[Flu(Me)2CCp]2Yb(μ-Br)2Li(THF)2·THF的合成和晶体结构

为考察取代环戊二烯基或桥联环戊二烯基有机稀土化合物的性质,研究了碳桥联芴基环戊二烯基配体与卤化稀土的反应,其中,[2-(9-芴基)异丙基]环戊二烯基锂[Flu(Me)2CCpLi]与三溴化镱(YbBr3)在四氢呋喃(THF)中反应,分离得到了标题配合物[Flu(Me)2CCp]2Yb(μ-Br)2Li(THF)2·THF.X射线单晶结构测定表明配合物属单斜晶系,空间群为P2(1)/n,晶胞参数为a=1.4676(3) nm,b=1.2618(4) nm,c=2.9736(9) nm,β=98.172(18)°,Z=4,V=5.451(2) nm3,Mr=1098.84,Dc=1.339 mg·m-3,R=0.0695,wR=0.1721.中心Yb原子分别与两个环戊二烯基和两个溴原子成键,形成扭曲的四面体配位构型.Yb-Br1和Yb-Br2键长分别为0.2765(1)和 0.2738(1) nm,两个环戊二烯基平面的夹角为125.7°,中心Yb原子与两个环戊二烯基环中心的平均距离分别为0.232和0.231 nm.     

Yb(NTf2)3催化苯甲酸酯化反应

Lewis酸催化;Yb(NTf2)3催化苯甲酸酯化反应     

《精细化学品催化合成技术(下册):催化合成反应与技术》

《精细化学品催化合成技术》分上、下两册,上册(第1~6章)为"绿色催化技术",下册(第7~14章)为"催化合成反应与技术"。本册(下册)在上册叙述精细化学品合成的绿色催化技术基础上详细介绍了各种类型催化剂参与的各种类型有机     

[Li（THF）][t—BuCp）Yb（NPh2）3]的合成及晶体结构

合成了标题配合物（Ｌｉ（ＴＨＦ）４］［ｔ－ＢｕＣｐ）ＹｂＮｐｈ２）３］，经元素分析、红外光谱表征，并测定了其晶体结构。配合物正交晶系，Ｐｂｃａ空间群，晶体学参数ａ＝１．４５１５（５），ｂ＝２．２８３３（５），ｃ＝３．３５５４（６）ｎｍ；Ｖ＝１１．１２０９（５）ｎｍ＾３，Ｄｃ＝１．３１ｇ．ｃｍ＾－３；Ｆ（０００）＝４４．２３，Ｚ＝８。最后一致性因子Ｒ＝０．０４７，ＲＷ＝０．０４５，平均Ｙｂ－Ｎ键长是     

《精细化学品催化合成技术(下册):催化合成反应与技术》

《精细化学品催化合成技术》分上、下两册,上册(第1~6章)为"绿色催化技术",下册(第7~14章)为"催化合成反应与技术"。本册(下册)在上册叙述精细化学品合成的绿色催化技术基础上详细介绍了各种类型催化剂参与的各种类型有机合成反应。包括在多孔本体和负载金属催化剂上使用氢气的有机化合物催化加氢和催化加氢裂解反应;在酸碱催化剂上进行精细化学品催化合成反应;使用分子氧和过氧化物作为氧源的催化氧化反应;使用手性辅助试剂催化合成手性化     

(Me3Si)2NBCl2和(Me3Si)2NB(Cl)NHSiMe3的合成及其成环反应

自从氮化硼陶瓷纤维用聚合物先驱体法[1]合成以后,硼氮六元环化合物越来越为人们所重视[2],文中在制备氮化硼纤维先驱体的过程中,合成了其中间产物,通过热缩合成环反应,合成了含有硼氮六员环的化合物,并采用色-质联用技术对其进行了表征。1　实验部分参照文献[3],改用液氮和丙酮为冷冻剂,控制温度在-50到-40℃,搅拌下向三氯化硼的正戊烷溶液中缓慢滴加三乙胺的正戊烷溶液,滴完后Ｎ2气氛下-50℃加丙酮冷凝回流2ｈ,慢慢由-50℃升至室温,抽滤即得到白色产物Ｅｔ3ＮＢＣｌ3(Ａ)。将Ａ溶于适量苯中[4,5],加入等物质的量的三乙胺,加热回流搅拌…     

