全氟烷基磺酰亚胺盐催化芳香化合物硝化反应的研究

利用系列全氟烷基磺酰亚胺盐[M(NPf₂)_n]作为一种新型的Lewis酸催化剂，用于催化芳香化合物与等摩尔65% (m∶m)硝酸的硝化反应. 通过考察不同的催化剂、反应时间、反应温度和反应介质效应等因素对甲苯硝化的影响，以及比较1 mol% Yb[N(C₄F₉SO₂)₂]₃催化不同结构的取代芳烃硝化反应的效果，表明全氟烷基磺酰亚胺盐不仅具有环境友好和原子经济的特点，而且是一类比常规Lewis酸更有效的、芳香化合物硝化反应的催化剂.     

MCM-41负载双（全氟烷基磺酰亚胺）催化对苯二酚和叔丁醇的烷基化反应

合成了MCM-41负载的双（全氟烷基磺酰亚胺）催化剂 (HN(SO₂R_f)₂,R_f为全氟烷基)，并用XRD, FTIR, SEM, TG-DTA and N₂-吸附技术等对它们的结构进行了表征。将这些负载催化剂（HN(SO₂R_f)₂/MCM–41）用作对苯二酚和叔丁醇的烷基化反应的催化剂，研究了各种反应条件对该反应的影响。在优化反应条件下，仅用5 mol% HN(SO₂C₄F₉)₂/MCM-41催化该反应，可以得到高产率（52.0%）的2－叔丁基对苯二酚。研究结果表明，该新型负载催化剂可以至少重复使用6次，而其催化活性基本不变。     

八烷氧基2，3-萘酞菁锌(Ⅱ)的合成及荧光光谱研究

采用在强有机碱1，8-二氮杂双环［5,4,0］+--7烯(简称DBU)存在下的醇溶剂中，由“分子碎片”与锌盐通过模板反应的新方法合成了一组八烷氧基2，3-萘酞菁锌配合物(Zn(RO)_{8NPc, 其中R=C4H9、 C8H17、C12H25, NPc=C48H16N8)。产物进行了元素分析和红外光谱分析}     

含硅路易斯酸的发展及其在有机合成中的应用

综述了含硅路易斯酸R₃SiX [X＝I, OTf, NTf₂, C(C₆F₅)Tf₂等]和(R₃SiX＋ML_n)的发展、合成以及它们在有机合成中的应用. 它们主要被用来催化Aldol, 烯丙基化, Diels-Alder, Ene和Friedel-Crafts等反应. 催化剂的用量一般为0.5～20 mol%, 并随着催化剂的活性不同, 反应产率从一般到良好不等. 催化剂活性顺序为R₃SiNTf₂＞R₃SiOTf, (R₃SiX＋ML_n)＞R₃SiX. 也对近年出现的手性含硅路易斯酸的发展和应用进行了概述, 当手性双-(多氟甲磺酰)-亚胺基硅烷用于催化环戊二烯和丙烯酸甲酯的Diels-Alder反应时, ee值高达54%.     

反离子对氟表面活性剂的影响1. 表面活性及胶团化作用

通过表面张力和荧光探针法研究了全氟辛酸钠、全氟辛酸铵以及全氟辛酸四烷基铵[C₇F₁₅COON(C_nH_2n+1)₄, n＝1, 2, 3, 4]的表面活性以及胶团化作用, 系统地讨论了各种反离子, 特别是反离子大小的影响. 结果表明, 与普通碳氢表面活性剂不同, 反离子对这类氟表面活性剂的表面活性以及胶团化作用有很大影响. 表面活性剂的临界胶束浓度(cmc)随反离子的增大而下降; 饱和吸附层中平均每个分子所占的面积则大致随反离子的增大而增大. 而表面张力的变化则较为复杂. cmc时的表面张力随反离子的增大先上升(从全氟辛酸铵到全氟辛酸四乙铵)后下降(从全氟辛酸四乙铵到全氟辛酸四丁铵). 通过反离子的空间位阻、疏水性、插入以及电荷屏蔽效应对上述结果做了解释.     

