Darstellung,Kristallstruktur und spektroskopische Charakterisierung von P4O6Se3

Synthesis, Crystal Structure, and Spectroscopic Characterization of P₄O₆Se₃ P₄O₆Se₃ has been prepared for the first time as a pure substance by photochemical selenation of P₄O₆ with red selenium. The compound crystallizes in a monoclinic system with space group P2₁/a (a = 973.6(2); b = 846.9(2); c = 1277.7(3) pm; β = 90.56(2)°; Z = 4; 1358 diffractometer data; R₁ = 0.044; wR² = 0.099). Bond lengths and angles within the molecule as well as the arrangement of the molecules within the crystal are discussed; vibrational (IR and Raman) and ³¹P-n.m.r. (solution) data are given.     

三价铟化合物在有机合成中的应用

综述了近年来三价铟化合物促进的多种有机反应及其在有机合成中的应用,其中重点讨论了三价铟化合物促进下的碳-碳键和碳-杂原子键的形成反应.     

A total synthesis of spiruchostatin A

We achieved the total synthesis of the histone deacetylase inhibitor spiruchostatin A, as the prelude to the preparation of a combinatorial library of its analogues. Two key reactions were an asymmetric acetate aldol reaction using a Zr-enolate and macrolactonization using the Shiina method.     

ITSTUDIES ON THE EFFECT OF UREA ON THE COMPATIBILITY OF PMMA/PVC MIXTURES IN DMF BY A DILUTE- SOLUTION VISCOMETRY METHOD

The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show thatthe polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree ofcompatibility of the polymer mixtures has been studied in terms of the compatibility parameters (△b_m and △[η]_m). It wasfound that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimumat 0.5 M urea.     

Reactions of neodymium(ii), dysprosium(ii), and thulium(ii) diiodides with cyclopentadiene. Molecular structures of complexes CpTmI2(THF)3 and [NdI2(THF)5]+[NdI4(THF)2]–

The reactions of LnI₂ (Ln = Nd (1) or Dy (2)) with cyclopentadiene (CpH) in THF at 0 °C afforded the CpLnI₂(THF)₃ complexes in 65—67% yields. The reaction of thulium diiodide (3) with an excess of CpH at 60 °C produced CpTmI₂(THF)₃, Cp₂TmI(THF)₂, and TmI₃(THF)₃ in 21, 58, and 63% yields, respectively. The reactions of 1 and 2 with pentamethylcyclopentadiene (Cp*H) in THF were accompanied by disproportionation giving rise to the Cp*₂LnI(THF)₂ and LnI₃(THF) _x complexes. Neodymium triiodide was isolated in the ionic form [NdI₂(THF)₅]⁺[NdI₄(THF)₂]^–. Its structure and the structure of CpTmI₂(THF)₃ were established by X-ray diffraction analysis.     

取代肉桂酰甘氨酸酯的合成

在N-甲基吡咯烷酮(NMP)促进下,取代肉桂酸(1a^1g)与二氯亚砜(SOCl2)在20℃酰氯化反应0.5 h,再加入甘氨酸乙酯盐酸盐,在40℃下酰胺化反应4 h,n(取代肉桂酸)/n(SOCl2)/n(甘氨酸乙酯盐酸盐)=1.0/1.2/1.4,合成了一系列取代肉桂酰甘氨酸乙酯(2a^2g),其结构经1H NMR、13C NMR、IR和MS(EI)确证。并探讨了NMP促进取代肉桂酰甘氨酸乙酯反应可能的机理。     

Overwhelming electrochemical oxygen reduction reaction of zinc-nitrogen-carbon from biomass resource chitosan via a facile carbon bath method

Developing high efficiency and low cost electrocatalysts is critical for the enhancement of oxygen reduction reaction (ORR), which is the fundamental for the development and commercialization of renewable energy conversion technology. Herein, zinc-nitrogen-carbon (Zn-N-C) was prepared by using biomass resource chitosan via a facile carbon bath method. The obtained Zn-N-C delivered a high specific surface area (794.7 cm²/g) together with pore volume (0.49 cm³/g). During the electrochemical evaluation of oxygen reduction reaction (ORR), Zn-N-C displayed high activity for ORR with an onset potential E₀ = 0.96 V_RHE and a half wave potential E_1/2 = 0.86 V_RHE, which were more positive than those of the commercial 20 wt% Pt/C benchmark catalyst (E₀ = 0.96 V_RHE and E_1/2 = 0.81 V_RHE). In addition, the Zn-N-C catalyst also had a better stability and methanol tolerance than those of the Pt/C catalyst.     

Solid state synthesis and structure of two novel polyoxometalates [(n-Bu)4N]4[M6O19][Ag2I4](M?Mo,W)†

The reaction of [NH₄]₂[MO₂S₂], AgI and (n-Bu)₄NBr in solid state produced the polyoxometalates [(n-Bu)₄N]₄[M₆O₁₉][Ag₂I₄] (1, M? Mo; 2, M? W) which were structurally determined. The crystals of 1 and 2 are isomorphous, monoclinic, space group P2₁/c. 1, a = l.6624(2), b=1.6699(3), c=l.7217(2) nm, β=98.29(1)°, V=4.729(1) nm³, Z=2, R=0.040, R_w“0.037; 2, a = 1.6636(3), b = 1.6733(3), c = 1.7190(3) nm, β=98.25(1)°, V=4.736(l) nm³, Z = 2, R = 0.038, R_w = 0.047. The results of the structure determination showed that the two compounds had the same structures whose skeletons are composed of [Ag₂I₄]². and [M₆O₁₉]^2-. The difference of them and heteropolymetalate compounds synthesized in solution is that the title compounds contain cluster. ion, heteropolymetalate and organic cations, while the latter is only composed of heteropolymetalate and organic cations.     

EFFECT OF MOLYBDENUM PROMOTER ON THE Cu-Co BASED CATALYSTS

The synthesis of mixed alcohols (C1-C5) from syngas has been studied at 6. 0 MPa over modified Co/CuLaZr catalysts. The molybdenum addition enhanced greatly the activity and the selectivity to alcohols. The improvement of hydrogenation capacity of the system via a reversible spillover effect of hydrogen could explain this effect, together with a great capacity of CO insertion, illustrated by the effect of C2H4 addition as a probe to syngas. Under our experimental conditions, a mixed alcohol production of 147.1g/kg. cat/h containing a proportion of 33. 1% of higher alcohols (C2 OH) was obtained with a selectivity to ROH of 52. 8%.     

Convenient preparative method for synthesis of methyl (Z)-3-aryl-2-(carbobenzoxyamino)acrylates by Wittig—Horner reaction with the use of Et3N as a base

The Wittig—Horner reaction of CbzNHCH(CO₂Me)P(O)(OMe)₂ (1) with ArCHO (2) in the presence of Et₃N as a base affords methyl (Z)-3-aryl-2-(carbobenzoxyamino)acrylates (3) with high degrees of diastereoselectivity (Z)/(E) > 101. One recrystallization of the crude product is sufficient to obtain isomerically and chemically pure (Z)-3.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2218-2220, November, 1995.The authors are grateful to the Dupont company (USA) for financing this study