手性杯[4]丝氨酸衍生物的合成及其催化性能

以对叔丁基苯酚为原料,经环化缩合、脱叔丁基、酚羟基醚化、甲酰化和氧化反应制得5-羧基-25,26,27,28-四正丙基杯[4]芳烃(5);5与O-苄基-N-苄氧羰基丝氨酸反应制得5-(O-丝氨酸)-25,26,27,28-四正丙基杯[4]甲酸酯(7),其结构经~1H NMR,~(13)C NMR和MS(ESI)表征。研究了溶剂和水的用量对7催化性能的影响。结果表明:水为溶剂,其用量为10 eq.时,收率和非对映选择性分别为95%和3∶97 dr;当水的用量为30 eq.时,收率和非对映选择性分别为93%和98∶2 dr。     

镍配合物[N,N]NiBr2的合成及其催化乙烯齐聚研究

 吡啶甲醛类化合物与苯胺类化合物缩合形成有机配体［N，N］，\r\n它与金属镍的卤化物NiBr2作用可形成稳定的配合物［N，N］NiBr2．这\r\n种配合物在含铝助催化剂存在下显示出较高的催化乙烯齐聚的活性，所\r\n得乙烯齐聚物具有较高的支化度和较低的α－烯烃含量．实验结果表明\r\n，吡啶环与苯环上的取代基对催化反应的活性具有不同的影响，助催化\r\n剂的种类及用量、反应溶剂和乙烯压力等对该体系的催化反应活性及产\r\n物结构具有直接影响．研究结果表明，通过调节催化聚合反应的工艺条\r\n件，有可能实现控制聚合产物的分子量和分子量分布，以及提高产物中\r\nα－烯烃的含量等．     

椰壳炭磺酸催化剂制备及其对杯[4]芳烃合成反应的催化应用

以废弃椰壳为原料,经炭化和磺化制得新型固体磺酸催化剂,用于催化各种芳醛与间苯二酚的缩合反应,以较高收率(49%～95%)制得一系列杯[4]芳烃化合物,产物结构经IR、1H NMR和MS测试技术表征得以确证。     

Synthesis and crystal structure of triphenyl[tris(tetrahydrofuran)]ytterbium, Ph3Yb(THF)3

Triphenyl[tris(tetrahydrofuran)]ytterbium, Ph₃Yb(THF)₃ (1), was synthesized in high yields by the reaction of Yb with an excess of Ph₂Hg or Ph₃Bi in the presence of catalytic amounts of YbI₂(THF)₄ as well as by the reaction of Ph₂Yb(THF)₂ (2) with Ph₂Hg or Ph₃Bi. The crystal structure of complex1 was studied by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 163–166, January, 1998.     

Hydroboration of the Amino(imino)borane [Me3C(Me3Si)N]B[N(CMe3)]

The formation of four products of the type Me₃C(Me₃Si)N=BH–N(CMe₃)=BR'₂ [BR'₂ = B(CHMeiPr)₂ ( 1 ), B(c‐C₆H₁₁)₂ ( 2 ), B(C₈H₁₄) ( 3 ), B(O₂C₆H₄) ( 4 )] from the iminoborane Me₃C(Me₃Si)N–···B=···N(CMe₃) and the hydroboranes (R'₂BH)₂ is described. Crystal structure analysis reveals the molecule 1 to have an N=B–N=B backbone with two orthogonal N=B bond planes and, hence, no conjugation between the two B–N double bonds.     

Synthesis and Molecular Structure of Binuclear ansa-Bis(amidinate) Ytterbium Complex [1,3-C6H4{NC(Ph)N(SiMe3)}2]3Yb2

Russian Journal of Coordination Chemistry - The exchange reaction of anhydrous YbCl3 with [1,3-C6H4{NC(Ph)N(SiMe3)}2Li2(THF)2]2 (I) (4 : 3 molar ratio, THF) gave ansa-bis(amidinate)...     

