Synthesis and Crystal Structure of Dinuclear Zinc（II） Complex with 3—Me—N—oxopyridine—2—thiol

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｔｕｄｉｅｓｏｆｔｈｅｃｏｏｒｄｉｎａｔｉｏｎｃｈｅｍｉｓｔｒｙｏｆｚｉｎｃ(ＩＩ)ｈａｖｅａｒｏｕｓｅｄｍｏｒｅａｎｄｍｏｒｅｉｎｔｅｒｅｓｔｉｎｌａｓｔｄｅｃａｄｅｉｎｖｉｅｗｏｆｔｈｅｉｒｂｉｏｌｏｇｉｃａｌｍｏｄｅｌｉｎｇａｐｐｌｉｃａ ｔｉｏｎｓ[1 ,2 ] ａｎｄｓｏｌｉｄ ｓｔａｔｅｍａｔｅｒｉａｌｓ[3 ,4] .ＷｅｈａｖｅｂｅｅｎｉｎｔｅｒｅｓｔｅｄｉｎｔｈｅｓｔｕｄｙｏｆｔｒａｎｓｉｔｉｏｎｍｅｔａｌｃｏｍｐｌｅｘｅｓｏｆＮ ｏｘｏｐｙｒｉｄｉｎｅ 2 ｔｈｉｏｌ(…     

Some features of an SmI2−(Me2N)3P—THF system. Transformation of esters into dimethylamides

Sm^il-intermediates generated upon addition of (Me₂N)₃P to a solution of SmI₂ in THF exhibit the properties of a single-electron reducing agent and an N-nucleophile. In particular,N,N-dimethylamides are formed from esters. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 327–329, February, 2000.     

Über die kristallstrukturen von Me3SnO2PCl2 und Me3SnO2PMe2 und das schwingungsspektrum von Me3SnO2PMe2

Me₃SnO₂PMe₂ is prepared by treatment of Me₃SnNEt₂ with Me₂PO₂H in methylene chloride. The vibrational spectrum is discussed. Crystal structure determinations from X-ray diffraction data have been carried out with single crystals of Me₃SnO₂PMe₂ (R 0.076, 819 observe independent reflexions), and Me₃SnO₂PCl₂ (R 0.051, 1127 observed independent reflexions), showing polymer chains of SnMe₃ groups and O₂PX₂ (X = Cl, Me) units in both cases. The phosphinate chains form vast helices whereas the dichlorophosphate forms almost planar chains.     

Synthesis,structure and stereochemistry of diiodide complexes (E)[(η5-t-BuC5H3)Fe(CO)2I]2 (E = Me2Si,Me2SiSiMe2, and Me2SiOSiMe2)

Reactions of diiron complexes (E)[⁵-t-BuC₅H₃)Fe(CO)]₂(-CO)₂ [E = Me₂Si (1), Me₂SiSiMe₂ (2), and Me₂SiOSiMe₂ (3)] with iodine in CHCl₃ yielded diiodide complexes (E)[⁵-t-BuC₅H³)Fe(CO)₂I]₂ [E=Me₂Si (5), Me₂SiSiMe₂ (6), and Me₂SiOSiMe₂ (7)]. Like (1–3), complexes (5–7) also exists as mixtures of cis and trans isomers even though the Fe–Fe bond in (1–3) has been cleaved. When the pure isomers (1–3) reacted with iodine respectively in CHCl₃, the cis isomers (1c–3c) yielded only the cis products (5c–7c), whereas the trans isomers (1t–3t) yielded only the trans isomers (5t–7t). This indicates that iodination of bridged diiron complexes is stereospecific. Similar treatment of trans-(Me₂Si)[{⁵-t-(heptyl)C₅H₃}Fe(CO)]₂(-CO)₂ (4t) with iodine gave only the trans product (Me_2Si)[{⁵-t-(heptyl)C₅H₃}Fe(CO)₂I]₂ (8t). The molecular structure of (5t) was determined by X-ray diffraction.     

Investigation of Isomerization of 2—Seleno—1,3,2—diazaphospholidine Derivatives

For the first time the isomerization of 1,3,2-diazaphospholidine-2-sclenide dervatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR, ^1H NMR,^31P NMR, elemental analysis and X-ray crystallography. The mechanism of isomerization was also proposed.     

Synthesis and structures of bridged diruthenium complexes (E)[η5-C5H4)Ru(CO)]2(μ-CO)2 (E = Me2Ge,Me2SiOSiMe2, Me2SiOSiMe2OSiMe2)

A series of bridged diruthenium complexes (E)[(⁵-C₅H₄)Ru(CO)]₂(-CO)₂ (E = Me₂Ge (2); Me₂SiOSiMe₂ (3); Me₂SiOSiMe₂OSiMe₂ (4)) has been prepared by reacting Ru₃(CO)₁₂ with Cp₂E in refluxing heptane. The molecular structures of (2) and (4) have been determined by X-ray diffraction.     

（η^5—4,7—Me2—Ind）2Zr（CH2Ph）2／烷基铝催化乙烯齐聚的研究

考察了(η5-4,7-Me2-Ind)2Zr(CH2Ph)2与EtnAlCl3-n(n=2(A),n=1(B),n=1.5(C))所组成的二元催化体系,在不同的反应温度、陈化温度、铝锆比下催化乙烯齐聚的活性和选择性.结果表明,在相同的反应条件下,3种催化体系的催化活性顺序为B>C>A;选择性则相反,为B<C<A.在最佳反应条件下,(η5-4,7-Me2-Ind)2Zr(CH2Ph)2/EtAlCl2二元催化体系对乙烯聚合的催化活性为1912.3g齐聚物/(gZr*h),对C4～10烯烃的选择性为96.6%.     