非对称笼间电子迁移异构体与电场诱导电子迁移

基于密度泛函理论研究了非对称双笼型单分子溶剂化电子e^-@C₂₄F₂₂(NH)₂C₂₀F₁₈(1、2 和3), 进一步展示了我们提出的一种新型电子异构体——(非对称型的)笼间电子迁移异构体. 1、2 和3 具有显著不同的偶极矩. 由于都存在两个氧化还原中心, 它们属于一种非金属型的新型Robin-Day II-III 分子. 对于1 和3, 额外电子分别定域在C₂₄F₂₂和C₂₀F₁₈笼里(Robin-Day II); 对于2, 额外电子则离域于两个非对称的笼中(Robin-Day III). 值得注意的是, 在y 轴方向上外加-0.0004和-0.0008 a.u.的临界电场(E_c)时可分别使1 的额外电子从C₂₄F₂₂笼中部分和全部地迁移到C₂₀F₁₈笼中, 即实现从1 到2 再到3 的转化; 当E_c为0.0004 a.u.时, 3 的额外电子从C₂₀F₁₈笼中全部迁移到了C₂₄F₂₂笼中, 即3 未经过2 直接转化成了1.     

全氟辛基磺酰亚胺稀土(Ⅲ)催化氟两相Friedel-Crafts烷基化反应

制备了全氟辛基磺酰亚胺盐(M[N(SO2C8F17)2]n,n:3,4),并用于催化氟两相烷基化反应。考察了催化剂种类、反应时间、反应温度和催化剂用量对烷基化反应的影响,同时探讨了Yb[N(SO2C8F17)2]3对烷基化试剂摩尔比为0.2%时,催化烷基化试剂与不同芳烃的反应,表明Yb[N(SO2C8F17)2]3是一种有效的烷基化催化剂。含有催化剂的氟相通过简单的相分离后,可回收利用。氟相重复使用5次,其催化活性降低不大。     

两种邻、间手性二醇的区域选择性取代反应研究

对两种邻、间手性二醇的区域选择性取代反应进行了研究. 以(R)-(－)-1,3-丁二醇(1)为起始原料, 在各种有机碱存在下, 先合成C¹-位单磺酸酯, 进行C¹-位的单醚化取代, 均有非区域选择性的单(双)取代物生成. 若用SOCl₂处理1, 使其首先生成环状亚硫酸酯中间体5, 苯硫酚在2% Na₂CO₃存在下可和其发生高区域选择性取代反应, 生成 (R)-(－)-3-羟基-丁基苯硫醚(3). 以同样的方法使(S,R)-(＋)-1-(6-氟-2-色满基)-1,2-乙二醇(6)和SOCl₂反应生成环状亚硫酸酯(9), 再和苄胺反应, 也可发生高区域选择性取代, 生成 (S,R)-(＋)-2-苄氨基-1-(6-氟-2-色满基)-乙醇(8). 该反应方法具有高区域选择性, 产物有高旋光纯度、高产率.     

在氟溶剂中的绿色酯化反应

以全氟壬烯为氟溶剂, 对物质的量的羧酸和醇的酯化反应进行了系统研究. 在不移走生成物的条件下, 酯与全氟壬烯能形成氟两相体系而脱离酯化可逆反应体系, 促进反应平衡右移, 使收率提高10%～47%, 氟溶剂通过冷却和简单的相分离, 就可回收并直接套用. 氟溶剂在有机相中的损失小. 在氟溶剂中的酯化反应回流温度有较大幅度的下降.     

Eu(NTf2)3催化吲哚与醛(酮)反应合成二吲哚基甲烷

二(三氟甲基磺酰)亚胺铕(III) [Eu(NTf₂)₃, Tf＝SO₂CF₃]作催化剂, 吲哚与醛(酮)在室温下发生亲电取代反应合成了一系列二吲哚基甲烷, 产率85%～98%. 该法反应条件温和、时间短、催化剂用量少且可以回收重复使用.     