Anionic bipyridyl complexes of lanthanides. Structure of [Yb(bipy)3][Li(THF)4]

Reactions of Sm^II, Tb^III, Tm^II, Yb^II, and Lu^III iodides with 2,2′-bipyridyllithium in THF afford [Li(THF)₄][Ln(bipy) _n ] complexes (n=3 or 4) containing trivalent lanthanides. X-ray structural analysis demonstrated that in the crystalline state, the Yb derivative has the ionic structure, [Li(THF)₄]⁺[Yb(bipy)₃]^?. In THF solutions, the reversible ligand exchange between metal atoms occurs to yield neutral compounds [Ln(bipy) _n?1(THF) _x ] and [Li(bipy)(THF) _y ]. A decrease in the temperature shifts the equilibrium to ionic pairs.     

Reaction between [MgCl2(THF)2] and [MoOCl3(THF)2]. The Crystal Structures of [Mg(THF)6][MoOCl4THF]2 and [Mg2(m̈-Cl)3(THF)6][MoOCl4THF]

Two [MoOCl₃(THF)₂] molecules are used for detachment of two Cl atoms from [MgCl₂(THF)₂]. In such reaction a green crystalline salt [Mg(THF)₆][MoOCl₄THF]₂ IV is formed. Compound IV reacts further with 3 equivalents of bis(tetrahydrofuran)magnesium dichloride, yielding a green ionic [Mg₂(m?-Cl)₃(THF)₆][MoOCl₄THF] compound V . Compound IV and V vary only in a structure of cation what indicated that the tri-m?-chlorohexakis(tetrahydrofuran)dimagnesium(II) cation in V is really formed in reaction between [Mg(THF)₆]²⁺ cation and [MgCl₂(THF)₂]. The crystal structure of compounds IV and V has been solved by X-ray diffraction method. The [Mg(THF)₆]²⁺ cation forms the tetragonally distorted octahedron with the magnesium atom in the symmetry centre. In homobimetallic di-octahedral [Mg₂(m?-Cl)₃(THF)₆]⁺ cation the magnesium atoms are surrounded by three bridging chlorine atoms and three THF molecules. The structures of [MoOCl₄THF]^? in IV and V are similar. In those anions the molybdenum atom is hexacoordinated with four chlorine atoms in equatorial plane.     

Hydrometallation of the Iminoboranes tBuB(NtBu) and [tBu(Me3Si)N]B(NtBu)

The hydrometallation of the iminoboranes XB(NtBu) ( 1 a : X = tBu; 1 b : X = tBu(Me₃Si)N) with Cp₂ZrHCl and Cp₂HfHCl gives products of the type X–BH=N(tBu)–MCp₂–Cl ( 7 a , b : M = Zr; 8 a , b : M = Hf). There is a B–H–M (3c2e) bond interaction. The BN multiple bond of the iminoboranes is more or less side‐on bound to the metal. Hence, iminoboranes again turn out to behave as analogues of alkynes.     

Simple Lanthanide Amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 as Highly Efficient Catalysts for the Nitroaldol Reaction

This contribution is to report the application of simple lanthanide amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 exhibiting a high activity toward catalyzing Henry reaction of aromatic aldehydes with nitroalkanes to give β-nitroalcohols or β-nitroolefins with a very good chemoselectivity by controlling the reaction temperatures and by selecting aromatic aldehydes. It was found that this catalytic system was compatible with a wide range of substrates of aldehydes.     

Synthesis of the mixed lithium-potassium-(bis)magnesium N-metallated/N,C-dimetallated amide [Li2K2Mg4[But(Me3Si)N]4[But[Me2(H2C)Si]N]4]: an inverse crown molecule with an atomless cavity

Unlike previous members of the inverse crown family, which are heterobimetallic and have cationic rings surrounding anionic cores, the title compound is heterotrimetallic and its "guest" anion is intramolecularly stitched into the complex fused-ring structure of its cationic "host".