Synthesis and Crystal Structure of [（ArO）2Sm（OPPh3）（μ—OH）]2（ArO=2,6—tBu—4—Me—C6H2O）

1 INTRODUCTION In recent years, the syntheses, structures and reactivities of aryloxo lanthanide complexes have attracted a great deal of attention due to their various applications as homogeneous catalysts for organic reactions and precursors for organolan- thanide syntheses[1]. However, the reactivity of divalent lanthanide aryloxides has seldom been studied[2]. We have previously reported that (ArO)2- Sm(THF)4 (ArO = OC6H2-2,6-di-tert-butyl-4-Me) can efficiently initiate the poly…     

用毛相色谱分析研究由Me2SiCl2与Li合成(Me2Si)6的反应

用气相色谱分析由Me2SiCl2(1)与Li在各阶段反应的生成物, 发现除偶联反应外, 还有环化、环转化平衡、聚合和裂解等反应, 它们随反应条件的改变而变化。当反应液中含有催化量的Me3SiSiPh3(2)时, 可以促进热力学稳定的(Me2Si)6的生成, 进一步证明了亲核试剂对合成(MeSi)6的催化作用。在一定的反应条件下, 产物的收率达80%以上。     

Synthesis and structure of the first representative of pentacoordinate C,O-chelates with a dipeptide fragment,the fluorosilane Ts—Gly—(S)-Pro—N(Me)CH2SiMe2F

A reaction of bicyclic 2-sila-5-piperazinone, 2,2,4-trimethyl-1,4-diaza-2-silabicyclo-[4.3.0]nonan-5-one containing a proline moiety, and N-tosylglycine acyl chloride with subsequent hydrolysis of the primary unstable product to the intermediate disiloxane and its treatment with BF₃?OEt₂ furnished a first representative of pentacoordinate C,O-chelate halosilanes with a dipeptide fragment, namely, Ts—Gly—(S)-Pro—N(Me)CH₂SiMe₂F.

     

N2S2 macrocyclic ligands. Synthesis and characterization of novel transition metal complexes of the type [LM(Si2Me6NH)2]2+ and [L′M(Si2Me6NH)2]2+

Summary Novel N₂S₂ macrocyclic ligands, L and L [SS-diethyl(1,3-diaminopropane) dithiocarbamate], [SS-cyclohexyl spiro-(1,3-diaminopropane) dithiocarbamate] and their complexes with Mn^II, Fe^II, Co^II, Ni^II and Cu^II have been characterized by elemental analyses, conductivity measurements, i.r., u.v.-vis. and n.m.r. spectra. The divalent transition metal complexes appear to be square planar and achieve octahedral geometry when treated with bis(trimethylsilyl)-amine to yield new heterobimetallic complexes.     

Chemo-enzymatic Synthesis of Z-Asp-Val-Tyr-NH_2——A Precursor Tripeptide of Thymopentin

Z-Asp-Val-Tyr-NH2,a precursor tripeptide of thymopentin(TP-5),was successfully synthesized by a combination of chemical and enzyme methods.Firstly,the precursor dipeptide Val-Tyr-NH2 was synthesized by a novel chemical method in four steps including the preparation of NCA-Val,the esterification of L-tyrosine and the ammonolysis of L-tyrosine ethyl ester,and the formation of Val-Tyr-NH2 from NCA-Val and L-Tyr-NH2.Secondly,a thermolysin,thermoase PC 10F was used to catalyze the formation of Z-Asp-Val-Tyr-NH2 in an aqueous/organic solvent diphase system with Z-Asp-OH and Val-Ty-NH2 as the substrates under thermodynamic control.The optimum conditions were pH=6.5,40 ℃,thermoase 100 mg,in 2-(N-morpholino) ethanesulfonic acid MES/NaOH(containing 5 mmol/L CaCl2) of n-butanol system(15/85,volume ratio) for 20 h in a maximum yield of 27.02%.     

Synthesis of 3,7—Disubstituted 1,4—Benzodiazepin—2—one

A series of 3-methoxycarbonylpropoxy-7-(imidazol-4-ylpropinamide)-1,3-dihydrogen-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-ones,as farnesyltransferase(Ftase) inhibitors,were synthesized. The preparation of the key intermediate,7-amino-3-methoxycabonylpropoxy-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one,was improved.     

Reactivity of the tethered alkyl uranium bonds of (η5:κ1-C5Me4SiMe2CH2)2U

Uranium-carbon bond reactivity has been investigated with the bis(tethered silylalkyl) uranium metallocene (η⁵:κ¹-C₅Me₄SiMe₂CH₂)₂U, 1. Tert-butyl nitrile, ^tBuCN, inserts into both of the tethered U-C bonds to produce the bis(tethered ketimide) complex [η⁵:κ¹-C₅Me₄SiMe₂CH₂C(^tBu)N]₂U, 2, which has unusually bent U-N-C bond angles. Carbon dioxide also inserts into both U-C bonds of 1 yielding the bis(tethered carboxylate) (C₅Me₄SiMe₂CH₂CO₂)₂U, 3. Neither PhCCPh nor PhCCH insert into the U-C bonds, but PhCCH cleaves the silylalkyl tethers in 1 to generate (C₅Me₄SiMe₃)^1? ligands in the complex (C₅Me₄SiMe₃)₂U(CCPh)₂, 4.