Mannich-type reaction of (1-methoxy-2-methylpropenyloxy)trimethylsilane with arylaldehydes and aromatic amines catalyzed by perfluorinated rare earth metal salts in fluorous phase

In this paper, we describe a useful Mannich-type reaction in fluorous phase. By use of perfluorodecalin (C₁₀F₁₈, cis- and trans-mixture) as a fluorous solvent and perfluorinated rare earth metal salts such as Sc(OSO₂C₈F₁₇)₃ or Yb(OSO₂C₈F₁₇)₃ (2.0 mol%) as a catalyst, the Mannich-type reaction of arylaldehydes with aromatic amines and (1-methoxy-2-methylpropenyloxy)trimethylsilane can be performed for many times without reloading the catalyst and the fluorous solvent.     

Rare earth(III) perfluorooctanesulfonates catalyzed Friedel-Crafts alkylation in fluorous biphase system

The catalyst of rare earth(III) perfluorooctanesulfonates (RE(OSO₂C₈F₁₇)₃, RE = Sc, Y, La-Lu) were prepared from either rare earth chlorides(III) or oxides and perfluorooctanesulfonic acid. The perflates thus obtained act as novel catalysts for Friedel-Crafts alkylation in fluorous biphasic system. Perfluorohexane (C₆F₁₄), perfluoromethylcyclohexane (C₇F₁₄), perfluorotoluene (C₇F₈), perfluorooctane (C₈F₁₈), perfluorooctyl bromide (C₈F₁₇Br) and perfluorodecalin (C₁₀F₁₈, cis- and trans-mixture) can be used as fluorous solvents for this reaction. By simple separation of the fluorous phase containing only catalyst, alkylation can be repeated many times.     

Rare earth(III) perfluorooctane sulfonates and perfluorooctanesulfonic acid in fluorous solvents: Novel and recyclable catalytic systems for Friedel-Crafts acylation of unactivated benzenes

Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes, such as chlorobenzene and fluorobenzene, was successfully accomplished using rare earth(III) perfluorooctane sulfonates (RE(OPf)₃), RE = Sc, Y, La ∼ Lu) and perfluorooctanesulfonic acid (PfOH) as catalysts in fluorous solvents. Solutions of Yb(OPf)₃ and PfOH in perfluorodecalin (C₁₀F₁₈, cis and trans-mixture) are the most suitable catalytic system, with catalyst loading as low as 0.4%mol leading to clean, high-yielding benzoylation of a variety of unactivated benzenes. By simple separation of the fluorous phase containing only catalyst, acylation can be repeated several times.     

Heptadecafluorooctanesulfonic acid (C8F17SO3H) catalyzed intramolecular hydroamination of olefinic sulfonamides in fluorous biphase system (FBS)

A practical, efficient, and environmentally benign intramolecular hydroamination of olefinic sulfonamides was carried out in fluorous biphase system (FBS) using commercially available heptadecafluorooctanesulfonic acid (C₈F₁₇SO₃H) as a catalyst and perfluorodecaline (C₁₀F₁₈, cis- and trans- mixture) as a fluorous solvent to produce the corresponding cyclic products in good yields. The Brønsted acid of C₈F₁₇SO₃H is easily recovered and recycled at least five times.     

Recyclable hafnium(IV) bis(perfluorooctanesulfonyl)amide complex for catalytic Friedel-Crafts acylation and Prins reaction in fluorous biphase system

In fluorous biphase system, hafnium(IV) bis(perfluorooctanesulfonyl)amide complex (Hf[N(SO₂C₈F₁₇)₂]₄) was found to be a highly reactive and recyclable Lewis acid catalyst for Friedel-Crafts acylation and Prins reaction at significantly low catalyst loadings (≤1 mol%). In these reactions, Hf[N(SO₂C₈F₁₇)₂]₄ is selectively soluble in the lower fluorous phase and can be recovered simply by phase separation. Furthermore, the catalyst can be reused without decrease of activity.     

