β-砜基醇衍生物还原中的基团效应

比较芳香族砜基和脂肪族砜基对钠-汞齐还原β-砜基醇衍生物反应的影响。在还原β-苯基砜基醇衍生物的反应条件下,β-叔丁基砜基醇衍生物并不能得到还原去砜基的烯烃。β-苯基砜基醇衍生物可能是经过单电子转移消除的机理,而β-叔丁基砜基醇甲磺酰化物则经α-砜基碳负离子的消除过程得到烯烃基砜。     

不饱和取代环戊二烯基钛衍生物的合成和反应

利用不同方法合成了烯丙基、环戊烯-[2]-基、甲基(或乙基)环戊烯-[2]-基、环已烯-[2]-基和环已基等不饱和取代茂基茂基二卤化钛。烯丙基茂基钛衍生物中的环上烯丙基呈现正常的亲电加成反应,它们与HBr,Br_2,ICl和IBr反应生成对应的卤代衍生物。     

7,8-亚甲二氧基-4-氧代-3,4-二氢嘧啶并[4,5-b]喹啉衍生物的合成

为了寻找具有药理活性的喹啉衍生物, 我们合成了五个新的喹啉衍生物和十一个7,8--亚甲二氧基-4-氧代-3,4-二氢嘧啶并[4,5-b]喹啉衍生物. 这些化合物的结构均经核磁共振光谱, 红外光谱和元素分析予以证实 .     

3-杂环基硫取代-1,3,4,5-四氢-2-氧代-苯并氮杂衍生物的合成

以芳酰肼为原料, 合成了一系列3-巯基-5-芳基-1,2,4-三唑、2-巯基-5-芳基-1,3,4-噁二唑和2-巯基-5-芳 基-1,3,4-噻二唑, 并通过硫原子对3-溴-2-氧代-苯并氮杂3-位上的亲核取代反应将杂环化合物引入了苯并氮杂的结构当中, 合成了32个新的苯并氮杂杂环衍生物. 为提高其在有机溶剂中的溶解性, 在苯并氮杂的N原子上引入乙酸乙酯和乙酸叔丁酯基取代基, 合成了36个新衍生物. 所有化合物经质谱、核磁共振谱及元素分析确证了结构并初步测定了抗菌活性.     

双（甲基二茂铁基）代烷羟的合成

二茂铁衍生物在复合固体火箭推进剂中用作燃速催化剂,但其挥发性和迁移性较大,直接影响储存或使用时导弹的弹导性能。本文报导三种新型燃速催化剂:双(甲基二茂铁基)甲烷,2,2-双(甲基二茂铁基)丙烷和2,2-双(甲基二茂铁基)丁烷的合成和表征。小型试验表明其催化活性、挥发性及迁移性能均优于国内目前使用的叔丁基二茂铁。     

双-β-萘基丙烷及其衍生物的低温荧光光谱

前文报道了合成一系列1,3-双-β-萘基丙烷的衍生物C_(10)H_7CHXCH_2CH_2C_(10)H_7,在次甲基链的第一位碳原子上分别引入OH、OAc及Cl等基团,并测定了它们的荧光光谱。从荧光光谱的结果可以看出,它们都能形成分子内激基缔合物(excimer)。最近,我们又合成了CN取代的衍生物,测定了这一系列双-β-萘基丙烷衍生物的低温荧光光谱,并计算出它们形成分子内激基缔合物所需之活化能。由于在溶液中激基缔合物的形成是扩散控制过程,在低温条件下升高温度将有利于激基缔合物的形成。     

3-杂环基硫取代-1,3,4,5-四氢-2-氧代-苯并氮杂衍生物的合成

以芳酰肼为原料,合成了一系列3-巯基-5-芳基-1,2,4-三唑、2-巯基-5-芳基-1,3,4-噁二唑和2-巯基-5-芳基-1,3,4-噻二唑,并通过硫原子对3-溴-2-氧代-苯并氮杂3-位上的亲核取代反应将杂环化合物引入了苯并氮杂的结构当中,合成了32个新的苯并氮杂杂环衍生物.为提高其在有机溶剂中的溶解性,在苯并氮杂的N原子上引入乙酸乙酯和乙酸叔丁酯基取代基,合成了36个新衍生物.所有化合物经质谱、核磁共振谱及元素分析确证了结构并初步测定了抗菌活性.     

