,b=1.391 37(11)nm,c=3.885 33(15)nm,β=90°,Z=4,V=7.066 6(9)nm3,μ=7.890 mm-1,Dc=2.138 g·cm-3,F(000)=4 268,R1=0.054 3,wR2=0.136 3。配合物中4个(Se2C2B10H10)2-配体和4个单硒基团形成了1个Co7Se12核。     

A stable cation of a CSi3P five-membered ring with a weakly coordinating chloride anion

Don't count on counterions: The cyclic five-membered CSi(3)P cation 1 is synthesized in the reaction of benzamidinato-stabilized chlorosilylene and methyl phosphaalkyne. The presence of four π?electrons in 1 means it can be considered as a formal, heavier analogue of the cyclopentadienyl cation. Surprisingly the small counteranion (Cl(-)) does not contribute to the ring stability.     

Metalloradical Cations and Dications Based on Divinyldiphosphene and Divinyldiarsene Ligands

Metalloradicals are key species in synthesis, catalysis, and bioinorganic chemistry. Herein, two iron radical cation complexes ( 3-E )GaCl₄ [( 3-E )^.+ = [{(IPr)C(Ph)E}₂Fe(CO)₃]^.+, E = P or As; IPr = C{(NDipp)CH}₂, Dipp = 2,6-iPr₂C₆H₃] are reported as crystalline solids. Treatment of the divinyldipnictenes {(IPr)C(Ph)E}₂ ( 1-E ) with Fe₂(CO)₉ affords [{(IPr)C(Ph)E}₂Fe(CO)₃] ( 2-E ), in which 1-E binds to the Fe atom in an allylic (η³-EEC_vinyl) fashion and functions as a 4e donor ligand. Complexes 2-E undergo 1e oxidation with GaCl₃ to yield ( 3-E )GaCl₄. Spin density analysis revealed that the unpaired electron in ( 3-E )^.+ is mainly located on the Fe (52–64 %) and vinylic C (30–36 %) atoms. Further 1e oxidation of ( 3-E )GaCl₄ leads to unprecedented η³-EEC_vinyl to η³-EC_vinylC_Ph coordination shuttling to form the dications ( 4-E )(GaCl₄)₂.     

Iron‐ and Cobalt‐Catalyzed Synthesis of Carbene Phosphinidenes

In the presence of stoichiometric or catalytic amounts of [M{N(SiMe₃)₂}₂] (M=Fe, Co), N‐heterocyclic carbenes (NHCs) react with primary phosphines to give a series of carbene phosphinidenes of the type (NHC)?PAr. The formation of (IMe₄)?PMes (Mes=mesityl) is also catalyzed by the phosphinidene‐bridged complex [(IMe₄)₂Fe(μ‐PMes)]₂, which provides evidence for metal‐catalyzed phosphinidene transfer.     

Iron‐ and Cobalt‐Catalyzed Asymmetric Hydrosilylation of Ketones and Enones with Bis(oxazolinylphenyl)amine Ligands

Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.     

Synthesis and Crystal Structure of a New Mononuclear Cobalt(Ⅲ) Complex with 2,2′-Dipyridylamine and Glycine as Ligands

A new mononuclear cobalt(III) complex [Co(dpa)2(Gly)](ClO4)2′4H2O was synthesized by the reaction of Co2+, glycine (gly) and 2,2′-dipyridylamine (dpa) in a methanol-water solution, and its structure was characterized by IR, EA, ES-MS and X-ray structure analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8795(2), b = 13.2904(2), c = 19.1104(2) , β = 109.378(1)°, V = 3085.89(8) 3, Z = 4, Mr = 746.36, Dc = 1.606 g/cm3, μ = 0.808 mm-1, F(000) = 1536, the final R = 0.0543 and wR = 0.1306 for 5393 independent reflections. The magnetic measurement of the compound at room temperature shows that it is diamagnetic and the cobalt ion is in low spin +3 oxidation state. ES-MS experiments show that the [Co(dpa)2(Gly)]2+ cation is very stable in the methanol solution.     