Yb[N(SO2C8F17)2]3-catalyzed allylation of 1,3-dicarbonyl compounds with allylic alcohols in a fluorous biphase system

Allylation of 1,3-dicarbonyl compounds with allylic alcohols was successfully accomplished using rare earth metal (III) bis(perfluorooctanesulfonyl)imide [RE(NPf₂)₃, RE = La∼Lu] as catalysts in fluorous solvents. Ytterbium bis(perfluorooctanesulfonyl)imide [Yb(NPf₂)₃] catalyzes the high efficient reaction of allylation in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.     

Di(1H,1H,2H,2H-perfluorooctyl)-dibenzo-18-crown-6: A “light fluorous” recyclable phase transfer catalyst

A series of dibenzo-18-crown-6 lariat ethers containing two C₇H₁₅ (11), (CH₂)₂C₆F₁₃ (14), (CH₂)₂C₈F₁₇ (15), NHC₇H₁₅ (18) and NHCH₂C₆F₁₃ (19) sidearms were prepared and the single crystal X-ray structure of cis-4,4′-di(1H,1H,2H,2H-perfluorodecyl)-dibenzo-18-crown-6 (15a) is reported. The “light fluorous” dibenzo-18-crown-6 ether (14) has emerged as a stable and robust PTC catalyst, which can be recycled efficiently by fluorous solid-phase extraction, and gives better PTC catalytic activity compared to the parent, non-fluorinated PTC catalyst, dibenzo-18-crown-6, and the alkylated derivative (11) in aliphatic and aromatic nucleophilic substitutions.     

Ytterbium perfluorooctanesulfonate as an efficient and recoverable catalyst for the synthesis of trisubstituted imidazoles

Synthesis of trisubstituted imidazoles was successfully accomplished using rare earth(III) perfluorooctanesulfonates (RE(OPf)₃), RE = Sc, Y, La-Lu as catalysts in fluorous solvents. Ytterbium perfluorooctanesulfonates (Yb(OPf)₃) catalyze the high efficient synthesis of trisubstituted imidazoles in fluorous solvents. By simple separation, fluorous phase containing only catalyst can be reused several times.     

Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition

Air-stable titanocene bis(perfluorooctanesulfonate) [Cp₂Ti(OSO₂C₈F₁₇)₂] that shows high Lewis acidity was prepared from Cp₂TiCl₂ and AgOSO₂C₈F₁₇. The compound was characterized by different techniques, and examined as a catalyst for acylation reactions. It was found that using equimolar acetic anhydride as acetylating agent and under solvent-free condition, Cp₂Ti(OSO₂C₈F₁₇)₂ exhibits high activity and selectivity in the acetylation of various alcohols, phenols, thiols, and amines. Also, good catalytic efficiency is observed in the acylation of 2-phenylethanol across various acylating reagents. The catalyst can be reused without loss of activity in a test of ten cycles. The Cp₂Ti(OSO₂C₈F₁₇)₂ catalyst affords a simple, efficient and general method for the acylation of alcohols, phenols, thiols, and amines.     

Tin(IV) bis(perfluoroalkanesulfonyl)amide complex as a highly selective Lewis acid catalyst for Baeyer-Villiger oxidation using hydrogen peroxide in a fluorous recyclable phase

Sn[N(SO₂C₈F₁₇)₂]₄ catalyst was shown to give an excellent yield and selectivity in a fluorous biphasic catalytic system for Baeyer-Villiger oxidation of cyclic ketones by 35% aqueous hydrogen peroxide, a green, safe and cheap oxidant. Furthermore, the catalyst was completely recovered and reused in the fluorous immobilized phase without loss of activity.