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Anastasia O. Kolodiazhna Irina V. Guliaiko Oleg I. Kolodiazhnyi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2335-2346
Abstract The addition of silylphosphines to chiral aldehydes proceeds with high diastereoselectivity to give optically pure tertiary α -trimethylsiloxyalkylphosphines. The diastereomeric excesses of the addition products were achieved to 90–100%. The reaction of bis(trimethylsilyl)phenylphosphine with the acetonide of (R)-glyceraldehyde provides diastereomerically enriched tertiary bis(glyceryl)phosphines. 相似文献
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不对称催化是有机化学研究的前沿领域和发展方向.近10年来,手性配体的研究得到了长足的发展,大量的小分子手性配体被报道,其中许多手性配体展示了优异的催化性能.但是由于昂贵的手性配体(金属催化剂)分离、回收和再利用的问题,从而限制了小分子催化剂的应用.因此,解决手性金属催化剂的分离与回收问题是不对称催化研究领域的一个热点问题.为了解决这一关键问题,国内外科学家从负载的角度出发已经成功地发展了众多的研究方法,无机负载法、交联高分子负载法、可溶性高分子负载法、树状大分子负载法等.许多负载的手性金属催化剂已经表现出优异的催化活性和高的对映选择活性. 相似文献
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Abstract— Photochemical and γ-ray-induced reactions of purines with amines are described. These lead to the appropriate 8-substituted purines. The photoproducts were obtained in yields of up to 100% by the use of a variety of photosensitizers, including peroxides. A free radical mechanism is proposed for these reactions.
Such reactions may be relevant to the problem of the nature of DNA-protein cross-links induced by ultraviolet radiation. 相似文献
Such reactions may be relevant to the problem of the nature of DNA-protein cross-links induced by ultraviolet radiation. 相似文献
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本文阐明了(RO)_2S=P(S)_nS=P(OR)_2 (R=CH_3,C_2H_5;n=2,3,4)与R_2~'NH(R'=C_2H~6,iC_6H~7)的反应。从几个方面证明其反应产物之一,就是相应二硫代磷酸酯的胺盐:(RO)_2S=PS~-·H_2+NR_2~'。反应过程中所有S-S键断裂,从而证明上述有机磷多硫物不是R_n~'NH的烷基化试剂。反应提供了合成(C_3H_5O)_2S=P SN(C_2H_5)_2,(C_2H_5O)_2S=PS~-·H_2+N(C_2H_5)_2和(C_2H_5)_2NSN(C_2H_5)_2的新路线。 相似文献
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1INTRODUCTIONThesynthesisofopticallypurechiralcompoundshasgainedgreatimportance,particularlyintheareasofphannaceuticals,agrochemical,flavorsandfragrances[l].SeveraldifferentstrategiesareappliedtomanufactUreopticallypurechiralsubstrates.Amongthem,asymmetriccatalysisprovidespowerfulanduniqueadvantages,perhapstheforemostisthe"multiplicationofchirality",alargequantityofchiralproductcanbeproducedusingacatalyticamountofachiralsourceIZI.However,uptonowonlyafewprocesseshavemadethestepfromanacade… 相似文献
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Janarthanan Gopalakrishnan M. N. Sudheendra Rao 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):754-764
Though aminophosphines have been known for a century, and a large variety of such compounds has been synthesized for different aspects of their chemistry, until now, no examples are available on phosphines containing three different amino substituents. In this study, the first examples of such chiral tris(amino)phosphines and o-phenylenedioxo(amino)phosphines were successfully synthesized using condensation reactions, and they were converted to their respective selenides using a simple oxidative addition reaction. The compounds are characterized by IR, 1H, and 13C NMR spectral techniques, and the spectral aspects are presented. The spectral studies (i) indicated that they are indeed powerful tools for structural elucidation of compounds; (ii) showed the effect of heavier selenium atom on the P–N bond rotation process; and (iii) further supported the fact that dipolar structure predominates over the π-bond structure for the aminophosphine selenides. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
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本文报道 NaBH_4-CoCl_2可使氧化苯乙烯类化合物发生区域选择性开环,主要生成β-苯乙醇衍生物。对于氧化二苯乙烯类化合物,由于受到苯环的空间阻碍,使其开环能力减弱,如反式氧化二苯乙烯比顺式异构体更难于开环。 相似文献
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由D-甘露醇出发合成了两种新型的手性1,6-双膦:1,6-双(二苯膦基)-2,3,4,5-二亚(艹卡)基-D-甘露醇和1,6-双(二苯膦基)-3,4-亚(艹卡)基-2,5-亚甲基-D-甘露醇。 以这两种手性配位体的Rh(Ⅰ)配合物为催化剂用于α-乙酰氨基肉桂酸的不对称氢化反应,但都未观察到对映选择性,而且由第一种配位体参加的反应,也未显示氢化活性,对此本文也作了初步的说明。 相似文献
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在乙醇中合成出三个希土硝酸盐与冠醚(+)-12,17-二乙基-1,4,7,10-四氧杂-13,16-二氮杂环十八烷(L)的配合物。经元素分析确定其组成为[Ln(NO3)2·L(+)]NO3(Ln=La, Pr, Nd)。通过UV-VIS和FI-IR、电导测定等方法研究了配合物的配位结构和性质。测定并讨论了手性配合物[Pr(NO3)2·L(+)]NO3的CD谱。 相似文献
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设计和制备了一种用于手性化合物的高效液相色谱拆分的新型手性固定相(CSP)。该固定相以构象刚性的L-脯氨酸为手性选择子,经引入保护基、萘酰胺化、加氢脱保护基、酰胺化和与LiChrosorbNH25μm微粒硅胶偶联等5步反应而制得。在此CSP结构中引入萘酰胺,可增强CSP和手性溶质之间的π-π相互作用,以提高该CSP的对映体选择性。报道了4种N-3,5-二硝基苯甲酰-DL-氨基酸甲酯对映体色谱拆分的初步结果,对映体选择性在1.04~1.18之间。色谱拆分条件的优化和该固定相的应用将有待于进一步研究。 相似文献
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Four series of new phosphorus compounds with general formulas Ⅰ, Ⅱ, Ⅲ and Ⅳ have been prepared by the reactions of phosphoro-(or phosphono-)bis-(isothiocyanatido)-thioates separately with amines. The structures of these compounds have been confirmed by IR and ~1HNMR. In addition, some of them have been further identified by MS and X-ray. 相似文献
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《Journal of Coordination Chemistry》2012,65(1-4):227-236
Abstract Stereoselective electron-transfer between optically active Λ-[Co(EDDS)]? and [Co(diamine)3]2+ (diamine = racemic-1,2-diaminopropane (pn); R-1,2-diaminopropane (R-pn)) have been investigated in aqueous and in DMSO solutions. In aqueous solution, the reaction between Λ-[Co(EEDS)]? and [Co(pn)3]2+ produces four conformational isomers of the [Co(pn)3]3+ complex which have the Λ-forms in excess. Their optical purities are increased ob3>lelob2> lel2ob> lel3 . In contrast, the reaction in DMSO results in more δ isomers than Λ and the sequence of optical purities are in reversed order. The reaction between Λ-[Co(EDDS)]? and [Co(R-pn)3]2+ in aqueous solution produces two conformational isomers of [Co(R-pn)3]3+; their absolute configurations are identified as δ-lel2ob and Λ-ob3 . In DMSO, in contrast, the reaction produces only one isomer which is identified as δ-lel2ob. 相似文献