Metal-Assisted Opening of Intact P4 Tetrahedra

The reactivity of ruthenium and manganese complexes bearing intact white phosphorus in the coordination sphere was investigated towards the low-valent transition-metal species [Cp′′′Co] (Cp′′′=η⁵-C₅H₂-1,2,4-tBu₃) and [L⁰M] (L⁰=CH[CHN(2,6-Me₂C₆H₃)]₂; M=Fe, Co). Remarkably, and irrespective of the metal species, the reaction proceeds by the selective cleavage of two P–P edges and the formation of a square-planar cyclo-P₄ ligand. The reaction products [{CpRu(PPh₃)₂}{CoCp′′′}(μ,η^1:4-P₄)][CF₃SO₃] ( 5 ), [{Cp^BIGMn(CO)₂}₂{CoCp′′′}(μ,η^1:1:4-P₄)] ( 6 ) and [{Cp^BIGMn(CO)₂}₂{ML⁰}(μ,η^1:1:4-P₄)] (Cp^BIG=C₅(C₆H₄nBu)₅; L⁰=CH[CHN(2,6-Me₂C₆H₃)]₂; M=Fe ( 7 a ), Co ( 7 b )), respectively, were fully characterized by single-crystal X-ray diffraction and spectroscopic methods. The electronic structure of the cyclo-P₄ ligand in the complexes 5 – 7 is best described as a π-delocalized P₄²⁻ system, which is further stabilized by two and three metal moieties, respectively. DFT calculations envisaged a potential intermediate in the reaction to form 5 , in which a quasi-butterfly-shaped P₄ moiety bridges the two metals and behaves as an η³-coordinated ligand towards the cobalt center.     

Ternary cobalt-iron phosphide nanocrystals with controlled compositions, properties, and morphologies from nanorods and nanorice to split nanostructures

Structural phase-controlled formation of binary Co(2)P and CoP nanocrystals is achieved by reacting cobalt(II) oleate with trioctylphosphine. In the absence of oleylamine, Co(2)P nanowires are formed at both 290 and 320 °C. In the presence of oleylamine, Co(2)P nanorods are formed at 290 °C, and CoP nanorods are formed at 320 °C. With the simultaneous reaction of iron(III) oleate and cobalt(II) oleate with trioctylphosphine in the presence of oleylamine, ternary Co(2)P-type cobalt-iron phosphide nanostructures are produced at both 290 and 320 °C, corresponding to rice-shaped Co(1.5)Fe(0.5)P nanorods and split Co(1.7)Fe(0.3)P nanostructures, respectively. The controlled incorporation of iron into cobalt phosphide can alter the magnetic properties from paramagnetic binary Co(2)P to ferromagnetic Co(2)P-type ternary cobalt-iron phosphide nanostructures. Meanwhile, the time-dependent morphological evolution from small nanodots/nanorods, through seeded growth to unique split nanostructures is demonstrated in one-pot reaction at 320 °C.     

含碳硼烷半夹心型钴硫16电子化合物与二炔烃的反应性研究

含双硫取代碳硼烷二齿配体的半夹心型钴16电子化合物CpCo[S2C2(B10H10)](Co16e)分别与1,4-二乙炔基苯(L1)、(S)-2,2′-二乙酰氧基-6,6′-二乙炔基-1,1′-联萘(L2)、2-溴-5-乙炔基噻吩(L3)和2,5-二乙炔基噻吩(L4)反应,分别得到18电子单核化合物CpCo(S2C2B10H9)(H2CCPhC≡CH)(1),CpCo(S2C2B10H9)[H2CC(C24H16O4)C≡CH](2),CpCo(S2C2B10H9)[H2CC(C4H2S)Br](3),和CpCo(S2C2B10H9)[H2CC(C4H2S)C≡CH](4)。化合物1～4的结构中都发生了金属诱导B-H键活化并生成了新的C-B键。在Co16e与L4的反应中,还得到了两分子炔烃以头对头二聚插入到金属中心的18电子化合物CpCo(S2C2B10H9)[HC≡C(C4H2S)C=CH-CH=C(C4H2S)C≡CH](5)。上述化合物通过NMR、IR、MS、元素分析等方法进行表征。     