2,5-二噻吩基吡咯衍生物的合成与应用研究进展

2,5-二噻吩基吡咯衍生物具有良好的环境稳定性和电化学性质,在光电子领域有广泛的应用前景.综述了2,5-二噻吩基吡咯衍生物中噻吩环和吡咯环上不同位置取代衍生物的合成方法,并对2,5-二噻吩基吡咯衍生物在电致变色器件、光电子器件、传感器等方面的应用进行了概述.     

钯催化的三元级联反应合成3-烯基-2-氨基喹啉及其衍生物

研究了一种三元级联反应合成3-烯基-2-氨基喹啉及其衍生物的方法。以二溴代苯胺、叔丁基异氰酸酯和丙烯酸酯为起始原料,在钯催化下,130℃下反应8～12h,合成3-烯基-2-氨基喹啉及其衍生物,均获得较好的收率。并对合成的目标化合物通过NMR谱学进行结构表征。     

二茂基镧系硝基甲烷阴离子衍生物的合成及其热稳定性

自从1954年首次合成了三茂基镧系化合物以来,人们已大量合成和研究了茂基镧系衍生物。如何合成新型稳定的茂基镧系衍生物,以便进一步研究它们的各种性质,一直是金属有机化学家十分感兴趣的课题。而迄今为止,仍未见茂基镧系硝基衍生物的文献报道。我们按文献方法通过三茂基镧系化合物与硝基甲烷反应,成功地合成了五个新的茂基镧系硝基甲烷阴离子衍生物。即:Cp_2Nd(CH_2-NO_2)(1),Cp_2Sm(CH_2NO_2)(2),Cp_2Gd(CH_2-     

Nin-cyclohexyloxycarbonyl group as a new protecting group for tryptophan

Several new protecting groups were introduced at the Nⁱⁿ-position of tryptophan, and their reactivities were examined under the conditions used for peptide synthesis by Boc-strategy. Among them, the cyclohexyloxycarbonyl (Hoc) group was found to be the most suitable in terms of stability during elongation of the peptide chain and removability at the final HF reaction without resorting to the use of thiols.     

The methyl group as phosphate protecting group in nucleotide syntheses

A novel method is described for the removal of a methyl protecting group from phosphotriesters in oligonucleotides.     

The t-butyl group as sensor group of the ortho effect

The ¹³C chemical shift difference between the Me group C atoms and the quaternary C atom of the t-Bu group in 58 p-, m- and o-substituted t-butyl-benzenes has been measured and analysed in terms of inductive. mesomeric and proximity effects. It is shown that the ortho effect is too complex to justify a unified explanation by a correlation treatment.     

Molecular torus group

Generally speaking, the highest symmetry of M?bius cyclacene molecule possesses the C₂ symmetry based on the theory of point group according to the previous works. However, based on the topology principle, the fundamental group of M?buis strip is an infinite continuous cyclic group and its border is made up of twice of the generator. Of course, the M?bius strip-like molecule is associated with a finite discrete cyclic symmetry group. For the cyclacene isomers constructed by several (n) benzene rings, these isomers include: the common cylinder Hückel cyclacene (HC-[n]) molecules, the M?bius cyclacene (MC-[n]) molecules by twisting the linear precursor one time (180°), and the multi-twisted M?bius strip-like cyclacene (M ^m C?[n]) molecules by twisting the linear precursor m times (m × 180°). The relevant results suggest that in addition to the point symmetry, there is a new kind of symmetry called the torus screw rotation (denoted as TSR). In this article, we take the M ^m C?[n] molecules as examples to discuss their TSR group and point group symmetry, and the relative symmetry adaptive atom sets as well as their atomic orbital (AO) sets. Here, the Cartesian coordinates is not quite fit for the investigation of these AOs, so it is replaced by either the torus orthogonal curvilinear coordinates (for M ^m C?[n] molecule) or the cylinder orthogonal curvilinear coordinates (for HC-[n] molecule). According to the features of cyclic group, the character table of the irreducible representation of the TSR group could be constructed easily. Some other relevant point-group symmetries maybe also belong to the molecule, so its symmetry maybe called as the torus group symmetry. For multi-twisted M?bius strip-like molecule, there are some correlations in topology characteristics.     

p-Anisyl group: A versatile protecting group for primary alcohols

A primary alcohol can be protected as a highly stable p-anisyl ether, which undergoes mild oxidative deprotection by ceric ammonium nitrate.