N-(6-甲基-2-亚甲基吡啶)-( )-樟脑亚胺体系的不对称烷基化反应

目前,不对称合成光学活性化合物取得了较大进展,不对称合成α-氨基酸、β-氨基醇、α-取代苄胺的报道很多。但是,不对称合成生物碱类物质——α-取代氨甲基吡啶类化合物还未见文献报道,而此类化合物有潜在的应用前景。为此,我们以( )-樟脑为手性试剂     

批量离子交换层析和凝胶过滤层析在类人胶原蛋白I纯化中的应用

研究了利用批量离子交换层析与凝胶过滤层析相结合的方法纯化类人胶原蛋白I的最佳条件。分别考察了不同离子交换树脂、缓冲溶液pH、离子强度、进料蛋白浓度对批量离子交换的影响,以及不同凝胶过滤介质对凝胶过滤层析的影响。结果表明,采用阴离子交换树脂DEAE52吸附杂蛋白,缓冲液pH为7.0,NaCl浓度为0.2mol/L,进料蛋白浓度为40mg/mL,并采用凝胶过滤介质SephadexG-100进一步纯化后,类人胶原蛋白I的纯度可达到98.2%,总纯化倍数为3.1,总回收率为80.6%。SDS-PAGE分子量分析和N末端氨基酸序列分析均表明纯化后的类人胶原蛋白I与基因设计一致。     

锂离子电池负极合金CoSn和Cu-Sn的制备与表征

CoSn alloy and Cu-Sn samples were synthesized by H₂-reduction following solid-state reaction between Co(Ⅱ)， Cu(Ⅱ)， Sn(Ⅳ) and NaOH at ambient temperature. The samples were characterized by XRD， SEM. The results showed that CoSn alloy (80～200nm) is globe-shaped， ultrafine hexagonal material， and Cu-Sn alloy powder consists of two phases， i.e. Cu₆Sn₅ and Cu₃Sn. Cu-Sn powder has spherical morphology and the particle size is estimated to be 60～70nm. The electrochemical performances of CoSn alloy and Cu-Sn powder were studied using lithium-ions model cell Li/LiPF₆ (EC+DMC)/CoSn (or Cu-Sn). It was demonstrated the reversible discharge capacities for 10 cycles keep above 280mAh·g^-1 for nanophase Cu-Sn， and 60mAh·g^-1 for CoSn alloy. Differ-ential capacity plots showed that the reaction mechanisms of Cu-Sn with lithium were reversible.     

超球谐展开的收敛行为He原子的^3S态

利用相关函数－超球谐－广义Ｌａｇｕｅｒｒｅ函数方法，研究Ｈｅ原子＾３Ｓ态波函数向超球谐函数展开的收敛行为。截止于ｌ＝０，１，２的超球谐函数给出的本征能分别与组态相互作用的ｓ－，ｓｐ－，ｓｐｄ－极限能一致。仅用４４个超球谐函数，便得到了与精确的ＨｙｌｌｅｒａａｓＣＩ变分能量小数点后第５位的２＾３Ｓ，３＾３Ｓ的４＾３Ｓ态本征能吻合。     

高密度燃料HDF-1与橡胶的相容性研究

报道了在室温和70 ℃下橡胶材料G402氟硅胶、丁腈胶5171、丁腈胶4170、贮囊橡胶用合成的高密度燃料HDF-1浸泡后性能如伸长率、邵尔硬度、重量、面积体积的变化，并与采用3号喷气燃料（RP-3）实验结果进行对照。用红外光谱测定了燃料浸泡前后橡胶组成的变化。实验结果表明，G402氟硅胶和贮囊对于HDF-1和RP-3有相近的相容性，丁腈胶5171对HDF-1的相容性比对RP-3的相容性稍差，丁腈胶4170对HDF-1的相容性比对RP-3的相容性更差的结果。因此，丁腈胶5171和丁腈胶4170不能用于HDF-1储存和输送，原使用RP-3系统的橡胶密封件不能直接使用HDF-1。     