Reactions of 16e CpCo half-sandwich complexes containing a chelating 1,2-dicarba-closo-dodecaborane-1,2-dichalcogenolate ligand with ethynylferrocene and dimethyl acetylenedicarboxylate

The reaction of the 16e half-sandwich complex [CpCo(S2C2B10H10)] (1S; Cp: cyclopentadienyl) with ethynylferrocene in CH2Cl2 at ambient temperature leads to [CpCo(S2C2B10H9)-(CH2CFc)] (2S; Fc: ferrocenyl) and 1,2,4-triferrocenylbenzene. In 2S, B substitution occurs at the carborane cage in the position B3/B6 with the formation of a C-B bond. In the presence of the protic solvent MeOH, 2S loses a CpCo fragment to generate [(CH2CFc)(S2C2B10H9)] (3S). On the other hand, 2S can take a free CpCo fragment to form [(CpCo)2(S2C2B9H8)-(CHCFc)] (4S) containing a nido-C2B9 unit. In sharp contrast, [CpCo-(Se2C2B10H10)] (1Se) does not react with the alkyne in CH2Cl2, but in MeOH [(CHCFc)(Se2C2B10H10)] (5Se) is generated without the presence of a CpCo unit. The reaction of 1 with dimethyl acetylenedicarboxylate at ambient temperature leads to insertion compounds [CpCo(E2C2B10H10){(MeO2C)-C=C(CO2Me)}] (6S, E=S; 6 Se, E=Se). Upon heating, 6S rearranges to two geometrical isomers [CpCo(S2C2B10H9){(MeO2C)C=CH(CO2Me)}] (7S) and [CpCo(S2C2B10H9){(MeO2C)-CHC(CO2Me)}] (8S). In both, B-H functionalization takes place at the carborane cage in the position B3/B6, but 7S is a 16e complex with an olefinic unit in a Z configuration, and 8S is an 18e complex containing an alkyl B-CH group. Further treatment of 7 S with dimethyl acetylenedicarboxylate at ambient temperature affords two B-disubstituted complexes at the carborane cage in the positions of the B3 and B6 sites, that is, [CpCo(S2C2-B10H8){(MeO2C)C=CH(CO2Me)}2] (9S) and [CpCo(S2C2B10H8){(MeO2C)-CHC(CO2Me)}{(MeO2C)C=CH-(CO2Me)}] (10S). Compound 9S is a 16e complex with two olefinic units in E/E configurations, whereas 10S is an 18e species containing both an olefinic substituent and an alkyl B--CH unit. The reaction of 7S with methyl acetylenemonocarboxylate at ambient temperature leads to the sole 16e compound [CpCo(S2C2B10H8){CH=CH(CO2Me)}-{(MeO2C)C=CH(CO2Me)}] (11S). In contrast, 6Se does not rearrange. All new complexes 2S-4S, 5Se, 6Se, and 7S-11S were characterized by NMR spectroscopy (1H, 11B, 13C) and X-ray structural analyses were performed for 2S-4S, 5Se, 6Se, and 7S-9S.     

1,2-苯基异噁唑为氮源的铜催化苯乙烯不对称硼胺化

报道了一种以手性亚砜膦配体/铜络合物为催化剂的苯乙烯不对称硼胺化反应.该方法以联硼酸频哪醇酯(B2pin2)为硼源,以商业可得的1,2-苯基异噁唑为亲电氮源,合成了一类β-氨基硼酸酯类化合物,目标产物可以方便地转化为β-硼酯伯胺化合物,为结构多样的手性氨基化合物合成提供了一条技术途径.     

Cobalt-Promoted Transfer Hydrogenation of Azaaryl Ketones by Using Formate as the Hydrogen Source

A novel cobalt-catalyzed reduction of 2-pyridyl ketones and related heteroaryl compounds using formate as reductant was developed. Ketone substrate is activated by chelation with cobalt, which makes the present method highly selective. A possible reaction mechanism is proposed.