(1R,2S)或(1S,2R)-1,2-二苯基-2-氨基乙醇衍生物手性配体的合成及其用于不对称催化反应

重点报道了以（１Ｒ，２Ｓ）或（１Ｓ，２Ｒ）－１，２－二苯基－２－氨基乙醇衍生物手性配体的合成及其用于不对称催化反应的研究，如去氢氨基酸的氢化、醛的乙基锌加成、酮的还原、活泼亚甲基化合物的烷基化、醛的硅腈化和瑞福马斯基反应等．研究了手性配体的结构、底物和反应条件等对上述反应的对映选择性和催化活性的影响．     

A Facile Three-Component One-Pot Synthesis of Structurally Constrained Tetrahydrofurans, Which Are t-RNA Synthetase Inhibitor Analogues

A one-pot procedure for the efficient synthesis of a small library of t-RNA inhibitor analogues was developed. Thus,Rh2(OAc)4 catalyzed three-component 1,3-dipolar cycloaddition reactions of carbonyl ylides derived from diazoindan-1,3-dione and aldehydes with other dipolarophiles in 1,1,2,2-tetrachloroethane at 80 ℃ gave ring fused tetrahydrofurans having three stereocenters in good yield.     

Reaction of the dimethoxyaminyl radical with tertiary nitrosoalkanes as a method for the preparation of N-alkyl-N′-methoxydiazene N-oxides

The reaction of the dimethoxyaminyl radical with functionally substituted nitrosoalkanes (2) in a 2:1 ratio at 20°C gives the corresponding N-alkyl-N-methoxydiazene N-oxides (3) as a single isomer in preparative yields.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2443–2445, October, 1992.     

Nonclassical titanocene silyl hydrides

The titanocene silyl hydride complexes [Ti(Cp)2(PMe3)(H)(SiR3)] [SiR3=SiMePhCl (6), SiPh2Cl (7), SiMeCl2 (8), SiCl3 (9)] were prepared by HSiR3 addition to [Ti(Cp)2(PMe3)2] and were studied by NMR and IR spectroscopy, X-ray diffraction (for 6, 8, and 9), and DFT calculations. Spectroscopic and structural data established that these complexes exhibit nonclassical Ti-H-Si-Cl interligand hypervalent interactions. In particular, the observation of silicon-hydride coupling constants J(Si,H) in 6-9 in the range 22-40 Hz, the signs of which we found to be negative for 8 and 9, is conclusive evidence of the presence of a direct Si-H bond. The analogous reaction of [Ti(Cp)2(PMe3)2] with HSi(OEt)3 does not afford the expected classical silyl hydride complex [Ti(Cp)2(PMe3)(H)[Si(OEt)3]], and instead NMR-silent titanium (apparently TiIII) complex(es) and the silane redistribution product Si(OEt)4 are formed. The structural data and DFT calculations for the compounds [Ti(Cp)2(PMe3)(H)(SiR3)] show that the strength of interligand hypervalent interactions in the chlorosilyl complexes decreases as the number of chloro groups on silicon increases. However, in the absence of an Si-bound electron-withdrawing group trans to the Si-H moiety, a silane sigma complex is formed, characterized by a long Ti-Si bond of 2.658 A and short Si-H contact of 1.840 A in the model complex [Ti(Cp)2(PMe3)(H)(SiMe3)]. Both the silane sigma complexes and silyl hydride complexes with interligand hypervalent interactions exhibit bond paths between the silicon and hydride atoms in Atoms in Molecules (AIM) studies. To date a classical titanocene phosphane silyl hydride complex without any Si-H interaction has not been observed, and therefore titanocene silyl hydrides are, depending on the nature of the R groups on Si, either silane sigma complexes or compounds with an interligand hypervalent interaction.